[INFO] fetching crate rust-cheatsheet 0.1.0...
[INFO] building rust-cheatsheet-0.1.0 against master#ad85bc524b1ad696e42061ad8338d382dffbdbe5 for pr-146237-1
[INFO] extracting crate rust-cheatsheet 0.1.0 into /workspace/builds/worker-2-tc1/source
[INFO] started tweaking crates.io crate rust-cheatsheet 0.1.0
[INFO] finished tweaking crates.io crate rust-cheatsheet 0.1.0
[INFO] tweaked toml for crates.io crate rust-cheatsheet 0.1.0 written to /workspace/builds/worker-2-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate rust-cheatsheet 0.1.0 on toolchain ad85bc524b1ad696e42061ad8338d382dffbdbe5
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ad85bc524b1ad696e42061ad8338d382dffbdbe5" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate crates.io crate rust-cheatsheet 0.1.0 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ad85bc524b1ad696e42061ad8338d382dffbdbe5" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+ad85bc524b1ad696e42061ad8338d382dffbdbe5" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 9930aa2f3b5fad68ecc4147dd17ec50e852e134d155d608d281f465d64019eb0
[INFO] running `Command { std: "docker" "start" "-a" "9930aa2f3b5fad68ecc4147dd17ec50e852e134d155d608d281f465d64019eb0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "9930aa2f3b5fad68ecc4147dd17ec50e852e134d155d608d281f465d64019eb0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9930aa2f3b5fad68ecc4147dd17ec50e852e134d155d608d281f465d64019eb0", kill_on_drop: false }`
[INFO] [stdout] 9930aa2f3b5fad68ecc4147dd17ec50e852e134d155d608d281f465d64019eb0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+ad85bc524b1ad696e42061ad8338d382dffbdbe5" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] f465804eed9dedb149df15655f70ca8bb4210af153fd6198350964e420eaaa3b
[INFO] running `Command { std: "docker" "start" "-a" "f465804eed9dedb149df15655f70ca8bb4210af153fd6198350964e420eaaa3b", kill_on_drop: false }`
[INFO] [stderr]    Compiling rust-cheatsheet v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `c1`
[INFO] [stdout]   --> src/lib.rs:87:13
[INFO] [stdout]    |
[INFO] [stdout] 87 |     pub fn mix(c1: PrimaryColor, c2: PrimaryColor) -> SecondaryColor {
[INFO] [stdout]    |                ^^ help: if this is intentional, prefix it with an underscore: `_c1`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `c2`
[INFO] [stdout]   --> src/lib.rs:87:31
[INFO] [stdout]    |
[INFO] [stdout] 87 |     pub fn mix(c1: PrimaryColor, c2: PrimaryColor) -> SecondaryColor {
[INFO] [stdout]    |                                  ^^ help: if this is intentional, prefix it with an underscore: `_c2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `guess`
[INFO] [stdout]  --> src/data-types.rs:9:6
[INFO] [stdout]   |
[INFO] [stdout] 9 |     let guess: u32 = "43".parse().expect("this is not a number");    // works:
[INFO] [stdout]   |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_guess`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:12:6
[INFO] [stdout]    |
[INFO] [stdout] 12 |     let x: i8;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `user3`
[INFO] [stdout]   --> src/structs/structs1.rs:18:6
[INFO] [stdout]    |
[INFO] [stdout] 18 |     let user3 = User {
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_user3`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:13:6
[INFO] [stdout]    |
[INFO] [stdout] 13 |     let x: u8;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:14:6
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let x: i16;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:15:6
[INFO] [stdout]    |
[INFO] [stdout] 15 |     let x: u16;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:16:6
[INFO] [stdout]    |
[INFO] [stdout] 16 |     let x: i32;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:17:6
[INFO] [stdout]    |
[INFO] [stdout] 17 |     let x: u32;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:18:6
[INFO] [stdout]    |
[INFO] [stdout] 18 |     let x: i64;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:19:6
[INFO] [stdout]    |
[INFO] [stdout] 19 |     let x: u64;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:20:6
[INFO] [stdout]    |
[INFO] [stdout] 20 |     let x: i128;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:21:6
[INFO] [stdout]    |
[INFO] [stdout] 21 |     let x: u128;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:22:6
[INFO] [stdout]    |
[INFO] [stdout] 22 |     let x: isize;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:23:6
[INFO] [stdout]    |
[INFO] [stdout] 23 |     let x: usize;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `black`
[INFO] [stdout]   --> src/structs/structs1.rs:26:6
[INFO] [stdout]    |
[INFO] [stdout] 26 |     let black = Color(0, 0, 0);
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_black`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `oirigin`
[INFO] [stdout]   --> src/structs/structs1.rs:27:6
[INFO] [stdout]    |
[INFO] [stdout] 27 |     let oirigin = Point(0, 0, 0);
[INFO] [stdout]    |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_oirigin`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `0`, `1`, and `2` are never read
[INFO] [stdout]   --> src/structs/structs1.rs:24:15
[INFO] [stdout]    |
[INFO] [stdout] 24 |     struct Color(i32, i32, i32);
[INFO] [stdout]    |            ----- ^^^  ^^^  ^^^
[INFO] [stdout]    |            |
[INFO] [stdout]    |            fields in this struct
[INFO] [stdout]    |
[INFO] [stdout]    = help: consider removing these fields
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `0`, `1`, and `2` are never read
[INFO] [stdout]   --> src/structs/structs1.rs:25:15
[INFO] [stdout]    |
[INFO] [stdout] 25 |     struct Point(i32, i32, i32);
[INFO] [stdout]    |            ----- ^^^  ^^^  ^^^
[INFO] [stdout]    |            |
[INFO] [stdout]    |            fields in this struct
[INFO] [stdout]    |
[INFO] [stdout]    = help: consider removing these fields
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `username`, `sign_in_count`, and `active` are never read
[INFO] [stdout]   --> src/structs/structs1.rs:52:2
[INFO] [stdout]    |
[INFO] [stdout] 51 | struct User {
[INFO] [stdout]    |        ---- fields in this struct
[INFO] [stdout] 52 |     username: String,
[INFO] [stdout]    |     ^^^^^^^^
[INFO] [stdout] 53 |     email: String,
[INFO] [stdout] 54 |     sign_in_count: u64,
[INFO] [stdout]    |     ^^^^^^^^^^^^^
[INFO] [stdout] 55 |     active: bool,
[INFO] [stdout]    |     ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:26:6
[INFO] [stdout]    |
[INFO] [stdout] 26 |     let x = 2.0;    // defaults to f64
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]   --> src/data-types.rs:27:6
[INFO] [stdout]    |
[INFO] [stdout] 27 |     let y: f32 = 3.0;     // f32
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `t`
[INFO] [stdout]   --> src/data-types.rs:30:6
[INFO] [stdout]    |
[INFO] [stdout] 30 |     let t = true;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_t`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/data-types.rs:31:6
[INFO] [stdout]    |
[INFO] [stdout] 31 |     let f: bool = false;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `c`
[INFO] [stdout]   --> src/data-types.rs:34:6
[INFO] [stdout]    |
[INFO] [stdout] 34 |     let c = 'z';    // char
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_c`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `z`
[INFO] [stdout]   --> src/data-types.rs:37:6
[INFO] [stdout]    |
[INFO] [stdout] 37 |     let z = 'ℤ';    // char
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_z`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `heart_eyed_cat`
[INFO] [stdout]   --> src/data-types.rs:38:6
[INFO] [stdout]    |
[INFO] [stdout] 38 |     let heart_eyed_cat = '😻';    // char
[INFO] [stdout]    |         ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_heart_eyed_cat`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:45:7
[INFO] [stdout]    |
[INFO] [stdout] 45 |     let (x, y, z) = tup;
[INFO] [stdout]    |          ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `z`
[INFO] [stdout]   --> src/data-types.rs:45:13
[INFO] [stdout]    |
[INFO] [stdout] 45 |     let (x, y, z) = tup;
[INFO] [stdout]    |                ^ help: if this is intentional, prefix it with an underscore: `_z`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `five_hundred`
[INFO] [stdout]   --> src/data-types.rs:48:6
[INFO] [stdout]    |
[INFO] [stdout] 48 |     let five_hundred = tup.0;
[INFO] [stdout]    |         ^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_five_hundred`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `six_point_four`
[INFO] [stdout]   --> src/data-types.rs:49:9
[INFO] [stdout]    |
[INFO] [stdout] 49 |     let six_point_four =tup.1;
[INFO] [stdout]    |         ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_six_point_four`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `one`
[INFO] [stdout]   --> src/data-types.rs:50:9
[INFO] [stdout]    |
[INFO] [stdout] 50 |     let one = tup.2;
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_one`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]   --> src/data-types.rs:53:6
[INFO] [stdout]    |
[INFO] [stdout] 53 |     let a = [1, 2, 3, 4, 5];
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]   --> src/data-types.rs:55:6
[INFO] [stdout]    |
[INFO] [stdout] 55 |     let a: [i32; 5] = [1,2,3,4,5];    // an array of 5 i32's
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `fisrt`
[INFO] [stdout]   --> src/data-types.rs:57:6
[INFO] [stdout]    |
[INFO] [stdout] 57 |     let fisrt =a[0];
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_fisrt`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]  --> src/bin/collections/strings.rs:5:10
[INFO] [stdout]   |
[INFO] [stdout] 5 |     let mut s = String::new();      // type: String
[INFO] [stdout]   |             ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]  --> src/bin/collections/strings.rs:7:6
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let s = data.to_string();      // type: String
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]  --> src/bin/collections/strings.rs:8:6
[INFO] [stdout]   |
[INFO] [stdout] 8 |     let s = String::from("initial contents");
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:11:6
[INFO] [stdout]    |
[INFO] [stdout] 11 |     let hello = String::from("السلام عليكم");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:12:9
[INFO] [stdout]    |
[INFO] [stdout] 12 |     let hello = String::from("Dobrý den");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:13:9
[INFO] [stdout]    |
[INFO] [stdout] 13 |     let hello = String::from("Hello");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:14:9
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let hello = String::from("שָׁלוֹם");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:15:9
[INFO] [stdout]    |
[INFO] [stdout] 15 |     let hello = String::from("नमस्ते");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:16:9
[INFO] [stdout]    |
[INFO] [stdout] 16 |     let hello = String::from("こんにちは");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:17:9
[INFO] [stdout]    |
[INFO] [stdout] 17 |     let hello = String::from("안녕하세요");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:18:9
[INFO] [stdout]    |
[INFO] [stdout] 18 |     let hello = String::from("你好");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:19:9
[INFO] [stdout]    |
[INFO] [stdout] 19 |     let hello = String::from("Olá");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:20:9
[INFO] [stdout]    |
[INFO] [stdout] 20 |     let hello = String::from("Здравствуйте");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:21:9
[INFO] [stdout]    |
[INFO] [stdout] 21 |     let hello = String::from("Hola");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s3`
[INFO] [stdout]   --> src/bin/collections/strings.rs:39:6
[INFO] [stdout]    |
[INFO] [stdout] 39 |     let s3 = s1 + &s2;    // NOTE: s1 has been moved here and can no longer be used
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_s3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/bin/collections/strings.rs:46:9
[INFO] [stdout]    |
[INFO] [stdout] 46 |     let s = format!("{}-{}-{}", s1, s2, s3);
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s1`
[INFO] [stdout]   --> src/bin/collections/strings.rs:50:6
[INFO] [stdout]    |
[INFO] [stdout] 50 |     let s1 = String::from("hello");
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_s1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:53:6
[INFO] [stdout]    |
[INFO] [stdout] 53 |     let hello = String::from("Hola");    // len is 4 each character in UTF-8 is 1 byte
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:54:6
[INFO] [stdout]    |
[INFO] [stdout] 54 |     let hello = String::from("З3дравствуйте");    // len is 24 not 12
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/bin/collections/strings.rs:57:6
[INFO] [stdout]    |
[INFO] [stdout] 57 |     let s = &hello[0..4];    // type: &str (actual bytes)
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v`
[INFO] [stdout]   --> src/enums/enums2.rs:19:6
[INFO] [stdout]    |
[INFO] [stdout] 19 |     let v = value_in_cents(c);
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_v`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `six`
[INFO] [stdout]   --> src/enums/enums2.rs:27:6
[INFO] [stdout]    |
[INFO] [stdout] 27 |     let six = plus_one(five);
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_six`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]  --> src/bin/collections/strings.rs:5:6
[INFO] [stdout]   |
[INFO] [stdout] 5 |     let mut s = String::new();      // type: String
[INFO] [stdout]   |         ----^
[INFO] [stdout]   |         |
[INFO] [stdout]   |         help: remove this `mut`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `none`
[INFO] [stdout]   --> src/enums/enums2.rs:28:6
[INFO] [stdout]    |
[INFO] [stdout] 28 |     let none = plus_one(None);
[INFO] [stdout]    |         ^^^^
[INFO] [stdout]    |
[INFO] [stdout] help: if this is intentional, prefix it with an underscore
[INFO] [stdout]    |
[INFO] [stdout] 28 |     let _none = plus_one(None);
[INFO] [stdout]    |         +
[INFO] [stdout] help: you might have meant to pattern match on the similarly named variant `None`
[INFO] [stdout]    |
[INFO] [stdout] 28 -     let none = plus_one(None);
[INFO] [stdout] 28 +     let std::prelude::v1::None = plus_one(None);
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `count` is assigned to, but never used
[INFO] [stdout]   --> src/enums/enums2.rs:54:10
[INFO] [stdout]    |
[INFO] [stdout] 54 |     let mut count = 0;
[INFO] [stdout]    |             ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: consider using `_count` instead
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `count` is never read
[INFO] [stdout]   --> src/enums/enums2.rs:59:3
[INFO] [stdout]    |
[INFO] [stdout] 59 |         count += 1;
[INFO] [stdout]    |         ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout]    = note: `#[warn(unused_assignments)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variants `Penny` and `Nickel` are never constructed
[INFO] [stdout]  --> src/enums/enums2.rs:4:2
[INFO] [stdout]   |
[INFO] [stdout] 3 | enum Coin {
[INFO] [stdout]   |      ---- variants in this enum
[INFO] [stdout] 4 |     Penny,
[INFO] [stdout]   |     ^^^^^
[INFO] [stdout] 5 |     Nickel,
[INFO] [stdout]   |     ^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/bin/iterators.rs:93:6
[INFO] [stdout]    |
[INFO] [stdout] 93 |     let x: Vec<_> = v1.iter().map(|x|  x + 1).collect();
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Shoe` is never constructed
[INFO] [stdout]  --> src/bin/iterators.rs:5:8
[INFO] [stdout]   |
[INFO] [stdout] 5 | struct Shoe {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `shoes_in_size` is never used
[INFO] [stdout]   --> src/bin/iterators.rs:10:4
[INFO] [stdout]    |
[INFO] [stdout] 10 | fn shoes_in_size(shoes: Vec<Shoe>, shoe_size: u32) -> Vec<Shoe> {
[INFO] [stdout]    |    ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]   --> src/ownership.rs:14:6
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let y = x;    // copies x to y
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s2`
[INFO] [stdout]   --> src/ownership.rs:20:7
[INFO] [stdout]    |
[INFO] [stdout] 20 |         let s2 = s1;    // s1 is considered invalid now
[INFO] [stdout]    |             ^^ help: if this is intentional, prefix it with an underscore: `_s2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s1`
[INFO] [stdout]   --> src/ownership.rs:64:6
[INFO] [stdout]    |
[INFO] [stdout] 64 |     let s1 = gives_ownership();
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_s1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s3`
[INFO] [stdout]   --> src/ownership.rs:66:6
[INFO] [stdout]    |
[INFO] [stdout] 66 |     let s3 = takes_and_gives_back(s2);    // takes s2 then gives it back
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_s3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s2`
[INFO] [stdout]   --> src/ownership.rs:70:7
[INFO] [stdout]    |
[INFO] [stdout] 70 |     let (s2, len) = calculate_length(s1);    // rember s1 is moved into function 
[INFO] [stdout]    |          ^^ help: if this is intentional, prefix it with an underscore: `_s2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `len`
[INFO] [stdout]   --> src/ownership.rs:70:11
[INFO] [stdout]    |
[INFO] [stdout] 70 |     let (s2, len) = calculate_length(s1);    // rember s1 is moved into function 
[INFO] [stdout]    |              ^^^ help: if this is intentional, prefix it with an underscore: `_len`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/ownership.rs:74:20
[INFO] [stdout]    |
[INFO] [stdout] 74 | fn take_ownership (s: String) {
[INFO] [stdout]    |                    ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `n`
[INFO] [stdout]   --> src/ownership.rs:78:15
[INFO] [stdout]    |
[INFO] [stdout] 78 | fn makes_copy(n :i32) {
[INFO] [stdout]    |               ^ help: if this is intentional, prefix it with an underscore: `_n`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `rect1`
[INFO] [stdout]   --> src/structs/structs2.rs:15:6
[INFO] [stdout]    |
[INFO] [stdout] 15 |     let rect1 = Rectangle {
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_rect1`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `width` and `height` are never read
[INFO] [stdout]  --> src/structs/structs2.rs:4:2
[INFO] [stdout]   |
[INFO] [stdout] 3 | struct Rectangle {
[INFO] [stdout]   |        --------- fields in this struct
[INFO] [stdout] 4 |     width: u32,
[INFO] [stdout]   |     ^^^^^
[INFO] [stdout] 5 |     height: u32,
[INFO] [stdout]   |     ^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `width` and `height` are never read
[INFO] [stdout]   --> src/structs/structs2.rs:10:2
[INFO] [stdout]    |
[INFO] [stdout]  9 | struct RectangleDebug {
[INFO] [stdout]    |        -------------- fields in this struct
[INFO] [stdout] 10 |     width: u32,
[INFO] [stdout]    |     ^^^^^
[INFO] [stdout] 11 |     height: u32
[INFO] [stdout]    |     ^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `RectangleDebug` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `len`
[INFO] [stdout]  --> src/references.rs:6:6
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let len = calculate_length(&s1);
[INFO] [stdout]   |         ^^^ help: if this is intentional, prefix it with an underscore: `_len`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r1`
[INFO] [stdout]   --> src/references.rs:22:7
[INFO] [stdout]    |
[INFO] [stdout] 22 |         let r1 = &mut s;
[INFO] [stdout]    |             ^^ help: if this is intentional, prefix it with an underscore: `_r1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r1`
[INFO] [stdout]   --> src/references.rs:29:6
[INFO] [stdout]    |
[INFO] [stdout] 29 |     let r1 = &s; // no problem
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_r1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r2`
[INFO] [stdout]   --> src/references.rs:30:6
[INFO] [stdout]    |
[INFO] [stdout] 30 |     let r2 = &s; // no problem
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_r2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/references.rs:28:6
[INFO] [stdout]    |
[INFO] [stdout] 28 |     let mut s = String::from("hello");
[INFO] [stdout]    |         ----^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `some_string`
[INFO] [stdout]   --> src/references.rs:61:11
[INFO] [stdout]    |
[INFO] [stdout] 61 | fn change(some_string: &String) {
[INFO] [stdout]    |           ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_some_string`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v`
[INFO] [stdout]  --> src/bin/collections/vectors.rs:6:6
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let v: Vec<i32> = Vec::new();
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_v`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `t`
[INFO] [stdout]   --> src/bin/generics/main.rs:79:56
[INFO] [stdout]    |
[INFO] [stdout] 79 | fn some_function<T: Display + Debug, U: Clone + Debug>(t: &T, u: &U) -> i32 {5}
[INFO] [stdout]    |                                                        ^ help: if this is intentional, prefix it with an underscore: `_t`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `does_not_exit`
[INFO] [stdout]   --> src/bin/collections/vectors.rs:34:6
[INFO] [stdout]    |
[INFO] [stdout] 34 |     let does_not_exit = v.get(100);    // type: Option<&i32> // this won't
[INFO] [stdout]    |         ^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_does_not_exit`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> src/bin/collections/vectors.rs:44:6
[INFO] [stdout]    |
[INFO] [stdout] 44 |     for i in &v {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `row`
[INFO] [stdout]   --> src/bin/collections/vectors.rs:57:6
[INFO] [stdout]    |
[INFO] [stdout] 57 |     let row = vec![
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_row`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `median` is never read
[INFO] [stdout]    --> src/bin/collections/vectors.rs:103:10
[INFO] [stdout]     |
[INFO] [stdout] 103 |     let mut median: f64 = -1.0;
[INFO] [stdout]     |             ^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout]     = note: `#[warn(unused_assignments)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `u`
[INFO] [stdout]   --> src/bin/generics/main.rs:79:63
[INFO] [stdout]    |
[INFO] [stdout] 79 | fn some_function<T: Display + Debug, U: Clone + Debug>(t: &T, u: &U) -> i32 {5}
[INFO] [stdout]    |                                                               ^ help: if this is intentional, prefix it with an underscore: `_u`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `t`
[INFO] [stdout]   --> src/bin/generics/main.rs:81:31
[INFO] [stdout]    |
[INFO] [stdout] 81 | fn some_function_where_<T, U>(t: &T, u: &U) -> i32 
[INFO] [stdout]    |                               ^ help: if this is intentional, prefix it with an underscore: `_t`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `u`
[INFO] [stdout]   --> src/bin/generics/main.rs:81:38
[INFO] [stdout]    |
[INFO] [stdout] 81 | fn some_function_where_<T, U>(t: &T, u: &U) -> i32 
[INFO] [stdout]    |                                      ^ help: if this is intentional, prefix it with an underscore: `_u`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `spaces`
[INFO] [stdout]   --> src/variables.rs:28:6
[INFO] [stdout]    |
[INFO] [stdout] 28 |     let spaces = spaces.len();         // type: usize
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_spaces`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `spaces_mut`
[INFO] [stdout]   --> src/variables.rs:30:10
[INFO] [stdout]    |
[INFO] [stdout] 30 |     let mut spaces_mut = "    ";            // type: &str
[INFO] [stdout]    |             ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_spaces_mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/variables.rs:30:6
[INFO] [stdout]    |
[INFO] [stdout] 30 |     let mut spaces_mut = "    ";            // type: &str
[INFO] [stdout]    |         ----^^^^^^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `integer`
[INFO] [stdout]    --> src/bin/generics/main.rs:170:6
[INFO] [stdout]     |
[INFO] [stdout] 170 |     let integer =Point {x: 32, y: 23};
[INFO] [stdout]     |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_integer`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `intfloat`
[INFO] [stdout]    --> src/bin/generics/main.rs:173:6
[INFO] [stdout]     |
[INFO] [stdout] 173 |     let intfloat = Point2 {x: 3.2, y: 32};
[INFO] [stdout]     |         ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_intfloat`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `new_tweet`
[INFO] [stdout]    --> src/bin/generics/main.rs:212:6
[INFO] [stdout]     |
[INFO] [stdout] 212 |     let new_tweet = return_summarizable();
[INFO] [stdout]     |         ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_new_tweet`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `y` is never read
[INFO] [stdout]  --> src/bin/generics/main.rs:7:2
[INFO] [stdout]   |
[INFO] [stdout] 5 | struct Point<T> {
[INFO] [stdout]   |        ----- field in this struct
[INFO] [stdout] 6 |     x: T,
[INFO] [stdout] 7 |     y: T,
[INFO] [stdout]   |     ^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]  --> src/bin/collections/strings.rs:5:10
[INFO] [stdout]   |
[INFO] [stdout] 5 |     let mut s = String::new();      // type: String
[INFO] [stdout]   |             ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]  --> src/bin/collections/strings.rs:7:6
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let s = data.to_string();      // type: String
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]  --> src/bin/collections/strings.rs:8:6
[INFO] [stdout]   |
[INFO] [stdout] 8 |     let s = String::from("initial contents");
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:11:6
[INFO] [stdout]    |
[INFO] [stdout] 11 |     let hello = String::from("السلام عليكم");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:12:9
[INFO] [stdout]    |
[INFO] [stdout] 12 |     let hello = String::from("Dobrý den");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:13:9
[INFO] [stdout]    |
[INFO] [stdout] 13 |     let hello = String::from("Hello");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:14:9
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let hello = String::from("שָׁלוֹם");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:15:9
[INFO] [stdout]    |
[INFO] [stdout] 15 |     let hello = String::from("नमस्ते");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:16:9
[INFO] [stdout]    |
[INFO] [stdout] 16 |     let hello = String::from("こんにちは");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:17:9
[INFO] [stdout]    |
[INFO] [stdout] 17 |     let hello = String::from("안녕하세요");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:18:9
[INFO] [stdout]    |
[INFO] [stdout] 18 |     let hello = String::from("你好");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:19:9
[INFO] [stdout]    |
[INFO] [stdout] 19 |     let hello = String::from("Olá");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:20:9
[INFO] [stdout]    |
[INFO] [stdout] 20 |     let hello = String::from("Здравствуйте");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:21:9
[INFO] [stdout]    |
[INFO] [stdout] 21 |     let hello = String::from("Hola");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s3`
[INFO] [stdout]   --> src/bin/collections/strings.rs:39:6
[INFO] [stdout]    |
[INFO] [stdout] 39 |     let s3 = s1 + &s2;    // NOTE: s1 has been moved here and can no longer be used
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_s3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/bin/collections/strings.rs:46:9
[INFO] [stdout]    |
[INFO] [stdout] 46 |     let s = format!("{}-{}-{}", s1, s2, s3);
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s1`
[INFO] [stdout]   --> src/bin/collections/strings.rs:50:6
[INFO] [stdout]    |
[INFO] [stdout] 50 |     let s1 = String::from("hello");
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_s1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:53:6
[INFO] [stdout]    |
[INFO] [stdout] 53 |     let hello = String::from("Hola");    // len is 4 each character in UTF-8 is 1 byte
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:54:6
[INFO] [stdout]    |
[INFO] [stdout] 54 |     let hello = String::from("З3дравствуйте");    // len is 24 not 12
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/bin/collections/strings.rs:57:6
[INFO] [stdout]    |
[INFO] [stdout] 57 |     let s = &hello[0..4];    // type: &str (actual bytes)
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `x` and `y` are never read
[INFO] [stdout]   --> src/bin/generics/main.rs:11:5
[INFO] [stdout]    |
[INFO] [stdout] 10 | struct Point2<T, U> {
[INFO] [stdout]    |        ------ fields in this struct
[INFO] [stdout] 11 |     x: T,
[INFO] [stdout]    |     ^
[INFO] [stdout] 12 |     y: U,
[INFO] [stdout]    |     ^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `Option` is never used
[INFO] [stdout]   --> src/bin/generics/main.rs:15:6
[INFO] [stdout]    |
[INFO] [stdout] 15 | enum Option<T> {
[INFO] [stdout]    |      ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `Result` is never used
[INFO] [stdout]   --> src/bin/generics/main.rs:20:6
[INFO] [stdout]    |
[INFO] [stdout] 20 | enum Result<T, E> {
[INFO] [stdout]    |      ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `distance_from_origin` is never used
[INFO] [stdout]   --> src/bin/generics/main.rs:32:5
[INFO] [stdout]    |
[INFO] [stdout] 31 | impl Point<f32> {
[INFO] [stdout]    | --------------- method in this implementation
[INFO] [stdout] 32 |     fn distance_from_origin(&self) -> f32 {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `mixup` is never used
[INFO] [stdout]   --> src/bin/generics/main.rs:38:5
[INFO] [stdout]    |
[INFO] [stdout] 37 | impl<T, U> Point2<T, U> {
[INFO] [stdout]    | ----------------------- method in this implementation
[INFO] [stdout] 38 |     fn mixup<V, W>(self, other: Point2<V, W>) -> Point2<T, W> {
[INFO] [stdout]    |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `notify_mult_impl` is never used
[INFO] [stdout]   --> src/bin/generics/main.rs:70:4
[INFO] [stdout]    |
[INFO] [stdout] 70 | fn notify_mult_impl<T: Summary + Minimize>(item: &T) {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `some_function` is never used
[INFO] [stdout]   --> src/bin/generics/main.rs:79:4
[INFO] [stdout]    |
[INFO] [stdout] 79 | fn some_function<T: Display + Debug, U: Clone + Debug>(t: &T, u: &U) -> i32 {5}
[INFO] [stdout]    |    ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `some_function_where_` is never used
[INFO] [stdout]   --> src/bin/generics/main.rs:81:4
[INFO] [stdout]    |
[INFO] [stdout] 81 | fn some_function_where_<T, U>(t: &T, u: &U) -> i32 
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `largest_clone` is never used
[INFO] [stdout]    --> src/bin/generics/main.rs:107:4
[INFO] [stdout]     |
[INFO] [stdout] 107 | fn largest_clone<T: PartialOrd + Clone>(list: &[T]) -> T {
[INFO] [stdout]     |    ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `largest_using_return_ref` is never used
[INFO] [stdout]    --> src/bin/generics/main.rs:118:4
[INFO] [stdout]     |
[INFO] [stdout] 118 | fn largest_using_return_ref<T: PartialOrd>(list: &[T]) -> &T {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Pair` is never constructed
[INFO] [stdout]    --> src/bin/generics/main.rs:130:8
[INFO] [stdout]     |
[INFO] [stdout] 130 | struct Pair<T> {
[INFO] [stdout]     |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]    --> src/bin/generics/main.rs:136:5
[INFO] [stdout]     |
[INFO] [stdout] 135 | impl<T> Pair<T> {
[INFO] [stdout]     | --------------- associated function in this implementation
[INFO] [stdout] 136 |     fn new(x: T, y: T) -> Self {
[INFO] [stdout]     |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `cmp_display` is never used
[INFO] [stdout]    --> src/bin/generics/main.rs:142:5
[INFO] [stdout]     |
[INFO] [stdout] 141 | impl <T: Display + PartialOrd> Pair<T> {
[INFO] [stdout]     | -------------------------------------- method in this implementation
[INFO] [stdout] 142 |     fn cmp_display(&self) { // fn is only implement when generic type of T conform to PartialOrd and Display trait
[INFO] [stdout]     |        ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `content` is never read
[INFO] [stdout]   --> src/bin/generics/traits.rs:31:9
[INFO] [stdout]    |
[INFO] [stdout] 27 | pub struct NewsArticle {
[INFO] [stdout]    |            ----------- field in this struct
[INFO] [stdout] ...
[INFO] [stdout] 31 |     pub content: String,
[INFO] [stdout]    |         ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `reply` and `retweet` are never read
[INFO] [stdout]   --> src/bin/generics/traits.rs:37:9
[INFO] [stdout]    |
[INFO] [stdout] 34 | pub struct Tweet {
[INFO] [stdout]    |            ----- fields in this struct
[INFO] [stdout] ...
[INFO] [stdout] 37 |     pub reply: bool,
[INFO] [stdout]    |         ^^^^^
[INFO] [stdout] 38 |     pub retweet: bool,
[INFO] [stdout]    |         ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait method `summarizeDef` should have a snake case name
[INFO] [stdout]   --> src/bin/generics/traits.rs:14:5
[INFO] [stdout]    |
[INFO] [stdout] 14 |     fn summarizeDef(&self) -> String {
[INFO] [stdout]    |        ^^^^^^^^^^^^ help: convert the identifier to snake case: `summarize_def`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_snake_case)]` (part of `#[warn(nonstandard_style)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]  --> src/bin/collections/strings.rs:5:6
[INFO] [stdout]   |
[INFO] [stdout] 5 |     let mut s = String::new();      // type: String
[INFO] [stdout]   |         ----^
[INFO] [stdout]   |         |
[INFO] [stdout]   |         help: remove this `mut`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `k2`
[INFO] [stdout]   --> src/bin/collections/hashmaps.rs:70:7
[INFO] [stdout]    |
[INFO] [stdout] 70 |         let k2 = String::from("world");
[INFO] [stdout]    |             ^^ help: if this is intentional, prefix it with an underscore: `_k2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `add_two` is never used
[INFO] [stdout]  --> src/bin/testing.rs:6:4
[INFO] [stdout]   |
[INFO] [stdout] 6 | fn add_two(a: i32) -> i32 {
[INFO] [stdout]   |    ^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Rectangle` is never constructed
[INFO] [stdout]   --> src/bin/testing.rs:99:8
[INFO] [stdout]    |
[INFO] [stdout] 99 | struct Rectangle {
[INFO] [stdout]    |        ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]   --> src/functions.rs:13:6
[INFO] [stdout]    |
[INFO] [stdout] 13 |     let y = 6; // is a statement.
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/bin/collections/vectors.rs:52:7
[INFO] [stdout]    |
[INFO] [stdout] 52 |         Int(i32),
[INFO] [stdout]    |         --- ^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         field in this variant
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 52 -         Int(i32),
[INFO] [stdout] 52 +         Int(()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/bin/collections/vectors.rs:53:9
[INFO] [stdout]    |
[INFO] [stdout] 53 |         Float(f64),
[INFO] [stdout]    |         ----- ^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         field in this variant
[INFO] [stdout]    |
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 53 -         Float(f64),
[INFO] [stdout] 53 +         Float(()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/bin/collections/vectors.rs:54:8
[INFO] [stdout]    |
[INFO] [stdout] 54 |         Text(String),
[INFO] [stdout]    |         ---- ^^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         field in this variant
[INFO] [stdout]    |
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 54 -         Text(String),
[INFO] [stdout] 54 +         Text(()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/bin/collections/vectors.rs:67:9
[INFO] [stdout]    |
[INFO] [stdout] 67 |         Valid(f64)
[INFO] [stdout]    |         ----- ^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         field in this variant
[INFO] [stdout]    |
[INFO] [stdout]    = note: `State` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 67 -         Valid(f64)
[INFO] [stdout] 67 +         Valid(())
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `file`
[INFO] [stdout]   --> src/bin/errors.rs:12:6
[INFO] [stdout]    |
[INFO] [stdout] 12 |     let file = match f {
[INFO] [stdout]    |         ^^^^ help: if this is intentional, prefix it with an underscore: `_file`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/bin/errors.rs:24:6
[INFO] [stdout]    |
[INFO] [stdout] 24 |     let f = File::open("hello.txt").unwrap_or_else(|error| {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/bin/errors.rs:36:6
[INFO] [stdout]    |
[INFO] [stdout] 36 |     let f = File::open("hello.txt").unwrap();
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/bin/errors.rs:43:6
[INFO] [stdout]    |
[INFO] [stdout] 43 |     let f =File::open("hello.txt").expect("error message couldn't blah blah...");
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/bin/errors.rs:50:6
[INFO] [stdout]    |
[INFO] [stdout] 50 |         Ok(s) => println!("returned string with data"),
[INFO] [stdout]    |            ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/bin/errors.rs:65:2
[INFO] [stdout]    |
[INFO] [stdout] 65 |     read_username_from_file_oneline("hello.txt");
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 65 |     let _ = read_username_from_file_oneline("hello.txt");
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v`
[INFO] [stdout]  --> src/bin/collections/vectors.rs:6:6
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let v: Vec<i32> = Vec::new();
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_v`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `does_not_exit`
[INFO] [stdout]   --> src/bin/collections/vectors.rs:34:6
[INFO] [stdout]    |
[INFO] [stdout] 34 |     let does_not_exit = v.get(100);    // type: Option<&i32> // this won't
[INFO] [stdout]    |         ^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_does_not_exit`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> src/bin/collections/vectors.rs:44:6
[INFO] [stdout]    |
[INFO] [stdout] 44 |     for i in &v {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `row`
[INFO] [stdout]   --> src/bin/collections/vectors.rs:57:6
[INFO] [stdout]    |
[INFO] [stdout] 57 |     let row = vec![
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_row`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `median` is never read
[INFO] [stdout]    --> src/bin/collections/vectors.rs:103:10
[INFO] [stdout]     |
[INFO] [stdout] 103 |     let mut median: f64 = -1.0;
[INFO] [stdout]     |             ^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout]     = note: `#[warn(unused_assignments)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/bin/collections/vectors.rs:52:7
[INFO] [stdout]    |
[INFO] [stdout] 52 |         Int(i32),
[INFO] [stdout]    |         --- ^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         field in this variant
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 52 -         Int(i32),
[INFO] [stdout] 52 +         Int(()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/bin/collections/vectors.rs:53:9
[INFO] [stdout]    |
[INFO] [stdout] 53 |         Float(f64),
[INFO] [stdout]    |         ----- ^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         field in this variant
[INFO] [stdout]    |
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 53 -         Float(f64),
[INFO] [stdout] 53 +         Float(()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/bin/collections/vectors.rs:54:8
[INFO] [stdout]    |
[INFO] [stdout] 54 |         Text(String),
[INFO] [stdout]    |         ---- ^^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         field in this variant
[INFO] [stdout]    |
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 54 -         Text(String),
[INFO] [stdout] 54 +         Text(()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/bin/collections/vectors.rs:67:9
[INFO] [stdout]    |
[INFO] [stdout] 67 |         Valid(f64)
[INFO] [stdout]    |         ----- ^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         field in this variant
[INFO] [stdout]    |
[INFO] [stdout]    = note: `State` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 67 -         Valid(f64)
[INFO] [stdout] 67 +         Valid(())
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `contents`
[INFO] [stdout]   --> src/main.rs:11:9
[INFO] [stdout]    |
[INFO] [stdout] 11 |     let contents = format!("{}\t{}\n", key, value);
[INFO] [stdout]    |         ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_contents`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `0`, `1`, `2`, and `3` are never read
[INFO] [stdout]   --> src/enums/enums1.rs:12:5
[INFO] [stdout]    |
[INFO] [stdout] 12 |     V4(u8, u8, u8, u8),
[INFO] [stdout]    |     -- ^^  ^^  ^^  ^^
[INFO] [stdout]    |     |
[INFO] [stdout]    |     fields in this variant
[INFO] [stdout]    |
[INFO] [stdout]    = note: `IpAddrKind2` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: consider changing the fields to be of unit type to suppress this warning while preserving the field numbering, or remove the fields
[INFO] [stdout]    |
[INFO] [stdout] 12 -     V4(u8, u8, u8, u8),
[INFO] [stdout] 12 +     V4((), (), (), ()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/enums/enums1.rs:13:5
[INFO] [stdout]    |
[INFO] [stdout] 13 |     V6(String)
[INFO] [stdout]    |     -- ^^^^^^
[INFO] [stdout]    |     |
[INFO] [stdout]    |     field in this variant
[INFO] [stdout]    |
[INFO] [stdout]    = note: `IpAddrKind2` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 13 -     V6(String)
[INFO] [stdout] 13 +     V6(())
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/enums/enums1.rs:19:8
[INFO] [stdout]    |
[INFO] [stdout] 19 |     Write(String),
[INFO] [stdout]    |     ----- ^^^^^^
[INFO] [stdout]    |     |
[INFO] [stdout]    |     field in this variant
[INFO] [stdout]    |
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 19 -     Write(String),
[INFO] [stdout] 19 +     Write(()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `k2`
[INFO] [stdout]   --> src/bin/collections/hashmaps.rs:70:7
[INFO] [stdout]    |
[INFO] [stdout] 70 |         let k2 = String::from("world");
[INFO] [stdout]    |             ^^ help: if this is intentional, prefix it with an underscore: `_k2`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]  --> src/slices.rs:7:6
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let slice = &s[0..2];
[INFO] [stdout]   |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]  --> src/slices.rs:8:6
[INFO] [stdout]   |
[INFO] [stdout] 8 |     let slice = &s[..2];
[INFO] [stdout]   |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]  --> src/slices.rs:9:6
[INFO] [stdout]   |
[INFO] [stdout] 9 |     let slice = &s[3..s.len()];
[INFO] [stdout]   |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]   --> src/slices.rs:10:6
[INFO] [stdout]    |
[INFO] [stdout] 10 |     let slice = &s[3..];
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `word`
[INFO] [stdout]   --> src/slices.rs:22:7
[INFO] [stdout]    |
[INFO] [stdout] 22 |         let word = first_word_better(&s[..]);
[INFO] [stdout]    |             ^^^^ help: if this is intentional, prefix it with an underscore: `_word`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `word`
[INFO] [stdout]   --> src/slices.rs:23:7
[INFO] [stdout]    |
[INFO] [stdout] 23 |         let word = first_word_better(&string_literal[..]);
[INFO] [stdout]    |             ^^^^ help: if this is intentional, prefix it with an underscore: `_word`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `word`
[INFO] [stdout]   --> src/slices.rs:25:7
[INFO] [stdout]    |
[INFO] [stdout] 25 |         let word = first_word_better(string_literal);
[INFO] [stdout]    |             ^^^^ help: if this is intentional, prefix it with an underscore: `_word`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]  --> src/slices.rs:5:6
[INFO] [stdout]   |
[INFO] [stdout] 5 |     let mut s = String::from("hello world");
[INFO] [stdout]   |         ----^
[INFO] [stdout]   |         |
[INFO] [stdout]   |         help: remove this `mut`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 3.81s
[INFO] running `Command { std: "docker" "inspect" "f465804eed9dedb149df15655f70ca8bb4210af153fd6198350964e420eaaa3b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f465804eed9dedb149df15655f70ca8bb4210af153fd6198350964e420eaaa3b", kill_on_drop: false }`
[INFO] [stdout] f465804eed9dedb149df15655f70ca8bb4210af153fd6198350964e420eaaa3b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+ad85bc524b1ad696e42061ad8338d382dffbdbe5" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 9eeb876ee868984d3906b2bb1f9c96211521a11bade95d16b2c480b37dc9a33d
[INFO] running `Command { std: "docker" "start" "-a" "9eeb876ee868984d3906b2bb1f9c96211521a11bade95d16b2c480b37dc9a33d", kill_on_drop: false }`
[INFO] [stdout] warning: unused variable: `c1`
[INFO] [stdout]   --> src/lib.rs:87:13
[INFO] [stdout]    |
[INFO] [stdout] 87 |     pub fn mix(c1: PrimaryColor, c2: PrimaryColor) -> SecondaryColor {
[INFO] [stdout]    |                ^^ help: if this is intentional, prefix it with an underscore: `_c1`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `c2`
[INFO] [stdout]   --> src/lib.rs:87:31
[INFO] [stdout]    |
[INFO] [stdout] 87 |     pub fn mix(c1: PrimaryColor, c2: PrimaryColor) -> SecondaryColor {
[INFO] [stdout]    |                                  ^^ help: if this is intentional, prefix it with an underscore: `_c2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `0`, `1`, `2`, and `3` are never read
[INFO] [stdout]   --> src/enums/enums1.rs:12:5
[INFO] [stdout]    |
[INFO] [stdout] 12 |     V4(u8, u8, u8, u8),
[INFO] [stdout]    |     -- ^^  ^^  ^^  ^^
[INFO] [stdout]    |     |
[INFO] [stdout]    |     fields in this variant
[INFO] [stdout]    |
[INFO] [stdout]    = note: `IpAddrKind2` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: consider changing the fields to be of unit type to suppress this warning while preserving the field numbering, or remove the fields
[INFO] [stdout]    |
[INFO] [stdout] 12 -     V4(u8, u8, u8, u8),
[INFO] [stdout] 12 +     V4((), (), (), ()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/enums/enums1.rs:13:5
[INFO] [stdout]    |
[INFO] [stdout] 13 |     V6(String)
[INFO] [stdout]    |     -- ^^^^^^
[INFO] [stdout]    |     |
[INFO] [stdout]    |     field in this variant
[INFO] [stdout]    |
[INFO] [stdout]    = note: `IpAddrKind2` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 13 -     V6(String)
[INFO] [stdout] 13 +     V6(())
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/enums/enums1.rs:19:8
[INFO] [stdout]    |
[INFO] [stdout] 19 |     Write(String),
[INFO] [stdout]    |     ----- ^^^^^^
[INFO] [stdout]    |     |
[INFO] [stdout]    |     field in this variant
[INFO] [stdout]    |
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 19 -     Write(String),
[INFO] [stdout] 19 +     Write(()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `rect1`
[INFO] [stdout]   --> src/structs/structs2.rs:15:6
[INFO] [stdout]    |
[INFO] [stdout] 15 |     let rect1 = Rectangle {
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_rect1`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling rust-cheatsheet v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: fields `width` and `height` are never read
[INFO] [stdout]  --> src/structs/structs2.rs:4:2
[INFO] [stdout]   |
[INFO] [stdout] 3 | struct Rectangle {
[INFO] [stdout]   |        --------- fields in this struct
[INFO] [stdout] 4 |     width: u32,
[INFO] [stdout]   |     ^^^^^
[INFO] [stdout] 5 |     height: u32,
[INFO] [stdout]   |     ^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `width` and `height` are never read
[INFO] [stdout]   --> src/structs/structs2.rs:10:2
[INFO] [stdout]    |
[INFO] [stdout]  9 | struct RectangleDebug {
[INFO] [stdout]    |        -------------- fields in this struct
[INFO] [stdout] 10 |     width: u32,
[INFO] [stdout]    |     ^^^^^
[INFO] [stdout] 11 |     height: u32
[INFO] [stdout]    |     ^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `RectangleDebug` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v`
[INFO] [stdout]  --> src/bin/collections/vectors.rs:6:6
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let v: Vec<i32> = Vec::new();
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_v`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `does_not_exit`
[INFO] [stdout]   --> src/bin/collections/vectors.rs:34:6
[INFO] [stdout]    |
[INFO] [stdout] 34 |     let does_not_exit = v.get(100);    // type: Option<&i32> // this won't
[INFO] [stdout]    |         ^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_does_not_exit`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> src/bin/collections/vectors.rs:44:6
[INFO] [stdout]    |
[INFO] [stdout] 44 |     for i in &v {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `row`
[INFO] [stdout]   --> src/bin/collections/vectors.rs:57:6
[INFO] [stdout]    |
[INFO] [stdout] 57 |     let row = vec![
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_row`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `median` is never read
[INFO] [stdout]    --> src/bin/collections/vectors.rs:103:10
[INFO] [stdout]     |
[INFO] [stdout] 103 |     let mut median: f64 = -1.0;
[INFO] [stdout]     |             ^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout]     = note: `#[warn(unused_assignments)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/bin/collections/vectors.rs:52:7
[INFO] [stdout]    |
[INFO] [stdout] 52 |         Int(i32),
[INFO] [stdout]    |         --- ^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         field in this variant
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 52 -         Int(i32),
[INFO] [stdout] 52 +         Int(()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/bin/collections/vectors.rs:53:9
[INFO] [stdout]    |
[INFO] [stdout] 53 |         Float(f64),
[INFO] [stdout]    |         ----- ^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         field in this variant
[INFO] [stdout]    |
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 53 -         Float(f64),
[INFO] [stdout] 53 +         Float(()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/bin/collections/vectors.rs:54:8
[INFO] [stdout]    |
[INFO] [stdout] 54 |         Text(String),
[INFO] [stdout]    |         ---- ^^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         field in this variant
[INFO] [stdout]    |
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 54 -         Text(String),
[INFO] [stdout] 54 +         Text(()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/bin/collections/vectors.rs:67:9
[INFO] [stdout]    |
[INFO] [stdout] 67 |         Valid(f64)
[INFO] [stdout]    |         ----- ^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         field in this variant
[INFO] [stdout]    |
[INFO] [stdout]    = note: `State` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 67 -         Valid(f64)
[INFO] [stdout] 67 +         Valid(())
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `len`
[INFO] [stdout]  --> src/references.rs:6:6
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let len = calculate_length(&s1);
[INFO] [stdout]   |         ^^^ help: if this is intentional, prefix it with an underscore: `_len`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r1`
[INFO] [stdout]   --> src/references.rs:22:7
[INFO] [stdout]    |
[INFO] [stdout] 22 |         let r1 = &mut s;
[INFO] [stdout]    |             ^^ help: if this is intentional, prefix it with an underscore: `_r1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r1`
[INFO] [stdout]   --> src/references.rs:29:6
[INFO] [stdout]    |
[INFO] [stdout] 29 |     let r1 = &s; // no problem
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_r1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r2`
[INFO] [stdout]   --> src/references.rs:30:6
[INFO] [stdout]    |
[INFO] [stdout] 30 |     let r2 = &s; // no problem
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_r2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/references.rs:28:6
[INFO] [stdout]    |
[INFO] [stdout] 28 |     let mut s = String::from("hello");
[INFO] [stdout]    |         ----^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `some_string`
[INFO] [stdout]   --> src/references.rs:61:11
[INFO] [stdout]    |
[INFO] [stdout] 61 | fn change(some_string: &String) {
[INFO] [stdout]    |           ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_some_string`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v`
[INFO] [stdout]  --> src/bin/collections/vectors.rs:6:6
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let v: Vec<i32> = Vec::new();
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_v`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `does_not_exit`
[INFO] [stdout]   --> src/bin/collections/vectors.rs:34:6
[INFO] [stdout]    |
[INFO] [stdout] 34 |     let does_not_exit = v.get(100);    // type: Option<&i32> // this won't
[INFO] [stdout]    |         ^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_does_not_exit`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> src/bin/collections/vectors.rs:44:6
[INFO] [stdout]    |
[INFO] [stdout] 44 |     for i in &v {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `row`
[INFO] [stdout]   --> src/bin/collections/vectors.rs:57:6
[INFO] [stdout]    |
[INFO] [stdout] 57 |     let row = vec![
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_row`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `median` is never read
[INFO] [stdout]    --> src/bin/collections/vectors.rs:103:10
[INFO] [stdout]     |
[INFO] [stdout] 103 |     let mut median: f64 = -1.0;
[INFO] [stdout]     |             ^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout]     = note: `#[warn(unused_assignments)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]  --> src/bin/collections/strings.rs:5:10
[INFO] [stdout]   |
[INFO] [stdout] 5 |     let mut s = String::new();      // type: String
[INFO] [stdout]   |             ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]  --> src/bin/collections/strings.rs:7:6
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let s = data.to_string();      // type: String
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]  --> src/bin/collections/strings.rs:8:6
[INFO] [stdout]   |
[INFO] [stdout] 8 |     let s = String::from("initial contents");
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:11:6
[INFO] [stdout]    |
[INFO] [stdout] 11 |     let hello = String::from("السلام عليكم");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:12:9
[INFO] [stdout]    |
[INFO] [stdout] 12 |     let hello = String::from("Dobrý den");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:13:9
[INFO] [stdout]    |
[INFO] [stdout] 13 |     let hello = String::from("Hello");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:14:9
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let hello = String::from("שָׁלוֹם");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:15:9
[INFO] [stdout]    |
[INFO] [stdout] 15 |     let hello = String::from("नमस्ते");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:16:9
[INFO] [stdout]    |
[INFO] [stdout] 16 |     let hello = String::from("こんにちは");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:17:9
[INFO] [stdout]    |
[INFO] [stdout] 17 |     let hello = String::from("안녕하세요");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:18:9
[INFO] [stdout]    |
[INFO] [stdout] 18 |     let hello = String::from("你好");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:19:9
[INFO] [stdout]    |
[INFO] [stdout] 19 |     let hello = String::from("Olá");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:20:9
[INFO] [stdout]    |
[INFO] [stdout] 20 |     let hello = String::from("Здравствуйте");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:21:9
[INFO] [stdout]    |
[INFO] [stdout] 21 |     let hello = String::from("Hola");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s3`
[INFO] [stdout]   --> src/bin/collections/strings.rs:39:6
[INFO] [stdout]    |
[INFO] [stdout] 39 |     let s3 = s1 + &s2;    // NOTE: s1 has been moved here and can no longer be used
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_s3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/bin/collections/strings.rs:46:9
[INFO] [stdout]    |
[INFO] [stdout] 46 |     let s = format!("{}-{}-{}", s1, s2, s3);
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s1`
[INFO] [stdout]   --> src/bin/collections/strings.rs:50:6
[INFO] [stdout]    |
[INFO] [stdout] 50 |     let s1 = String::from("hello");
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_s1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:53:6
[INFO] [stdout]    |
[INFO] [stdout] 53 |     let hello = String::from("Hola");    // len is 4 each character in UTF-8 is 1 byte
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:54:6
[INFO] [stdout]    |
[INFO] [stdout] 54 |     let hello = String::from("З3дравствуйте");    // len is 24 not 12
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/bin/collections/strings.rs:57:6
[INFO] [stdout]    |
[INFO] [stdout] 57 |     let s = &hello[0..4];    // type: &str (actual bytes)
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]  --> src/bin/collections/strings.rs:5:6
[INFO] [stdout]   |
[INFO] [stdout] 5 |     let mut s = String::new();      // type: String
[INFO] [stdout]   |         ----^
[INFO] [stdout]   |         |
[INFO] [stdout]   |         help: remove this `mut`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `k2`
[INFO] [stdout]   --> src/bin/collections/hashmaps.rs:70:7
[INFO] [stdout]    |
[INFO] [stdout] 70 |         let k2 = String::from("world");
[INFO] [stdout]    |             ^^ help: if this is intentional, prefix it with an underscore: `_k2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/bin/collections/vectors.rs:52:7
[INFO] [stdout]    |
[INFO] [stdout] 52 |         Int(i32),
[INFO] [stdout]    |         --- ^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         field in this variant
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 52 -         Int(i32),
[INFO] [stdout] 52 +         Int(()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/bin/collections/vectors.rs:53:9
[INFO] [stdout]    |
[INFO] [stdout] 53 |         Float(f64),
[INFO] [stdout]    |         ----- ^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         field in this variant
[INFO] [stdout]    |
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 53 -         Float(f64),
[INFO] [stdout] 53 +         Float(()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/bin/collections/vectors.rs:54:8
[INFO] [stdout]    |
[INFO] [stdout] 54 |         Text(String),
[INFO] [stdout]    |         ---- ^^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         field in this variant
[INFO] [stdout]    |
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 54 -         Text(String),
[INFO] [stdout] 54 +         Text(()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/bin/collections/vectors.rs:67:9
[INFO] [stdout]    |
[INFO] [stdout] 67 |         Valid(f64)
[INFO] [stdout]    |         ----- ^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         field in this variant
[INFO] [stdout]    |
[INFO] [stdout]    = note: `State` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 67 -         Valid(f64)
[INFO] [stdout] 67 +         Valid(())
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `t`
[INFO] [stdout]   --> src/bin/generics/main.rs:79:56
[INFO] [stdout]    |
[INFO] [stdout] 79 | fn some_function<T: Display + Debug, U: Clone + Debug>(t: &T, u: &U) -> i32 {5}
[INFO] [stdout]    |                                                        ^ help: if this is intentional, prefix it with an underscore: `_t`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `u`
[INFO] [stdout]   --> src/bin/generics/main.rs:79:63
[INFO] [stdout]    |
[INFO] [stdout] 79 | fn some_function<T: Display + Debug, U: Clone + Debug>(t: &T, u: &U) -> i32 {5}
[INFO] [stdout]    |                                                               ^ help: if this is intentional, prefix it with an underscore: `_u`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `t`
[INFO] [stdout]   --> src/bin/generics/main.rs:81:31
[INFO] [stdout]    |
[INFO] [stdout] 81 | fn some_function_where_<T, U>(t: &T, u: &U) -> i32 
[INFO] [stdout]    |                               ^ help: if this is intentional, prefix it with an underscore: `_t`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `u`
[INFO] [stdout]   --> src/bin/generics/main.rs:81:38
[INFO] [stdout]    |
[INFO] [stdout] 81 | fn some_function_where_<T, U>(t: &T, u: &U) -> i32 
[INFO] [stdout]    |                                      ^ help: if this is intentional, prefix it with an underscore: `_u`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `integer`
[INFO] [stdout]    --> src/bin/generics/main.rs:170:6
[INFO] [stdout]     |
[INFO] [stdout] 170 |     let integer =Point {x: 32, y: 23};
[INFO] [stdout]     |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_integer`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `intfloat`
[INFO] [stdout]    --> src/bin/generics/main.rs:173:6
[INFO] [stdout]     |
[INFO] [stdout] 173 |     let intfloat = Point2 {x: 3.2, y: 32};
[INFO] [stdout]     |         ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_intfloat`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `new_tweet`
[INFO] [stdout]    --> src/bin/generics/main.rs:212:6
[INFO] [stdout]     |
[INFO] [stdout] 212 |     let new_tweet = return_summarizable();
[INFO] [stdout]     |         ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_new_tweet`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `y` is never read
[INFO] [stdout]  --> src/bin/generics/main.rs:7:2
[INFO] [stdout]   |
[INFO] [stdout] 5 | struct Point<T> {
[INFO] [stdout]   |        ----- field in this struct
[INFO] [stdout] 6 |     x: T,
[INFO] [stdout] 7 |     y: T,
[INFO] [stdout]   |     ^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `x` and `y` are never read
[INFO] [stdout]   --> src/bin/generics/main.rs:11:5
[INFO] [stdout]    |
[INFO] [stdout] 10 | struct Point2<T, U> {
[INFO] [stdout]    |        ------ fields in this struct
[INFO] [stdout] 11 |     x: T,
[INFO] [stdout]    |     ^
[INFO] [stdout] 12 |     y: U,
[INFO] [stdout]    |     ^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `Option` is never used
[INFO] [stdout]   --> src/bin/generics/main.rs:15:6
[INFO] [stdout]    |
[INFO] [stdout] 15 | enum Option<T> {
[INFO] [stdout]    |      ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `Result` is never used
[INFO] [stdout]   --> src/bin/generics/main.rs:20:6
[INFO] [stdout]    |
[INFO] [stdout] 20 | enum Result<T, E> {
[INFO] [stdout]    |      ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `distance_from_origin` is never used
[INFO] [stdout]   --> src/bin/generics/main.rs:32:5
[INFO] [stdout]    |
[INFO] [stdout] 31 | impl Point<f32> {
[INFO] [stdout]    | --------------- method in this implementation
[INFO] [stdout] 32 |     fn distance_from_origin(&self) -> f32 {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `mixup` is never used
[INFO] [stdout]   --> src/bin/generics/main.rs:38:5
[INFO] [stdout]    |
[INFO] [stdout] 37 | impl<T, U> Point2<T, U> {
[INFO] [stdout]    | ----------------------- method in this implementation
[INFO] [stdout] 38 |     fn mixup<V, W>(self, other: Point2<V, W>) -> Point2<T, W> {
[INFO] [stdout]    |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `notify_mult_impl` is never used
[INFO] [stdout]   --> src/bin/generics/main.rs:70:4
[INFO] [stdout]    |
[INFO] [stdout] 70 | fn notify_mult_impl<T: Summary + Minimize>(item: &T) {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `some_function` is never used
[INFO] [stdout]   --> src/bin/generics/main.rs:79:4
[INFO] [stdout]    |
[INFO] [stdout] 79 | fn some_function<T: Display + Debug, U: Clone + Debug>(t: &T, u: &U) -> i32 {5}
[INFO] [stdout]    |    ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `some_function_where_` is never used
[INFO] [stdout]   --> src/bin/generics/main.rs:81:4
[INFO] [stdout]    |
[INFO] [stdout] 81 | fn some_function_where_<T, U>(t: &T, u: &U) -> i32 
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `largest_clone` is never used
[INFO] [stdout]    --> src/bin/generics/main.rs:107:4
[INFO] [stdout]     |
[INFO] [stdout] 107 | fn largest_clone<T: PartialOrd + Clone>(list: &[T]) -> T {
[INFO] [stdout]     |    ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `largest_using_return_ref` is never used
[INFO] [stdout]    --> src/bin/generics/main.rs:118:4
[INFO] [stdout]     |
[INFO] [stdout] 118 | fn largest_using_return_ref<T: PartialOrd>(list: &[T]) -> &T {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Pair` is never constructed
[INFO] [stdout]    --> src/bin/generics/main.rs:130:8
[INFO] [stdout]     |
[INFO] [stdout] 130 | struct Pair<T> {
[INFO] [stdout]     |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]    --> src/bin/generics/main.rs:136:5
[INFO] [stdout]     |
[INFO] [stdout] 135 | impl<T> Pair<T> {
[INFO] [stdout]     | --------------- associated function in this implementation
[INFO] [stdout] 136 |     fn new(x: T, y: T) -> Self {
[INFO] [stdout]     |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `cmp_display` is never used
[INFO] [stdout]    --> src/bin/generics/main.rs:142:5
[INFO] [stdout]     |
[INFO] [stdout] 141 | impl <T: Display + PartialOrd> Pair<T> {
[INFO] [stdout]     | -------------------------------------- method in this implementation
[INFO] [stdout] 142 |     fn cmp_display(&self) { // fn is only implement when generic type of T conform to PartialOrd and Display trait
[INFO] [stdout]     |        ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `content` is never read
[INFO] [stdout]   --> src/bin/generics/traits.rs:31:9
[INFO] [stdout]    |
[INFO] [stdout] 27 | pub struct NewsArticle {
[INFO] [stdout]    |            ----------- field in this struct
[INFO] [stdout] ...
[INFO] [stdout] 31 |     pub content: String,
[INFO] [stdout]    |         ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `reply` and `retweet` are never read
[INFO] [stdout]   --> src/bin/generics/traits.rs:37:9
[INFO] [stdout]    |
[INFO] [stdout] 34 | pub struct Tweet {
[INFO] [stdout]    |            ----- fields in this struct
[INFO] [stdout] ...
[INFO] [stdout] 37 |     pub reply: bool,
[INFO] [stdout]    |         ^^^^^
[INFO] [stdout] 38 |     pub retweet: bool,
[INFO] [stdout]    |         ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait method `summarizeDef` should have a snake case name
[INFO] [stdout]   --> src/bin/generics/traits.rs:14:5
[INFO] [stdout]    |
[INFO] [stdout] 14 |     fn summarizeDef(&self) -> String {
[INFO] [stdout]    |        ^^^^^^^^^^^^ help: convert the identifier to snake case: `summarize_def`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_snake_case)]` (part of `#[warn(nonstandard_style)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `user3`
[INFO] [stdout]   --> src/structs/structs1.rs:18:6
[INFO] [stdout]    |
[INFO] [stdout] 18 |     let user3 = User {
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_user3`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `black`
[INFO] [stdout]   --> src/structs/structs1.rs:26:6
[INFO] [stdout]    |
[INFO] [stdout] 26 |     let black = Color(0, 0, 0);
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_black`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `oirigin`
[INFO] [stdout]   --> src/structs/structs1.rs:27:6
[INFO] [stdout]    |
[INFO] [stdout] 27 |     let oirigin = Point(0, 0, 0);
[INFO] [stdout]    |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_oirigin`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `0`, `1`, and `2` are never read
[INFO] [stdout]   --> src/structs/structs1.rs:24:15
[INFO] [stdout]    |
[INFO] [stdout] 24 |     struct Color(i32, i32, i32);
[INFO] [stdout]    |            ----- ^^^  ^^^  ^^^
[INFO] [stdout]    |            |
[INFO] [stdout]    |            fields in this struct
[INFO] [stdout]    |
[INFO] [stdout]    = help: consider removing these fields
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `0`, `1`, and `2` are never read
[INFO] [stdout]   --> src/structs/structs1.rs:25:15
[INFO] [stdout]    |
[INFO] [stdout] 25 |     struct Point(i32, i32, i32);
[INFO] [stdout]    |            ----- ^^^  ^^^  ^^^
[INFO] [stdout]    |            |
[INFO] [stdout]    |            fields in this struct
[INFO] [stdout]    |
[INFO] [stdout]    = help: consider removing these fields
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `username`, `sign_in_count`, and `active` are never read
[INFO] [stdout]   --> src/structs/structs1.rs:52:2
[INFO] [stdout]    |
[INFO] [stdout] 51 | struct User {
[INFO] [stdout]    |        ---- fields in this struct
[INFO] [stdout] 52 |     username: String,
[INFO] [stdout]    |     ^^^^^^^^
[INFO] [stdout] 53 |     email: String,
[INFO] [stdout] 54 |     sign_in_count: u64,
[INFO] [stdout]    |     ^^^^^^^^^^^^^
[INFO] [stdout] 55 |     active: bool,
[INFO] [stdout]    |     ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `add_two` is never used
[INFO] [stdout]  --> src/bin/testing.rs:6:4
[INFO] [stdout]   |
[INFO] [stdout] 6 | fn add_two(a: i32) -> i32 {
[INFO] [stdout]   |    ^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Rectangle` is never constructed
[INFO] [stdout]   --> src/bin/testing.rs:99:8
[INFO] [stdout]    |
[INFO] [stdout] 99 | struct Rectangle {
[INFO] [stdout]    |        ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v`
[INFO] [stdout]   --> src/enums/enums2.rs:19:6
[INFO] [stdout]    |
[INFO] [stdout] 19 |     let v = value_in_cents(c);
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_v`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `six`
[INFO] [stdout]   --> src/enums/enums2.rs:27:6
[INFO] [stdout]    |
[INFO] [stdout] 27 |     let six = plus_one(five);
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_six`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `none`
[INFO] [stdout]   --> src/enums/enums2.rs:28:6
[INFO] [stdout]    |
[INFO] [stdout] 28 |     let none = plus_one(None);
[INFO] [stdout]    |         ^^^^
[INFO] [stdout]    |
[INFO] [stdout] help: if this is intentional, prefix it with an underscore
[INFO] [stdout]    |
[INFO] [stdout] 28 |     let _none = plus_one(None);
[INFO] [stdout]    |         +
[INFO] [stdout] help: you might have meant to pattern match on the similarly named variant `None`
[INFO] [stdout]    |
[INFO] [stdout] 28 -     let none = plus_one(None);
[INFO] [stdout] 28 +     let std::prelude::v1::None = plus_one(None);
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `count` is assigned to, but never used
[INFO] [stdout]   --> src/enums/enums2.rs:54:10
[INFO] [stdout]    |
[INFO] [stdout] 54 |     let mut count = 0;
[INFO] [stdout]    |             ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: consider using `_count` instead
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `count` is never read
[INFO] [stdout]   --> src/enums/enums2.rs:59:3
[INFO] [stdout]    |
[INFO] [stdout] 59 |         count += 1;
[INFO] [stdout]    |         ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout]    = note: `#[warn(unused_assignments)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variants `Penny` and `Nickel` are never constructed
[INFO] [stdout]  --> src/enums/enums2.rs:4:2
[INFO] [stdout]   |
[INFO] [stdout] 3 | enum Coin {
[INFO] [stdout]   |      ---- variants in this enum
[INFO] [stdout] 4 |     Penny,
[INFO] [stdout]   |     ^^^^^
[INFO] [stdout] 5 |     Nickel,
[INFO] [stdout]   |     ^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]   --> src/ownership.rs:14:6
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let y = x;    // copies x to y
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s2`
[INFO] [stdout]   --> src/ownership.rs:20:7
[INFO] [stdout]    |
[INFO] [stdout] 20 |         let s2 = s1;    // s1 is considered invalid now
[INFO] [stdout]    |             ^^ help: if this is intentional, prefix it with an underscore: `_s2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s1`
[INFO] [stdout]   --> src/ownership.rs:64:6
[INFO] [stdout]    |
[INFO] [stdout] 64 |     let s1 = gives_ownership();
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_s1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s3`
[INFO] [stdout]   --> src/ownership.rs:66:6
[INFO] [stdout]    |
[INFO] [stdout] 66 |     let s3 = takes_and_gives_back(s2);    // takes s2 then gives it back
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_s3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s2`
[INFO] [stdout]   --> src/ownership.rs:70:7
[INFO] [stdout]    |
[INFO] [stdout] 70 |     let (s2, len) = calculate_length(s1);    // rember s1 is moved into function 
[INFO] [stdout]    |          ^^ help: if this is intentional, prefix it with an underscore: `_s2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `len`
[INFO] [stdout]   --> src/ownership.rs:70:11
[INFO] [stdout]    |
[INFO] [stdout] 70 |     let (s2, len) = calculate_length(s1);    // rember s1 is moved into function 
[INFO] [stdout]    |              ^^^ help: if this is intentional, prefix it with an underscore: `_len`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/ownership.rs:74:20
[INFO] [stdout]    |
[INFO] [stdout] 74 | fn take_ownership (s: String) {
[INFO] [stdout]    |                    ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `n`
[INFO] [stdout]   --> src/ownership.rs:78:15
[INFO] [stdout]    |
[INFO] [stdout] 78 | fn makes_copy(n :i32) {
[INFO] [stdout]    |               ^ help: if this is intentional, prefix it with an underscore: `_n`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `guess`
[INFO] [stdout]  --> src/data-types.rs:9:6
[INFO] [stdout]   |
[INFO] [stdout] 9 |     let guess: u32 = "43".parse().expect("this is not a number");    // works:
[INFO] [stdout]   |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_guess`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:12:6
[INFO] [stdout]    |
[INFO] [stdout] 12 |     let x: i8;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:13:6
[INFO] [stdout]    |
[INFO] [stdout] 13 |     let x: u8;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:14:6
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let x: i16;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:15:6
[INFO] [stdout]    |
[INFO] [stdout] 15 |     let x: u16;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:16:6
[INFO] [stdout]    |
[INFO] [stdout] 16 |     let x: i32;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:17:6
[INFO] [stdout]    |
[INFO] [stdout] 17 |     let x: u32;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:18:6
[INFO] [stdout]    |
[INFO] [stdout] 18 |     let x: i64;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:19:6
[INFO] [stdout]    |
[INFO] [stdout] 19 |     let x: u64;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:20:6
[INFO] [stdout]    |
[INFO] [stdout] 20 |     let x: i128;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:21:6
[INFO] [stdout]    |
[INFO] [stdout] 21 |     let x: u128;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:22:6
[INFO] [stdout]    |
[INFO] [stdout] 22 |     let x: isize;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:23:6
[INFO] [stdout]    |
[INFO] [stdout] 23 |     let x: usize;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:26:6
[INFO] [stdout]    |
[INFO] [stdout] 26 |     let x = 2.0;    // defaults to f64
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]   --> src/data-types.rs:27:6
[INFO] [stdout]    |
[INFO] [stdout] 27 |     let y: f32 = 3.0;     // f32
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `t`
[INFO] [stdout]   --> src/data-types.rs:30:6
[INFO] [stdout]    |
[INFO] [stdout] 30 |     let t = true;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_t`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/data-types.rs:31:6
[INFO] [stdout]    |
[INFO] [stdout] 31 |     let f: bool = false;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `c`
[INFO] [stdout]   --> src/data-types.rs:34:6
[INFO] [stdout]    |
[INFO] [stdout] 34 |     let c = 'z';    // char
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_c`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `z`
[INFO] [stdout]   --> src/data-types.rs:37:6
[INFO] [stdout]    |
[INFO] [stdout] 37 |     let z = 'ℤ';    // char
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_z`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `heart_eyed_cat`
[INFO] [stdout]   --> src/data-types.rs:38:6
[INFO] [stdout]    |
[INFO] [stdout] 38 |     let heart_eyed_cat = '😻';    // char
[INFO] [stdout]    |         ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_heart_eyed_cat`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:45:7
[INFO] [stdout]    |
[INFO] [stdout] 45 |     let (x, y, z) = tup;
[INFO] [stdout]    |          ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `z`
[INFO] [stdout]   --> src/data-types.rs:45:13
[INFO] [stdout]    |
[INFO] [stdout] 45 |     let (x, y, z) = tup;
[INFO] [stdout]    |                ^ help: if this is intentional, prefix it with an underscore: `_z`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `five_hundred`
[INFO] [stdout]   --> src/data-types.rs:48:6
[INFO] [stdout]    |
[INFO] [stdout] 48 |     let five_hundred = tup.0;
[INFO] [stdout]    |         ^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_five_hundred`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `six_point_four`
[INFO] [stdout]   --> src/data-types.rs:49:9
[INFO] [stdout]    |
[INFO] [stdout] 49 |     let six_point_four =tup.1;
[INFO] [stdout]    |         ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_six_point_four`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `one`
[INFO] [stdout]   --> src/data-types.rs:50:9
[INFO] [stdout]    |
[INFO] [stdout] 50 |     let one = tup.2;
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_one`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]   --> src/data-types.rs:53:6
[INFO] [stdout]    |
[INFO] [stdout] 53 |     let a = [1, 2, 3, 4, 5];
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]   --> src/data-types.rs:55:6
[INFO] [stdout]    |
[INFO] [stdout] 55 |     let a: [i32; 5] = [1,2,3,4,5];    // an array of 5 i32's
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `fisrt`
[INFO] [stdout]   --> src/data-types.rs:57:6
[INFO] [stdout]    |
[INFO] [stdout] 57 |     let fisrt =a[0];
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_fisrt`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]   --> src/functions.rs:13:6
[INFO] [stdout]    |
[INFO] [stdout] 13 |     let y = 6; // is a statement.
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `len`
[INFO] [stdout]  --> src/references.rs:6:6
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let len = calculate_length(&s1);
[INFO] [stdout]   |         ^^^ help: if this is intentional, prefix it with an underscore: `_len`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r1`
[INFO] [stdout]   --> src/references.rs:22:7
[INFO] [stdout]    |
[INFO] [stdout] 22 |         let r1 = &mut s;
[INFO] [stdout]    |             ^^ help: if this is intentional, prefix it with an underscore: `_r1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r1`
[INFO] [stdout]   --> src/references.rs:29:6
[INFO] [stdout]    |
[INFO] [stdout] 29 |     let r1 = &s; // no problem
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_r1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `r2`
[INFO] [stdout]   --> src/references.rs:30:6
[INFO] [stdout]    |
[INFO] [stdout] 30 |     let r2 = &s; // no problem
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_r2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/references.rs:28:6
[INFO] [stdout]    |
[INFO] [stdout] 28 |     let mut s = String::from("hello");
[INFO] [stdout]    |         ----^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `some_string`
[INFO] [stdout]   --> src/references.rs:61:11
[INFO] [stdout]    |
[INFO] [stdout] 61 | fn change(some_string: &String) {
[INFO] [stdout]    |           ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_some_string`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v`
[INFO] [stdout]  --> src/bin/collections/vectors.rs:6:6
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let v: Vec<i32> = Vec::new();
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_v`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `does_not_exit`
[INFO] [stdout]   --> src/bin/collections/vectors.rs:34:6
[INFO] [stdout]    |
[INFO] [stdout] 34 |     let does_not_exit = v.get(100);    // type: Option<&i32> // this won't
[INFO] [stdout]    |         ^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_does_not_exit`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> src/bin/collections/vectors.rs:44:6
[INFO] [stdout]    |
[INFO] [stdout] 44 |     for i in &v {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `row`
[INFO] [stdout]   --> src/bin/collections/vectors.rs:57:6
[INFO] [stdout]    |
[INFO] [stdout] 57 |     let row = vec![
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_row`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `median` is never read
[INFO] [stdout]    --> src/bin/collections/vectors.rs:103:10
[INFO] [stdout]     |
[INFO] [stdout] 103 |     let mut median: f64 = -1.0;
[INFO] [stdout]     |             ^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout]     = note: `#[warn(unused_assignments)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]  --> src/bin/collections/strings.rs:5:10
[INFO] [stdout]   |
[INFO] [stdout] 5 |     let mut s = String::new();      // type: String
[INFO] [stdout]   |             ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]  --> src/bin/collections/strings.rs:7:6
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let s = data.to_string();      // type: String
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]  --> src/bin/collections/strings.rs:8:6
[INFO] [stdout]   |
[INFO] [stdout] 8 |     let s = String::from("initial contents");
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:11:6
[INFO] [stdout]    |
[INFO] [stdout] 11 |     let hello = String::from("السلام عليكم");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:12:9
[INFO] [stdout]    |
[INFO] [stdout] 12 |     let hello = String::from("Dobrý den");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:13:9
[INFO] [stdout]    |
[INFO] [stdout] 13 |     let hello = String::from("Hello");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:14:9
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let hello = String::from("שָׁלוֹם");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:15:9
[INFO] [stdout]    |
[INFO] [stdout] 15 |     let hello = String::from("नमस्ते");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:16:9
[INFO] [stdout]    |
[INFO] [stdout] 16 |     let hello = String::from("こんにちは");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:17:9
[INFO] [stdout]    |
[INFO] [stdout] 17 |     let hello = String::from("안녕하세요");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:18:9
[INFO] [stdout]    |
[INFO] [stdout] 18 |     let hello = String::from("你好");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:19:9
[INFO] [stdout]    |
[INFO] [stdout] 19 |     let hello = String::from("Olá");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:20:9
[INFO] [stdout]    |
[INFO] [stdout] 20 |     let hello = String::from("Здравствуйте");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:21:9
[INFO] [stdout]    |
[INFO] [stdout] 21 |     let hello = String::from("Hola");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s3`
[INFO] [stdout]   --> src/bin/collections/strings.rs:39:6
[INFO] [stdout]    |
[INFO] [stdout] 39 |     let s3 = s1 + &s2;    // NOTE: s1 has been moved here and can no longer be used
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_s3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/bin/collections/strings.rs:46:9
[INFO] [stdout]    |
[INFO] [stdout] 46 |     let s = format!("{}-{}-{}", s1, s2, s3);
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s1`
[INFO] [stdout]   --> src/bin/collections/strings.rs:50:6
[INFO] [stdout]    |
[INFO] [stdout] 50 |     let s1 = String::from("hello");
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_s1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:53:6
[INFO] [stdout]    |
[INFO] [stdout] 53 |     let hello = String::from("Hola");    // len is 4 each character in UTF-8 is 1 byte
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:54:6
[INFO] [stdout]    |
[INFO] [stdout] 54 |     let hello = String::from("З3дравствуйте");    // len is 24 not 12
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/bin/collections/strings.rs:57:6
[INFO] [stdout]    |
[INFO] [stdout] 57 |     let s = &hello[0..4];    // type: &str (actual bytes)
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `file`
[INFO] [stdout]   --> src/bin/errors.rs:12:6
[INFO] [stdout]    |
[INFO] [stdout] 12 |     let file = match f {
[INFO] [stdout]    |         ^^^^ help: if this is intentional, prefix it with an underscore: `_file`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/bin/errors.rs:24:6
[INFO] [stdout]    |
[INFO] [stdout] 24 |     let f = File::open("hello.txt").unwrap_or_else(|error| {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/bin/errors.rs:36:6
[INFO] [stdout]    |
[INFO] [stdout] 36 |     let f = File::open("hello.txt").unwrap();
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/bin/errors.rs:43:6
[INFO] [stdout]    |
[INFO] [stdout] 43 |     let f =File::open("hello.txt").expect("error message couldn't blah blah...");
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/bin/errors.rs:50:6
[INFO] [stdout]    |
[INFO] [stdout] 50 |         Ok(s) => println!("returned string with data"),
[INFO] [stdout]    |            ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]  --> src/bin/collections/strings.rs:5:6
[INFO] [stdout]   |
[INFO] [stdout] 5 |     let mut s = String::new();      // type: String
[INFO] [stdout]   |         ----^
[INFO] [stdout]   |         |
[INFO] [stdout]   |         help: remove this `mut`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `k2`
[INFO] [stdout]   --> src/bin/collections/hashmaps.rs:70:7
[INFO] [stdout]    |
[INFO] [stdout] 70 |         let k2 = String::from("world");
[INFO] [stdout]    |             ^^ help: if this is intentional, prefix it with an underscore: `_k2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/bin/errors.rs:65:2
[INFO] [stdout]    |
[INFO] [stdout] 65 |     read_username_from_file_oneline("hello.txt");
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 65 |     let _ = read_username_from_file_oneline("hello.txt");
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/bin/collections/vectors.rs:52:7
[INFO] [stdout]    |
[INFO] [stdout] 52 |         Int(i32),
[INFO] [stdout]    |         --- ^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         field in this variant
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 52 -         Int(i32),
[INFO] [stdout] 52 +         Int(()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/bin/collections/vectors.rs:53:9
[INFO] [stdout]    |
[INFO] [stdout] 53 |         Float(f64),
[INFO] [stdout]    |         ----- ^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         field in this variant
[INFO] [stdout]    |
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 53 -         Float(f64),
[INFO] [stdout] 53 +         Float(()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/bin/collections/vectors.rs:54:8
[INFO] [stdout]    |
[INFO] [stdout] 54 |         Text(String),
[INFO] [stdout]    |         ---- ^^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         field in this variant
[INFO] [stdout]    |
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 54 -         Text(String),
[INFO] [stdout] 54 +         Text(()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/bin/collections/vectors.rs:67:9
[INFO] [stdout]    |
[INFO] [stdout] 67 |         Valid(f64)
[INFO] [stdout]    |         ----- ^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         field in this variant
[INFO] [stdout]    |
[INFO] [stdout]    = note: `State` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 67 -         Valid(f64)
[INFO] [stdout] 67 +         Valid(())
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `k2`
[INFO] [stdout]   --> src/bin/collections/hashmaps.rs:70:7
[INFO] [stdout]    |
[INFO] [stdout] 70 |         let k2 = String::from("world");
[INFO] [stdout]    |             ^^ help: if this is intentional, prefix it with an underscore: `_k2`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]  --> src/slices.rs:7:6
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let slice = &s[0..2];
[INFO] [stdout]   |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]  --> src/slices.rs:8:6
[INFO] [stdout]   |
[INFO] [stdout] 8 |     let slice = &s[..2];
[INFO] [stdout]   |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]  --> src/slices.rs:9:6
[INFO] [stdout]   |
[INFO] [stdout] 9 |     let slice = &s[3..s.len()];
[INFO] [stdout]   |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]   --> src/slices.rs:10:6
[INFO] [stdout]    |
[INFO] [stdout] 10 |     let slice = &s[3..];
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `word`
[INFO] [stdout]   --> src/slices.rs:22:7
[INFO] [stdout]    |
[INFO] [stdout] 22 |         let word = first_word_better(&s[..]);
[INFO] [stdout]    |             ^^^^ help: if this is intentional, prefix it with an underscore: `_word`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `word`
[INFO] [stdout]   --> src/slices.rs:23:7
[INFO] [stdout]    |
[INFO] [stdout] 23 |         let word = first_word_better(&string_literal[..]);
[INFO] [stdout]    |             ^^^^ help: if this is intentional, prefix it with an underscore: `_word`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `word`
[INFO] [stdout]   --> src/slices.rs:25:7
[INFO] [stdout]    |
[INFO] [stdout] 25 |         let word = first_word_better(string_literal);
[INFO] [stdout]    |             ^^^^ help: if this is intentional, prefix it with an underscore: `_word`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]  --> src/slices.rs:5:6
[INFO] [stdout]   |
[INFO] [stdout] 5 |     let mut s = String::from("hello world");
[INFO] [stdout]   |         ----^
[INFO] [stdout]   |         |
[INFO] [stdout]   |         help: remove this `mut`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `contents`
[INFO] [stdout]   --> src/main.rs:11:9
[INFO] [stdout]    |
[INFO] [stdout] 11 |     let contents = format!("{}\t{}\n", key, value);
[INFO] [stdout]    |         ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_contents`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]  --> src/bin/collections/strings.rs:5:10
[INFO] [stdout]   |
[INFO] [stdout] 5 |     let mut s = String::new();      // type: String
[INFO] [stdout]   |             ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]  --> src/bin/collections/strings.rs:7:6
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let s = data.to_string();      // type: String
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]  --> src/bin/collections/strings.rs:8:6
[INFO] [stdout]   |
[INFO] [stdout] 8 |     let s = String::from("initial contents");
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:11:6
[INFO] [stdout]    |
[INFO] [stdout] 11 |     let hello = String::from("السلام عليكم");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:12:9
[INFO] [stdout]    |
[INFO] [stdout] 12 |     let hello = String::from("Dobrý den");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:13:9
[INFO] [stdout]    |
[INFO] [stdout] 13 |     let hello = String::from("Hello");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:14:9
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let hello = String::from("שָׁלוֹם");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:15:9
[INFO] [stdout]    |
[INFO] [stdout] 15 |     let hello = String::from("नमस्ते");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:16:9
[INFO] [stdout]    |
[INFO] [stdout] 16 |     let hello = String::from("こんにちは");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:17:9
[INFO] [stdout]    |
[INFO] [stdout] 17 |     let hello = String::from("안녕하세요");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:18:9
[INFO] [stdout]    |
[INFO] [stdout] 18 |     let hello = String::from("你好");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:19:9
[INFO] [stdout]    |
[INFO] [stdout] 19 |     let hello = String::from("Olá");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:20:9
[INFO] [stdout]    |
[INFO] [stdout] 20 |     let hello = String::from("Здравствуйте");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:21:9
[INFO] [stdout]    |
[INFO] [stdout] 21 |     let hello = String::from("Hola");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s3`
[INFO] [stdout]   --> src/bin/collections/strings.rs:39:6
[INFO] [stdout]    |
[INFO] [stdout] 39 |     let s3 = s1 + &s2;    // NOTE: s1 has been moved here and can no longer be used
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_s3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/bin/collections/strings.rs:46:9
[INFO] [stdout]    |
[INFO] [stdout] 46 |     let s = format!("{}-{}-{}", s1, s2, s3);
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s1`
[INFO] [stdout]   --> src/bin/collections/strings.rs:50:6
[INFO] [stdout]    |
[INFO] [stdout] 50 |     let s1 = String::from("hello");
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_s1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:53:6
[INFO] [stdout]    |
[INFO] [stdout] 53 |     let hello = String::from("Hola");    // len is 4 each character in UTF-8 is 1 byte
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:54:6
[INFO] [stdout]    |
[INFO] [stdout] 54 |     let hello = String::from("З3дравствуйте");    // len is 24 not 12
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/bin/collections/strings.rs:57:6
[INFO] [stdout]    |
[INFO] [stdout] 57 |     let s = &hello[0..4];    // type: &str (actual bytes)
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]  --> src/bin/collections/strings.rs:5:6
[INFO] [stdout]   |
[INFO] [stdout] 5 |     let mut s = String::new();      // type: String
[INFO] [stdout]   |         ----^
[INFO] [stdout]   |         |
[INFO] [stdout]   |         help: remove this `mut`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v`
[INFO] [stdout]  --> src/bin/collections/vectors.rs:6:6
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let v: Vec<i32> = Vec::new();
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_v`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `does_not_exit`
[INFO] [stdout]   --> src/bin/collections/vectors.rs:34:6
[INFO] [stdout]    |
[INFO] [stdout] 34 |     let does_not_exit = v.get(100);    // type: Option<&i32> // this won't
[INFO] [stdout]    |         ^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_does_not_exit`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> src/bin/collections/vectors.rs:44:6
[INFO] [stdout]    |
[INFO] [stdout] 44 |     for i in &v {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `row`
[INFO] [stdout]   --> src/bin/collections/vectors.rs:57:6
[INFO] [stdout]    |
[INFO] [stdout] 57 |     let row = vec![
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_row`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `median` is never read
[INFO] [stdout]    --> src/bin/collections/vectors.rs:103:10
[INFO] [stdout]     |
[INFO] [stdout] 103 |     let mut median: f64 = -1.0;
[INFO] [stdout]     |             ^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout]     = note: `#[warn(unused_assignments)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `rect1`
[INFO] [stdout]   --> src/structs/structs2.rs:15:6
[INFO] [stdout]    |
[INFO] [stdout] 15 |     let rect1 = Rectangle {
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_rect1`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `width` and `height` are never read
[INFO] [stdout]  --> src/structs/structs2.rs:4:2
[INFO] [stdout]   |
[INFO] [stdout] 3 | struct Rectangle {
[INFO] [stdout]   |        --------- fields in this struct
[INFO] [stdout] 4 |     width: u32,
[INFO] [stdout]   |     ^^^^^
[INFO] [stdout] 5 |     height: u32,
[INFO] [stdout]   |     ^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `width` and `height` are never read
[INFO] [stdout]   --> src/structs/structs2.rs:10:2
[INFO] [stdout]    |
[INFO] [stdout]  9 | struct RectangleDebug {
[INFO] [stdout]    |        -------------- fields in this struct
[INFO] [stdout] 10 |     width: u32,
[INFO] [stdout]    |     ^^^^^
[INFO] [stdout] 11 |     height: u32
[INFO] [stdout]    |     ^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `RectangleDebug` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `spaces`
[INFO] [stdout]   --> src/variables.rs:28:6
[INFO] [stdout]    |
[INFO] [stdout] 28 |     let spaces = spaces.len();         // type: usize
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_spaces`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `spaces_mut`
[INFO] [stdout]   --> src/variables.rs:30:10
[INFO] [stdout]    |
[INFO] [stdout] 30 |     let mut spaces_mut = "    ";            // type: &str
[INFO] [stdout]    |             ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_spaces_mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/variables.rs:30:6
[INFO] [stdout]    |
[INFO] [stdout] 30 |     let mut spaces_mut = "    ";            // type: &str
[INFO] [stdout]    |         ----^^^^^^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `0`, `1`, `2`, and `3` are never read
[INFO] [stdout]   --> src/enums/enums1.rs:12:5
[INFO] [stdout]    |
[INFO] [stdout] 12 |     V4(u8, u8, u8, u8),
[INFO] [stdout]    |     -- ^^  ^^  ^^  ^^
[INFO] [stdout]    |     |
[INFO] [stdout]    |     fields in this variant
[INFO] [stdout]    |
[INFO] [stdout]    = note: `IpAddrKind2` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: consider changing the fields to be of unit type to suppress this warning while preserving the field numbering, or remove the fields
[INFO] [stdout]    |
[INFO] [stdout] 12 -     V4(u8, u8, u8, u8),
[INFO] [stdout] 12 +     V4((), (), (), ()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/enums/enums1.rs:13:5
[INFO] [stdout]    |
[INFO] [stdout] 13 |     V6(String)
[INFO] [stdout]    |     -- ^^^^^^
[INFO] [stdout]    |     |
[INFO] [stdout]    |     field in this variant
[INFO] [stdout]    |
[INFO] [stdout]    = note: `IpAddrKind2` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 13 -     V6(String)
[INFO] [stdout] 13 +     V6(())
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/enums/enums1.rs:19:8
[INFO] [stdout]    |
[INFO] [stdout] 19 |     Write(String),
[INFO] [stdout]    |     ----- ^^^^^^
[INFO] [stdout]    |     |
[INFO] [stdout]    |     field in this variant
[INFO] [stdout]    |
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 19 -     Write(String),
[INFO] [stdout] 19 +     Write(()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/bin/iterators.rs:93:6
[INFO] [stdout]    |
[INFO] [stdout] 93 |     let x: Vec<_> = v1.iter().map(|x|  x + 1).collect();
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]   --> src/ownership.rs:14:6
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let y = x;    // copies x to y
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s2`
[INFO] [stdout]   --> src/ownership.rs:20:7
[INFO] [stdout]    |
[INFO] [stdout] 20 |         let s2 = s1;    // s1 is considered invalid now
[INFO] [stdout]    |             ^^ help: if this is intentional, prefix it with an underscore: `_s2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s1`
[INFO] [stdout]   --> src/ownership.rs:64:6
[INFO] [stdout]    |
[INFO] [stdout] 64 |     let s1 = gives_ownership();
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_s1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s3`
[INFO] [stdout]   --> src/ownership.rs:66:6
[INFO] [stdout]    |
[INFO] [stdout] 66 |     let s3 = takes_and_gives_back(s2);    // takes s2 then gives it back
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_s3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s2`
[INFO] [stdout]   --> src/ownership.rs:70:7
[INFO] [stdout]    |
[INFO] [stdout] 70 |     let (s2, len) = calculate_length(s1);    // rember s1 is moved into function 
[INFO] [stdout]    |          ^^ help: if this is intentional, prefix it with an underscore: `_s2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `len`
[INFO] [stdout]   --> src/ownership.rs:70:11
[INFO] [stdout]    |
[INFO] [stdout] 70 |     let (s2, len) = calculate_length(s1);    // rember s1 is moved into function 
[INFO] [stdout]    |              ^^^ help: if this is intentional, prefix it with an underscore: `_len`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/ownership.rs:74:20
[INFO] [stdout]    |
[INFO] [stdout] 74 | fn take_ownership (s: String) {
[INFO] [stdout]    |                    ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `n`
[INFO] [stdout]   --> src/ownership.rs:78:15
[INFO] [stdout]    |
[INFO] [stdout] 78 | fn makes_copy(n :i32) {
[INFO] [stdout]    |               ^ help: if this is intentional, prefix it with an underscore: `_n`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]  --> src/slices.rs:7:6
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let slice = &s[0..2];
[INFO] [stdout]   |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]  --> src/slices.rs:8:6
[INFO] [stdout]   |
[INFO] [stdout] 8 |     let slice = &s[..2];
[INFO] [stdout]   |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]  --> src/slices.rs:9:6
[INFO] [stdout]   |
[INFO] [stdout] 9 |     let slice = &s[3..s.len()];
[INFO] [stdout]   |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `slice`
[INFO] [stdout]   --> src/slices.rs:10:6
[INFO] [stdout]    |
[INFO] [stdout] 10 |     let slice = &s[3..];
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `word`
[INFO] [stdout]   --> src/slices.rs:22:7
[INFO] [stdout]    |
[INFO] [stdout] 22 |         let word = first_word_better(&s[..]);
[INFO] [stdout]    |             ^^^^ help: if this is intentional, prefix it with an underscore: `_word`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `word`
[INFO] [stdout]   --> src/slices.rs:23:7
[INFO] [stdout]    |
[INFO] [stdout] 23 |         let word = first_word_better(&string_literal[..]);
[INFO] [stdout]    |             ^^^^ help: if this is intentional, prefix it with an underscore: `_word`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `word`
[INFO] [stdout]   --> src/slices.rs:25:7
[INFO] [stdout]    |
[INFO] [stdout] 25 |         let word = first_word_better(string_literal);
[INFO] [stdout]    |             ^^^^ help: if this is intentional, prefix it with an underscore: `_word`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]  --> src/slices.rs:5:6
[INFO] [stdout]   |
[INFO] [stdout] 5 |     let mut s = String::from("hello world");
[INFO] [stdout]   |         ----^
[INFO] [stdout]   |         |
[INFO] [stdout]   |         help: remove this `mut`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `user3`
[INFO] [stdout]   --> src/structs/structs1.rs:18:6
[INFO] [stdout]    |
[INFO] [stdout] 18 |     let user3 = User {
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_user3`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `black`
[INFO] [stdout]   --> src/structs/structs1.rs:26:6
[INFO] [stdout]    |
[INFO] [stdout] 26 |     let black = Color(0, 0, 0);
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_black`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `oirigin`
[INFO] [stdout]   --> src/structs/structs1.rs:27:6
[INFO] [stdout]    |
[INFO] [stdout] 27 |     let oirigin = Point(0, 0, 0);
[INFO] [stdout]    |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_oirigin`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `username`, `sign_in_count`, and `active` are never read
[INFO] [stdout]   --> src/structs/structs1.rs:52:2
[INFO] [stdout]    |
[INFO] [stdout] 51 | struct User {
[INFO] [stdout]    |        ---- fields in this struct
[INFO] [stdout] 52 |     username: String,
[INFO] [stdout]    |     ^^^^^^^^
[INFO] [stdout] 53 |     email: String,
[INFO] [stdout] 54 |     sign_in_count: u64,
[INFO] [stdout]    |     ^^^^^^^^^^^^^
[INFO] [stdout] 55 |     active: bool,
[INFO] [stdout]    |     ^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `contents`
[INFO] [stdout]   --> src/main.rs:11:9
[INFO] [stdout]    |
[INFO] [stdout] 11 |     let contents = format!("{}\t{}\n", key, value);
[INFO] [stdout]    |         ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_contents`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]   --> src/functions.rs:13:6
[INFO] [stdout]    |
[INFO] [stdout] 13 |     let y = 6; // is a statement.
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `k2`
[INFO] [stdout]   --> src/bin/collections/hashmaps.rs:70:7
[INFO] [stdout]    |
[INFO] [stdout] 70 |         let k2 = String::from("world");
[INFO] [stdout]    |             ^^ help: if this is intentional, prefix it with an underscore: `_k2`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `spaces`
[INFO] [stdout]   --> src/variables.rs:28:6
[INFO] [stdout]    |
[INFO] [stdout] 28 |     let spaces = spaces.len();         // type: usize
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_spaces`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `spaces_mut`
[INFO] [stdout]   --> src/variables.rs:30:10
[INFO] [stdout]    |
[INFO] [stdout] 30 |     let mut spaces_mut = "    ";            // type: &str
[INFO] [stdout]    |             ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_spaces_mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/variables.rs:30:6
[INFO] [stdout]    |
[INFO] [stdout] 30 |     let mut spaces_mut = "    ";            // type: &str
[INFO] [stdout]    |         ----^^^^^^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `guess`
[INFO] [stdout]  --> src/data-types.rs:9:6
[INFO] [stdout]   |
[INFO] [stdout] 9 |     let guess: u32 = "43".parse().expect("this is not a number");    // works:
[INFO] [stdout]   |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_guess`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:12:6
[INFO] [stdout]    |
[INFO] [stdout] 12 |     let x: i8;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:13:6
[INFO] [stdout]    |
[INFO] [stdout] 13 |     let x: u8;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:14:6
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let x: i16;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:15:6
[INFO] [stdout]    |
[INFO] [stdout] 15 |     let x: u16;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:16:6
[INFO] [stdout]    |
[INFO] [stdout] 16 |     let x: i32;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:17:6
[INFO] [stdout]    |
[INFO] [stdout] 17 |     let x: u32;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:18:6
[INFO] [stdout]    |
[INFO] [stdout] 18 |     let x: i64;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:19:6
[INFO] [stdout]    |
[INFO] [stdout] 19 |     let x: u64;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:20:6
[INFO] [stdout]    |
[INFO] [stdout] 20 |     let x: i128;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:21:6
[INFO] [stdout]    |
[INFO] [stdout] 21 |     let x: u128;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:22:6
[INFO] [stdout]    |
[INFO] [stdout] 22 |     let x: isize;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:23:6
[INFO] [stdout]    |
[INFO] [stdout] 23 |     let x: usize;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:26:6
[INFO] [stdout]    |
[INFO] [stdout] 26 |     let x = 2.0;    // defaults to f64
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]   --> src/data-types.rs:27:6
[INFO] [stdout]    |
[INFO] [stdout] 27 |     let y: f32 = 3.0;     // f32
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `t`
[INFO] [stdout]   --> src/data-types.rs:30:6
[INFO] [stdout]    |
[INFO] [stdout] 30 |     let t = true;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_t`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/data-types.rs:31:6
[INFO] [stdout]    |
[INFO] [stdout] 31 |     let f: bool = false;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `c`
[INFO] [stdout]   --> src/data-types.rs:34:6
[INFO] [stdout]    |
[INFO] [stdout] 34 |     let c = 'z';    // char
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_c`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `z`
[INFO] [stdout]   --> src/data-types.rs:37:6
[INFO] [stdout]    |
[INFO] [stdout] 37 |     let z = 'ℤ';    // char
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_z`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `heart_eyed_cat`
[INFO] [stdout]   --> src/data-types.rs:38:6
[INFO] [stdout]    |
[INFO] [stdout] 38 |     let heart_eyed_cat = '😻';    // char
[INFO] [stdout]    |         ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_heart_eyed_cat`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/data-types.rs:45:7
[INFO] [stdout]    |
[INFO] [stdout] 45 |     let (x, y, z) = tup;
[INFO] [stdout]    |          ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `z`
[INFO] [stdout]   --> src/data-types.rs:45:13
[INFO] [stdout]    |
[INFO] [stdout] 45 |     let (x, y, z) = tup;
[INFO] [stdout]    |                ^ help: if this is intentional, prefix it with an underscore: `_z`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `five_hundred`
[INFO] [stdout]   --> src/data-types.rs:48:6
[INFO] [stdout]    |
[INFO] [stdout] 48 |     let five_hundred = tup.0;
[INFO] [stdout]    |         ^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_five_hundred`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `six_point_four`
[INFO] [stdout]   --> src/data-types.rs:49:9
[INFO] [stdout]    |
[INFO] [stdout] 49 |     let six_point_four =tup.1;
[INFO] [stdout]    |         ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_six_point_four`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `one`
[INFO] [stdout]   --> src/data-types.rs:50:9
[INFO] [stdout]    |
[INFO] [stdout] 50 |     let one = tup.2;
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_one`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]   --> src/data-types.rs:53:6
[INFO] [stdout]    |
[INFO] [stdout] 53 |     let a = [1, 2, 3, 4, 5];
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]   --> src/data-types.rs:55:6
[INFO] [stdout]    |
[INFO] [stdout] 55 |     let a: [i32; 5] = [1,2,3,4,5];    // an array of 5 i32's
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `fisrt`
[INFO] [stdout]   --> src/data-types.rs:57:6
[INFO] [stdout]    |
[INFO] [stdout] 57 |     let fisrt =a[0];
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_fisrt`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `file`
[INFO] [stdout]   --> src/bin/errors.rs:12:6
[INFO] [stdout]    |
[INFO] [stdout] 12 |     let file = match f {
[INFO] [stdout]    |         ^^^^ help: if this is intentional, prefix it with an underscore: `_file`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/bin/errors.rs:24:6
[INFO] [stdout]    |
[INFO] [stdout] 24 |     let f = File::open("hello.txt").unwrap_or_else(|error| {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/bin/errors.rs:36:6
[INFO] [stdout]    |
[INFO] [stdout] 36 |     let f = File::open("hello.txt").unwrap();
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/bin/errors.rs:43:6
[INFO] [stdout]    |
[INFO] [stdout] 43 |     let f =File::open("hello.txt").expect("error message couldn't blah blah...");
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/bin/errors.rs:50:6
[INFO] [stdout]    |
[INFO] [stdout] 50 |         Ok(s) => println!("returned string with data"),
[INFO] [stdout]    |            ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/bin/errors.rs:65:2
[INFO] [stdout]    |
[INFO] [stdout] 65 |     read_username_from_file_oneline("hello.txt");
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 65 |     let _ = read_username_from_file_oneline("hello.txt");
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]  --> src/bin/collections/strings.rs:5:10
[INFO] [stdout]   |
[INFO] [stdout] 5 |     let mut s = String::new();      // type: String
[INFO] [stdout]   |             ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]  --> src/bin/collections/strings.rs:7:6
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let s = data.to_string();      // type: String
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]  --> src/bin/collections/strings.rs:8:6
[INFO] [stdout]   |
[INFO] [stdout] 8 |     let s = String::from("initial contents");
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:11:6
[INFO] [stdout]    |
[INFO] [stdout] 11 |     let hello = String::from("السلام عليكم");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:12:9
[INFO] [stdout]    |
[INFO] [stdout] 12 |     let hello = String::from("Dobrý den");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:13:9
[INFO] [stdout]    |
[INFO] [stdout] 13 |     let hello = String::from("Hello");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:14:9
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let hello = String::from("שָׁלוֹם");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:15:9
[INFO] [stdout]    |
[INFO] [stdout] 15 |     let hello = String::from("नमस्ते");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:16:9
[INFO] [stdout]    |
[INFO] [stdout] 16 |     let hello = String::from("こんにちは");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:17:9
[INFO] [stdout]    |
[INFO] [stdout] 17 |     let hello = String::from("안녕하세요");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:18:9
[INFO] [stdout]    |
[INFO] [stdout] 18 |     let hello = String::from("你好");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:19:9
[INFO] [stdout]    |
[INFO] [stdout] 19 |     let hello = String::from("Olá");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:20:9
[INFO] [stdout]    |
[INFO] [stdout] 20 |     let hello = String::from("Здравствуйте");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:21:9
[INFO] [stdout]    |
[INFO] [stdout] 21 |     let hello = String::from("Hola");
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s3`
[INFO] [stdout]   --> src/bin/collections/strings.rs:39:6
[INFO] [stdout]    |
[INFO] [stdout] 39 |     let s3 = s1 + &s2;    // NOTE: s1 has been moved here and can no longer be used
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_s3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/bin/collections/strings.rs:46:9
[INFO] [stdout]    |
[INFO] [stdout] 46 |     let s = format!("{}-{}-{}", s1, s2, s3);
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s1`
[INFO] [stdout]   --> src/bin/collections/strings.rs:50:6
[INFO] [stdout]    |
[INFO] [stdout] 50 |     let s1 = String::from("hello");
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_s1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:53:6
[INFO] [stdout]    |
[INFO] [stdout] 53 |     let hello = String::from("Hola");    // len is 4 each character in UTF-8 is 1 byte
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/collections/strings.rs:54:6
[INFO] [stdout]    |
[INFO] [stdout] 54 |     let hello = String::from("З3дравствуйте");    // len is 24 not 12
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_hello`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]   --> src/bin/collections/strings.rs:57:6
[INFO] [stdout]    |
[INFO] [stdout] 57 |     let s = &hello[0..4];    // type: &str (actual bytes)
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]  --> src/bin/collections/strings.rs:5:6
[INFO] [stdout]   |
[INFO] [stdout] 5 |     let mut s = String::new();      // type: String
[INFO] [stdout]   |         ----^
[INFO] [stdout]   |         |
[INFO] [stdout]   |         help: remove this `mut`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/bin/iterators.rs:93:6
[INFO] [stdout]    |
[INFO] [stdout] 93 |     let x: Vec<_> = v1.iter().map(|x|  x + 1).collect();
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Shoe` is never constructed
[INFO] [stdout]  --> src/bin/iterators.rs:5:8
[INFO] [stdout]   |
[INFO] [stdout] 5 | struct Shoe {
[INFO] [stdout]   |        ^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `shoes_in_size` is never used
[INFO] [stdout]   --> src/bin/iterators.rs:10:4
[INFO] [stdout]    |
[INFO] [stdout] 10 | fn shoes_in_size(shoes: Vec<Shoe>, shoe_size: u32) -> Vec<Shoe> {
[INFO] [stdout]    |    ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v`
[INFO] [stdout]   --> src/enums/enums2.rs:19:6
[INFO] [stdout]    |
[INFO] [stdout] 19 |     let v = value_in_cents(c);
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_v`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `six`
[INFO] [stdout]   --> src/enums/enums2.rs:27:6
[INFO] [stdout]    |
[INFO] [stdout] 27 |     let six = plus_one(five);
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_six`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `none`
[INFO] [stdout]   --> src/enums/enums2.rs:28:6
[INFO] [stdout]    |
[INFO] [stdout] 28 |     let none = plus_one(None);
[INFO] [stdout]    |         ^^^^
[INFO] [stdout]    |
[INFO] [stdout] help: if this is intentional, prefix it with an underscore
[INFO] [stdout]    |
[INFO] [stdout] 28 |     let _none = plus_one(None);
[INFO] [stdout]    |         +
[INFO] [stdout] help: you might have meant to pattern match on the similarly named variant `None`
[INFO] [stdout]    |
[INFO] [stdout] 28 -     let none = plus_one(None);
[INFO] [stdout] 28 +     let std::prelude::v1::None = plus_one(None);
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `count` is assigned to, but never used
[INFO] [stdout]   --> src/enums/enums2.rs:54:10
[INFO] [stdout]    |
[INFO] [stdout] 54 |     let mut count = 0;
[INFO] [stdout]    |             ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: consider using `_count` instead
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `count` is never read
[INFO] [stdout]   --> src/enums/enums2.rs:59:3
[INFO] [stdout]    |
[INFO] [stdout] 59 |         count += 1;
[INFO] [stdout]    |         ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout]    = note: `#[warn(unused_assignments)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variants `Penny` and `Nickel` are never constructed
[INFO] [stdout]  --> src/enums/enums2.rs:4:2
[INFO] [stdout]   |
[INFO] [stdout] 3 | enum Coin {
[INFO] [stdout]   |      ---- variants in this enum
[INFO] [stdout] 4 |     Penny,
[INFO] [stdout]   |     ^^^^^
[INFO] [stdout] 5 |     Nickel,
[INFO] [stdout]   |     ^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `c1`
[INFO] [stdout]   --> src/lib.rs:87:13
[INFO] [stdout]    |
[INFO] [stdout] 87 |     pub fn mix(c1: PrimaryColor, c2: PrimaryColor) -> SecondaryColor {
[INFO] [stdout]    |                ^^ help: if this is intentional, prefix it with an underscore: `_c1`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `c2`
[INFO] [stdout]   --> src/lib.rs:87:31
[INFO] [stdout]    |
[INFO] [stdout] 87 |     pub fn mix(c1: PrimaryColor, c2: PrimaryColor) -> SecondaryColor {
[INFO] [stdout]    |                                  ^^ help: if this is intentional, prefix it with an underscore: `_c2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `t`
[INFO] [stdout]   --> src/bin/generics/main.rs:79:56
[INFO] [stdout]    |
[INFO] [stdout] 79 | fn some_function<T: Display + Debug, U: Clone + Debug>(t: &T, u: &U) -> i32 {5}
[INFO] [stdout]    |                                                        ^ help: if this is intentional, prefix it with an underscore: `_t`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `u`
[INFO] [stdout]   --> src/bin/generics/main.rs:79:63
[INFO] [stdout]    |
[INFO] [stdout] 79 | fn some_function<T: Display + Debug, U: Clone + Debug>(t: &T, u: &U) -> i32 {5}
[INFO] [stdout]    |                                                               ^ help: if this is intentional, prefix it with an underscore: `_u`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `t`
[INFO] [stdout]   --> src/bin/generics/main.rs:81:31
[INFO] [stdout]    |
[INFO] [stdout] 81 | fn some_function_where_<T, U>(t: &T, u: &U) -> i32 
[INFO] [stdout]    |                               ^ help: if this is intentional, prefix it with an underscore: `_t`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `u`
[INFO] [stdout]   --> src/bin/generics/main.rs:81:38
[INFO] [stdout]    |
[INFO] [stdout] 81 | fn some_function_where_<T, U>(t: &T, u: &U) -> i32 
[INFO] [stdout]    |                                      ^ help: if this is intentional, prefix it with an underscore: `_u`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `integer`
[INFO] [stdout]    --> src/bin/generics/main.rs:170:6
[INFO] [stdout]     |
[INFO] [stdout] 170 |     let integer =Point {x: 32, y: 23};
[INFO] [stdout]     |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_integer`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `intfloat`
[INFO] [stdout]    --> src/bin/generics/main.rs:173:6
[INFO] [stdout]     |
[INFO] [stdout] 173 |     let intfloat = Point2 {x: 3.2, y: 32};
[INFO] [stdout]     |         ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_intfloat`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `new_tweet`
[INFO] [stdout]    --> src/bin/generics/main.rs:212:6
[INFO] [stdout]     |
[INFO] [stdout] 212 |     let new_tweet = return_summarizable();
[INFO] [stdout]     |         ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_new_tweet`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `y` is never read
[INFO] [stdout]  --> src/bin/generics/main.rs:7:2
[INFO] [stdout]   |
[INFO] [stdout] 5 | struct Point<T> {
[INFO] [stdout]   |        ----- field in this struct
[INFO] [stdout] 6 |     x: T,
[INFO] [stdout] 7 |     y: T,
[INFO] [stdout]   |     ^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `x` and `y` are never read
[INFO] [stdout]   --> src/bin/generics/main.rs:11:5
[INFO] [stdout]    |
[INFO] [stdout] 10 | struct Point2<T, U> {
[INFO] [stdout]    |        ------ fields in this struct
[INFO] [stdout] 11 |     x: T,
[INFO] [stdout]    |     ^
[INFO] [stdout] 12 |     y: U,
[INFO] [stdout]    |     ^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `Option` is never used
[INFO] [stdout]   --> src/bin/generics/main.rs:15:6
[INFO] [stdout]    |
[INFO] [stdout] 15 | enum Option<T> {
[INFO] [stdout]    |      ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `Result` is never used
[INFO] [stdout]   --> src/bin/generics/main.rs:20:6
[INFO] [stdout]    |
[INFO] [stdout] 20 | enum Result<T, E> {
[INFO] [stdout]    |      ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `distance_from_origin` is never used
[INFO] [stdout]   --> src/bin/generics/main.rs:32:5
[INFO] [stdout]    |
[INFO] [stdout] 31 | impl Point<f32> {
[INFO] [stdout]    | --------------- method in this implementation
[INFO] [stdout] 32 |     fn distance_from_origin(&self) -> f32 {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `mixup` is never used
[INFO] [stdout]   --> src/bin/generics/main.rs:38:5
[INFO] [stdout]    |
[INFO] [stdout] 37 | impl<T, U> Point2<T, U> {
[INFO] [stdout]    | ----------------------- method in this implementation
[INFO] [stdout] 38 |     fn mixup<V, W>(self, other: Point2<V, W>) -> Point2<T, W> {
[INFO] [stdout]    |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `notify_mult_impl` is never used
[INFO] [stdout]   --> src/bin/generics/main.rs:70:4
[INFO] [stdout]    |
[INFO] [stdout] 70 | fn notify_mult_impl<T: Summary + Minimize>(item: &T) {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `some_function` is never used
[INFO] [stdout]   --> src/bin/generics/main.rs:79:4
[INFO] [stdout]    |
[INFO] [stdout] 79 | fn some_function<T: Display + Debug, U: Clone + Debug>(t: &T, u: &U) -> i32 {5}
[INFO] [stdout]    |    ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `some_function_where_` is never used
[INFO] [stdout]   --> src/bin/generics/main.rs:81:4
[INFO] [stdout]    |
[INFO] [stdout] 81 | fn some_function_where_<T, U>(t: &T, u: &U) -> i32 
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `largest_clone` is never used
[INFO] [stdout]    --> src/bin/generics/main.rs:107:4
[INFO] [stdout]     |
[INFO] [stdout] 107 | fn largest_clone<T: PartialOrd + Clone>(list: &[T]) -> T {
[INFO] [stdout]     |    ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `largest_using_return_ref` is never used
[INFO] [stdout]    --> src/bin/generics/main.rs:118:4
[INFO] [stdout]     |
[INFO] [stdout] 118 | fn largest_using_return_ref<T: PartialOrd>(list: &[T]) -> &T {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Pair` is never constructed
[INFO] [stdout]    --> src/bin/generics/main.rs:130:8
[INFO] [stdout]     |
[INFO] [stdout] 130 | struct Pair<T> {
[INFO] [stdout]     |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]    --> src/bin/generics/main.rs:136:5
[INFO] [stdout]     |
[INFO] [stdout] 135 | impl<T> Pair<T> {
[INFO] [stdout]     | --------------- associated function in this implementation
[INFO] [stdout] 136 |     fn new(x: T, y: T) -> Self {
[INFO] [stdout]     |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `cmp_display` is never used
[INFO] [stdout]    --> src/bin/generics/main.rs:142:5
[INFO] [stdout]     |
[INFO] [stdout] 141 | impl <T: Display + PartialOrd> Pair<T> {
[INFO] [stdout]     | -------------------------------------- method in this implementation
[INFO] [stdout] 142 |     fn cmp_display(&self) { // fn is only implement when generic type of T conform to PartialOrd and Display trait
[INFO] [stdout]     |        ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `content` is never read
[INFO] [stdout]   --> src/bin/generics/traits.rs:31:9
[INFO] [stdout]    |
[INFO] [stdout] 27 | pub struct NewsArticle {
[INFO] [stdout]    |            ----------- field in this struct
[INFO] [stdout] ...
[INFO] [stdout] 31 |     pub content: String,
[INFO] [stdout]    |         ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `reply` and `retweet` are never read
[INFO] [stdout]   --> src/bin/generics/traits.rs:37:9
[INFO] [stdout]    |
[INFO] [stdout] 34 | pub struct Tweet {
[INFO] [stdout]    |            ----- fields in this struct
[INFO] [stdout] ...
[INFO] [stdout] 37 |     pub reply: bool,
[INFO] [stdout]    |         ^^^^^
[INFO] [stdout] 38 |     pub retweet: bool,
[INFO] [stdout]    |         ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait method `summarizeDef` should have a snake case name
[INFO] [stdout]   --> src/bin/generics/traits.rs:14:5
[INFO] [stdout]    |
[INFO] [stdout] 14 |     fn summarizeDef(&self) -> String {
[INFO] [stdout]    |        ^^^^^^^^^^^^ help: convert the identifier to snake case: `summarize_def`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_snake_case)]` (part of `#[warn(nonstandard_style)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 2.80s
[INFO] running `Command { std: "docker" "inspect" "9eeb876ee868984d3906b2bb1f9c96211521a11bade95d16b2c480b37dc9a33d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9eeb876ee868984d3906b2bb1f9c96211521a11bade95d16b2c480b37dc9a33d", kill_on_drop: false }`
[INFO] [stdout] 9eeb876ee868984d3906b2bb1f9c96211521a11bade95d16b2c480b37dc9a33d
