[INFO] cloning repository https://github.com/Hermitter/rust-book-2018-notes
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Hermitter/rust-book-2018-notes" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FHermitter%2Frust-book-2018-notes", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FHermitter%2Frust-book-2018-notes'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] fcfe4313c342ffaac8443ccb84403c37e23cc419
[INFO] checking Hermitter/rust-book-2018-notes against beta-2020-07-24 for pr-75494-beta
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FHermitter%2Frust-book-2018-notes" "/workspace/builds/worker-13/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-13/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Hermitter/rust-book-2018-notes on toolchain beta-2020-07-24
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-07-24" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/Hermitter/rust-book-2018-notes
[INFO] finished tweaking git repo https://github.com/Hermitter/rust-book-2018-notes
[INFO] tweaked toml for git repo https://github.com/Hermitter/rust-book-2018-notes written to /workspace/builds/worker-13/source/Cargo.toml
[INFO] crate git repo https://github.com/Hermitter/rust-book-2018-notes already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-07-24" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/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" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-07-24" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 707a957579fb2c66fe88e285ffb6bb97991a1f0a0c8bc4af8edccac49f9dae66
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "707a957579fb2c66fe88e285ffb6bb97991a1f0a0c8bc4af8edccac49f9dae66", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "707a957579fb2c66fe88e285ffb6bb97991a1f0a0c8bc4af8edccac49f9dae66", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "707a957579fb2c66fe88e285ffb6bb97991a1f0a0c8bc4af8edccac49f9dae66", kill_on_drop: false }`
[INFO] [stdout] 707a957579fb2c66fe88e285ffb6bb97991a1f0a0c8bc4af8edccac49f9dae66
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/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" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-07-24" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 4f1d7f08a6b2095e18e3efaa152257673933c1296a8d2828a16f8f40a10fde4b
[INFO] running `Command { std: "docker" "start" "-a" "4f1d7f08a6b2095e18e3efaa152257673933c1296a8d2828a16f8f40a10fde4b", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.65
[INFO] [stderr]     Checking rand v0.4.6
[INFO] [stderr]     Checking rand v0.3.23
[INFO] [stderr]     Checking book v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unreachable statement
[INFO] [stdout]   --> src/bin/ch9_error_handling.rs:13:5
[INFO] [stdout]    |
[INFO] [stdout] 10 |     panic!();
[INFO] [stdout]    |     --------- any code following this expression is unreachable
[INFO] [stdout] ...
[INFO] [stdout] 13 |     panic!("I blame Jim for this error.");
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ unreachable statement
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unreachable_code)]` on by default
[INFO] [stdout]    = note: this warning originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unreachable statement
[INFO] [stdout]   --> src/bin/ch9_error_handling.rs:13:5
[INFO] [stdout]    |
[INFO] [stdout] 10 |     panic!();
[INFO] [stdout]    |     --------- any code following this expression is unreachable
[INFO] [stdout] ...
[INFO] [stdout] 13 |     panic!("I blame Jim for this error.");
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ unreachable statement
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unreachable_code)]` on by default
[INFO] [stdout]    = note: this warning originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant `ice_cream` should have an upper camel case name
[INFO] [stdout]   --> src/bin/ch7_modules/main.rs:85:9
[INFO] [stdout]    |
[INFO] [stdout] 85 |         ice_cream,
[INFO] [stdout]    |         ^^^^^^^^^ help: convert the identifier to upper camel case: `IceCream`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_camel_case_types)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant `cake` should have an upper camel case name
[INFO] [stdout]   --> src/bin/ch7_modules/main.rs:86:9
[INFO] [stdout]    |
[INFO] [stdout] 86 |         cake,
[INFO] [stdout]    |         ^^^^ help: convert the identifier to upper camel case (notice the capitalization): `Cake`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `array`, `borrow`, `cmp::Ordering`
[INFO] [stdout]    --> src/bin/ch7_modules/main.rs:119:11
[INFO] [stdout]     |
[INFO] [stdout] 119 | use std::{array, borrow, cmp::Ordering};
[INFO] [stdout]     |           ^^^^^  ^^^^^^  ^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `Write`, `self`
[INFO] [stdout]    --> src/bin/ch7_modules/main.rs:122:15
[INFO] [stdout]     |
[INFO] [stdout] 122 | use std::io::{self, Write}; // imports io & Write
[INFO] [stdout]     |               ^^^^  ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::collections::*`
[INFO] [stdout]    --> src/bin/ch7_modules/main.rs:125:5
[INFO] [stdout]     |
[INFO] [stdout] 125 | use std::collections::*;
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `new_person`
[INFO] [stdout]   --> src/bin/ch5_structs.rs:39:9
[INFO] [stdout]    |
[INFO] [stdout] 39 |     let new_person = build_user("t@gmail.com".to_string(), "tim".to_string());
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_new_person`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `person_copy`
[INFO] [stdout]   --> src/bin/ch5_structs.rs:53:9
[INFO] [stdout]    |
[INFO] [stdout] 53 |     let mut person_copy = User {
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_person_copy`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `rect3`
[INFO] [stdout]    --> src/bin/ch5_structs.rs:139:9
[INFO] [stdout]     |
[INFO] [stdout] 139 |     let rect3 = Rectanglee::new_rect(12, 15);
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_rect3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `panic`
[INFO] [stdout]  --> src/bin/ch9_error_handling.rs:6:4
[INFO] [stdout]   |
[INFO] [stdout] 6 | fn panic() {
[INFO] [stdout]   |    ^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `return_a_result_simpler`
[INFO] [stdout]   --> src/bin/ch9_error_handling.rs:72:8
[INFO] [stdout]    |
[INFO] [stdout] 72 |     fn return_a_result_simpler() -> Result<String, io::Error> {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::thread`
[INFO] [stdout]  --> src/bin/ch13_functional_language_features/closures.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::thread;
[INFO] [stdout]   |     ^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::time::Duration`
[INFO] [stdout]  --> src/bin/ch13_functional_language_features/closures.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use std::time::Duration;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/bin/ch5_structs.rs:53:9
[INFO] [stdout]    |
[INFO] [stdout] 53 |     let mut person_copy = User {
[INFO] [stdout]    |         ----^^^^^^^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `panic`
[INFO] [stdout]  --> src/bin/ch9_error_handling.rs:6:4
[INFO] [stdout]   |
[INFO] [stdout] 6 | fn panic() {
[INFO] [stdout]   |    ^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `test_even`
[INFO] [stdout]   --> src/bin/ch11_automated_tests.rs:14:4
[INFO] [stdout]    |
[INFO] [stdout] 14 | fn test_even(x: i32, y: i32) -> bool {
[INFO] [stdout]    |    ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `new_person`
[INFO] [stdout]   --> src/bin/ch5_structs.rs:39:9
[INFO] [stdout]    |
[INFO] [stdout] 39 |     let new_person = build_user("t@gmail.com".to_string(), "tim".to_string());
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_new_person`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]   --> src/bin/ch3_common_concepts.rs:22:9
[INFO] [stdout]    |
[INFO] [stdout] 22 |     let a = [1, 2, 3, 4, 5];
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `return_a_result_simpler`
[INFO] [stdout]   --> src/bin/ch9_error_handling.rs:72:8
[INFO] [stdout]    |
[INFO] [stdout] 72 |     fn return_a_result_simpler() -> Result<String, io::Error> {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]   --> src/bin/ch3_common_concepts.rs:23:9
[INFO] [stdout]    |
[INFO] [stdout] 23 |     let a: [i32; 5] = [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/bin/ch3_common_concepts.rs:24:9
[INFO] [stdout]    |
[INFO] [stdout] 24 |     let a = [3; 5]; //  let a = [3, 3, 3, 3, 3];
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]    --> src/bin/ch7_modules/main.rs:114:9
[INFO] [stdout]     |
[INFO] [stdout] 114 |     let y: HashMap<i32, i32> = HashMap::new();
[INFO] [stdout]     |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/bin/ch3_common_concepts.rs:29:9
[INFO] [stdout]    |
[INFO] [stdout] 29 |     let x = returns_in_functions(5);
[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/bin/ch3_common_concepts.rs:32:9
[INFO] [stdout]    |
[INFO] [stdout] 32 |     let x = 4;
[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/bin/ch3_common_concepts.rs:35:9
[INFO] [stdout]    |
[INFO] [stdout] 35 |     let y = {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `number`
[INFO] [stdout]   --> src/bin/ch3_common_concepts.rs:51:9
[INFO] [stdout]    |
[INFO] [stdout] 51 |     let number = if condition { 5 } else { 6 };
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_number`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v`
[INFO] [stdout]   --> src/bin/ch8_common_collections.rs:10:9
[INFO] [stdout]    |
[INFO] [stdout] 10 |     let mut 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)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v`
[INFO] [stdout]   --> src/bin/ch8_common_collections.rs:25:13
[INFO] [stdout]    |
[INFO] [stdout] 25 |         let v = vec![1, 2, 3, 4];
[INFO] [stdout]    |             ^ help: if this is intentional, prefix it with an underscore: `_v`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `val`
[INFO] [stdout]   --> src/bin/ch8_common_collections.rs:29:9
[INFO] [stdout]    |
[INFO] [stdout] 29 |     let val: &i32 = &v[2];
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_val`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `string`
[INFO] [stdout]   --> src/bin/ch8_common_collections.rs:87:9
[INFO] [stdout]    |
[INFO] [stdout] 87 |     let mut string = String::new();
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_string`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `string2`
[INFO] [stdout]   --> src/bin/ch8_common_collections.rs:88:9
[INFO] [stdout]    |
[INFO] [stdout] 88 |     let string2 = String::from("hello!");
[INFO] [stdout]    |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_string2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `string_example`
[INFO] [stdout]   --> src/bin/ch8_common_collections.rs:92:9
[INFO] [stdout]    |
[INFO] [stdout] 92 |     let string_example = str_example.to_string();
[INFO] [stdout]    |         ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_string_example`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/ch8_common_collections.rs:95:9
[INFO] [stdout]    |
[INFO] [stdout] 95 |     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: `person_copy`
[INFO] [stdout]   --> src/bin/ch5_structs.rs:53:9
[INFO] [stdout]    |
[INFO] [stdout] 53 |     let mut person_copy = User {
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_person_copy`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `rect3`
[INFO] [stdout]    --> src/bin/ch5_structs.rs:139:9
[INFO] [stdout]     |
[INFO] [stdout] 139 |     let rect3 = Rectanglee::new_rect(12, 15);
[INFO] [stdout]     |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_rect3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/bin/ch5_structs.rs:53:9
[INFO] [stdout]    |
[INFO] [stdout] 53 |     let mut person_copy = User {
[INFO] [stdout]    |         ----^^^^^^^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/ch8_common_collections.rs:96:9
[INFO] [stdout]    |
[INFO] [stdout] 96 |     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: `x`
[INFO] [stdout]    --> src/bin/ch7_modules/main.rs:115:9
[INFO] [stdout]     |
[INFO] [stdout] 115 |     let x = HashMap::<i32, i32>::new(); // turbo fish ::<> will be covered in the future
[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/bin/ch7_modules/main.rs:131:9
[INFO] [stdout]     |
[INFO] [stdout] 131 |     let x = some_file::HashMap::<i32, i32>::new();
[INFO] [stdout]     |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `sign_in_count`
[INFO] [stdout]  --> src/bin/ch5_structs.rs:6:9
[INFO] [stdout]   |
[INFO] [stdout] 6 |         sign_in_count: u64,
[INFO] [stdout]   |         ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `active`
[INFO] [stdout]  --> src/bin/ch5_structs.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 7 |         active: bool,
[INFO] [stdout]   |         ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `Animal`
[INFO] [stdout]   --> src/bin/ch5_structs.rs:69:12
[INFO] [stdout]    |
[INFO] [stdout] 69 |     struct Animal {};
[INFO] [stdout]    |            ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `nothing_much`
[INFO] [stdout]    --> src/bin/ch5_structs.rs:151:12
[INFO] [stdout]     |
[INFO] [stdout] 151 |         fn nothing_much(&self) {}
[INFO] [stdout]     |            ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `add_to_waitlist`
[INFO] [stdout]   --> src/bin/ch7_modules/main.rs:15:12
[INFO] [stdout]    |
[INFO] [stdout] 15 |         fn add_to_waitlist() {}
[INFO] [stdout]    |            ^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `seat_at_table`
[INFO] [stdout]   --> src/bin/ch7_modules/main.rs:16:12
[INFO] [stdout]    |
[INFO] [stdout] 16 |         fn seat_at_table() {}
[INFO] [stdout]    |            ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `take_order`
[INFO] [stdout]   --> src/bin/ch7_modules/main.rs:20:12
[INFO] [stdout]    |
[INFO] [stdout] 20 |         fn take_order() {}
[INFO] [stdout]    |            ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `serve_order`
[INFO] [stdout]   --> src/bin/ch7_modules/main.rs:21:12
[INFO] [stdout]    |
[INFO] [stdout] 21 |         fn serve_order() {}
[INFO] [stdout]    |            ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `take_payment`
[INFO] [stdout]   --> src/bin/ch7_modules/main.rs:22:12
[INFO] [stdout]    |
[INFO] [stdout] 22 |         fn take_payment() {}
[INFO] [stdout]    |            ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `open`
[INFO] [stdout]   --> src/bin/ch7_modules/main.rs:29:8
[INFO] [stdout]    |
[INFO] [stdout] 29 |     fn open() {}
[INFO] [stdout]    |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `open1`
[INFO] [stdout]   --> src/bin/ch7_modules/main.rs:47:4
[INFO] [stdout]    |
[INFO] [stdout] 47 | fn open1() {}
[INFO] [stdout]    |    ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `open2`
[INFO] [stdout]   --> src/bin/ch7_modules/main.rs:49:8
[INFO] [stdout]    |
[INFO] [stdout] 49 |     fn open2() {}
[INFO] [stdout]    |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `unzip`
[INFO] [stdout]   --> src/bin/ch7_modules/main.rs:52:12
[INFO] [stdout]    |
[INFO] [stdout] 52 |         fn unzip() {
[INFO] [stdout]    |            ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `secret_toast`
[INFO] [stdout]   --> src/bin/ch7_modules/main.rs:63:9
[INFO] [stdout]    |
[INFO] [stdout] 63 |         secret_toast: String, // unaccessible
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum is never used: `Appetizer`
[INFO] [stdout]   --> src/bin/ch7_modules/main.rs:78:14
[INFO] [stdout]    |
[INFO] [stdout] 78 |     pub enum Appetizer {
[INFO] [stdout]    |              ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum is never used: `Dessert`
[INFO] [stdout]   --> src/bin/ch7_modules/main.rs:84:10
[INFO] [stdout]    |
[INFO] [stdout] 84 |     enum Dessert {
[INFO] [stdout]    |          ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `start`
[INFO] [stdout]   --> src/bin/ch7_modules/main.rs:93:16
[INFO] [stdout]    |
[INFO] [stdout] 93 |         pub fn start() {}
[INFO] [stdout]    |                ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `stop`
[INFO] [stdout]   --> src/bin/ch7_modules/main.rs:94:12
[INFO] [stdout]    |
[INFO] [stdout] 94 |         fn stop() {}
[INFO] [stdout]    |            ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `drive`
[INFO] [stdout]    --> src/bin/ch7_modules/main.rs:102:4
[INFO] [stdout]     |
[INFO] [stdout] 102 | fn drive() {
[INFO] [stdout]     |    ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `placeholder`
[INFO] [stdout]    --> src/bin/ch7_modules/main.rs:113:4
[INFO] [stdout]     |
[INFO] [stdout] 113 | fn placeholder() {
[INFO] [stdout]     |    ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `treasure`
[INFO] [stdout]  --> src/bin/ch7_modules/some_file.rs:3:12
[INFO] [stdout]   |
[INFO] [stdout] 3 |     pub fn treasure() {}
[INFO] [stdout]   |            ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `get_treasure`
[INFO] [stdout]    --> src/bin/ch7_modules/main.rs:130:4
[INFO] [stdout]     |
[INFO] [stdout] 130 | fn get_treasure() {
[INFO] [stdout]     |    ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `treasure`
[INFO] [stdout]  --> src/bin/ch7_modules/some_folder/mod.rs:4:12
[INFO] [stdout]   |
[INFO] [stdout] 4 |     pub fn treasure() {}
[INFO] [stdout]   |            ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `get_treasure_again`
[INFO] [stdout]    --> src/bin/ch7_modules/main.rs:138:4
[INFO] [stdout]     |
[INFO] [stdout] 138 | fn get_treasure_again() {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/ch8_common_collections.rs:97:9
[INFO] [stdout]    |
[INFO] [stdout] 97 |     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/ch8_common_collections.rs:98:9
[INFO] [stdout]    |
[INFO] [stdout] 98 |     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/ch8_common_collections.rs:99:9
[INFO] [stdout]    |
[INFO] [stdout] 99 |     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/ch8_common_collections.rs:100:9
[INFO] [stdout]     |
[INFO] [stdout] 100 |     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/ch8_common_collections.rs:101:9
[INFO] [stdout]     |
[INFO] [stdout] 101 |     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/ch8_common_collections.rs:102:9
[INFO] [stdout]     |
[INFO] [stdout] 102 |     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/ch8_common_collections.rs:103:9
[INFO] [stdout]     |
[INFO] [stdout] 103 |     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/ch8_common_collections.rs:104:9
[INFO] [stdout]     |
[INFO] [stdout] 104 |     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/ch8_common_collections.rs:105:9
[INFO] [stdout]     |
[INFO] [stdout] 105 |     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: `s`
[INFO] [stdout]    --> src/bin/ch8_common_collections.rs:123:9
[INFO] [stdout]     |
[INFO] [stdout] 123 |     let s = format!("{}-{}-{}", s1, s2, s3); // tic-tac-toe
[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/ch8_common_collections.rs:10:9
[INFO] [stdout]    |
[INFO] [stdout] 10 |     let mut v: Vec<i32> = Vec::new();
[INFO] [stdout]    |         ----^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 8 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 7 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/bin/ch8_common_collections.rs:87:9
[INFO] [stdout]    |
[INFO] [stdout] 87 |     let mut string = String::new();
[INFO] [stdout]    |         ----^^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]   --> src/bin/ch3_common_concepts.rs:22:9
[INFO] [stdout]    |
[INFO] [stdout] 22 |     let a = [1, 2, 3, 4, 5];
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]   --> src/bin/ch3_common_concepts.rs:23:9
[INFO] [stdout]    |
[INFO] [stdout] 23 |     let a: [i32; 5] = [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/bin/ch3_common_concepts.rs:24:9
[INFO] [stdout]    |
[INFO] [stdout] 24 |     let a = [3; 5]; //  let a = [3, 3, 3, 3, 3];
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/bin/ch3_common_concepts.rs:29:9
[INFO] [stdout]    |
[INFO] [stdout] 29 |     let x = returns_in_functions(5);
[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/bin/ch3_common_concepts.rs:32:9
[INFO] [stdout]    |
[INFO] [stdout] 32 |     let x = 4;
[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/bin/ch3_common_concepts.rs:35:9
[INFO] [stdout]    |
[INFO] [stdout] 35 |     let y = {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `number`
[INFO] [stdout]   --> src/bin/ch3_common_concepts.rs:51:9
[INFO] [stdout]    |
[INFO] [stdout] 51 |     let number = if condition { 5 } else { 6 };
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_number`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `some_number`
[INFO] [stdout]   --> src/bin/ch13_functional_language_features/closures.rs:20:9
[INFO] [stdout]    |
[INFO] [stdout] 20 |     let some_number = double_a_value(23);
[INFO] [stdout]    |         ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_some_number`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 20 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `add_one_v1`
[INFO] [stdout]   --> src/bin/ch13_functional_language_features/closures.rs:24:9
[INFO] [stdout]    |
[INFO] [stdout] 24 |     let add_one_v1 = |x: u32| -> u32 { x + 1 };
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_add_one_v1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `result`
[INFO] [stdout]   --> src/bin/ch13_functional_language_features/closures.rs:30:9
[INFO] [stdout]    |
[INFO] [stdout] 30 |     let result = add_one_v2(23);
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_result`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `list2`
[INFO] [stdout]   --> src/bin/ch13_functional_language_features/iterators.rs:38:9
[INFO] [stdout]    |
[INFO] [stdout] 38 |     let list2: Vec<_> = list.iter().map(|x| x + 1).collect();
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_list2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 28 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `home`
[INFO] [stdout]   --> src/bin/ch6_enums_pattern_matching.rs:33:9
[INFO] [stdout]    |
[INFO] [stdout] 33 |     let home = IpAddr::V4(String::from("127.0.0.1"));
[INFO] [stdout]    |         ^^^^ help: if this is intentional, prefix it with an underscore: `_home`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `loopBack`
[INFO] [stdout]   --> src/bin/ch6_enums_pattern_matching.rs:34:9
[INFO] [stdout]    |
[INFO] [stdout] 34 |     let loopBack = IpAddr::V6(String::from("::1"));
[INFO] [stdout]    |         ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_loopBack`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `some_number`
[INFO] [stdout]   --> src/bin/ch6_enums_pattern_matching.rs:73:9
[INFO] [stdout]    |
[INFO] [stdout] 73 |     let some_number = Some(5);
[INFO] [stdout]    |         ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_some_number`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `some_string`
[INFO] [stdout]   --> src/bin/ch6_enums_pattern_matching.rs:74:9
[INFO] [stdout]    |
[INFO] [stdout] 74 |     let some_string = Some("a string");
[INFO] [stdout]    |         ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_some_string`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `absent_number`
[INFO] [stdout]   --> src/bin/ch6_enums_pattern_matching.rs:76:9
[INFO] [stdout]    |
[INFO] [stdout] 76 |     let absent_number: Option<i32> = None;
[INFO] [stdout]    |         ^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_absent_number`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `absent_string`
[INFO] [stdout]   --> src/bin/ch6_enums_pattern_matching.rs:77:9
[INFO] [stdout]    |
[INFO] [stdout] 77 |     let absent_string: Option<String> = None;
[INFO] [stdout]    |         ^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_absent_string`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]    --> src/bin/ch6_enums_pattern_matching.rs:119:9
[INFO] [stdout]     |
[INFO] [stdout] 119 |     let x = match coin {
[INFO] [stdout]     |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `six`
[INFO] [stdout]    --> src/bin/ch6_enums_pattern_matching.rs:138:9
[INFO] [stdout]     |
[INFO] [stdout] 138 |     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/bin/ch6_enums_pattern_matching.rs:139:9
[INFO] [stdout]     |
[INFO] [stdout] 139 |     let none = plus_one(None);
[INFO] [stdout]     |         ^^^^ help: if this is intentional, prefix it with an underscore: `_none`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `count` is assigned to, but never used
[INFO] [stdout]    --> src/bin/ch6_enums_pattern_matching.rs:166:9
[INFO] [stdout]     |
[INFO] [stdout] 166 |     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/bin/ch6_enums_pattern_matching.rs:170:9
[INFO] [stdout]     |
[INFO] [stdout] 170 |         count += 1;
[INFO] [stdout]     |         ^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `V7`
[INFO] [stdout]   --> src/bin/ch6_enums_pattern_matching.rs:30:9
[INFO] [stdout]    |
[INFO] [stdout] 30 |         V7(u8, u8, u8, u8),
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `Ipv4Addr`
[INFO] [stdout]   --> src/bin/ch6_enums_pattern_matching.rs:37:12
[INFO] [stdout]    |
[INFO] [stdout] 37 |     struct Ipv4Addr {
[INFO] [stdout]    |            ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `Ipv6Addr`
[INFO] [stdout]   --> src/bin/ch6_enums_pattern_matching.rs:41:12
[INFO] [stdout]    |
[INFO] [stdout] 41 |     struct Ipv6Addr {
[INFO] [stdout]    |            ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum is never used: `IpAddrress`
[INFO] [stdout]   --> src/bin/ch6_enums_pattern_matching.rs:45:10
[INFO] [stdout]    |
[INFO] [stdout] 45 |     enum IpAddrress {
[INFO] [stdout]    |          ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Quit`
[INFO] [stdout]   --> src/bin/ch6_enums_pattern_matching.rs:53:9
[INFO] [stdout]    |
[INFO] [stdout] 53 |         Quit,
[INFO] [stdout]    |         ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Move`
[INFO] [stdout]   --> src/bin/ch6_enums_pattern_matching.rs:54:9
[INFO] [stdout]    |
[INFO] [stdout] 54 |         Move { x: i32, y: i32 },
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `ChangeColor`
[INFO] [stdout]   --> src/bin/ch6_enums_pattern_matching.rs:56:9
[INFO] [stdout]    |
[INFO] [stdout] 56 |         ChangeColor(i32, i32, i32),
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `HayPenny`
[INFO] [stdout]   --> src/bin/ch6_enums_pattern_matching.rs:83:9
[INFO] [stdout]    |
[INFO] [stdout] 83 |         HayPenny,
[INFO] [stdout]    |         ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Penny`
[INFO] [stdout]   --> src/bin/ch6_enums_pattern_matching.rs:84:9
[INFO] [stdout]    |
[INFO] [stdout] 84 |         Penny,
[INFO] [stdout]    |         ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Nickel`
[INFO] [stdout]   --> src/bin/ch6_enums_pattern_matching.rs:85:9
[INFO] [stdout]    |
[INFO] [stdout] 85 |         Nickel,
[INFO] [stdout]    |         ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Dime`
[INFO] [stdout]   --> src/bin/ch6_enums_pattern_matching.rs:86:9
[INFO] [stdout]    |
[INFO] [stdout] 86 |         Dime,
[INFO] [stdout]    |         ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Alaska`
[INFO] [stdout]    --> src/bin/ch6_enums_pattern_matching.rs:108:9
[INFO] [stdout]     |
[INFO] [stdout] 108 |         Alaska,
[INFO] [stdout]     |         ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Penny`
[INFO] [stdout]    --> src/bin/ch6_enums_pattern_matching.rs:112:9
[INFO] [stdout]     |
[INFO] [stdout] 112 |         Penny,
[INFO] [stdout]     |         ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Nickel`
[INFO] [stdout]    --> src/bin/ch6_enums_pattern_matching.rs:113:9
[INFO] [stdout]     |
[INFO] [stdout] 113 |         Nickel,
[INFO] [stdout]     |         ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Dime`
[INFO] [stdout]    --> src/bin/ch6_enums_pattern_matching.rs:114:9
[INFO] [stdout]     |
[INFO] [stdout] 114 |         Dime,
[INFO] [stdout]     |         ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Alaska`
[INFO] [stdout]    --> src/bin/ch6_enums_pattern_matching.rs:154:9
[INFO] [stdout]     |
[INFO] [stdout] 154 |         Alaska,
[INFO] [stdout]     |         ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Penny`
[INFO] [stdout]    --> src/bin/ch6_enums_pattern_matching.rs:158:9
[INFO] [stdout]     |
[INFO] [stdout] 158 |         Penny,
[INFO] [stdout]     |         ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Nickel`
[INFO] [stdout]    --> src/bin/ch6_enums_pattern_matching.rs:159:9
[INFO] [stdout]     |
[INFO] [stdout] 159 |         Nickel,
[INFO] [stdout]     |         ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Dime`
[INFO] [stdout]    --> src/bin/ch6_enums_pattern_matching.rs:160:9
[INFO] [stdout]     |
[INFO] [stdout] 160 |         Dime,
[INFO] [stdout]     |         ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `loopBack` should have a snake case name
[INFO] [stdout]   --> src/bin/ch6_enums_pattern_matching.rs:34:9
[INFO] [stdout]    |
[INFO] [stdout] 34 |     let loopBack = IpAddr::V6(String::from("::1"));
[INFO] [stdout]    |         ^^^^^^^^ help: convert the identifier to snake case: `loop_back`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_snake_case)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/bin/ch13_functional_language_features/iterators.rs:78:9
[INFO] [stdout]    |
[INFO] [stdout] 78 |     let mut counter = Counter { count: 0 };
[INFO] [stdout]    |         ----^^^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 31 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 7 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 7 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::clone`
[INFO] [stdout]  --> src/bin/ch10_types_traits_lifetimes.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::clone;
[INFO] [stdout]   |     ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant `ice_cream` should have an upper camel case name
[INFO] [stdout]   --> src/bin/ch7_modules/main.rs:85:9
[INFO] [stdout]    |
[INFO] [stdout] 85 |         ice_cream,
[INFO] [stdout]    |         ^^^^^^^^^ help: convert the identifier to upper camel case: `IceCream`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_camel_case_types)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant `cake` should have an upper camel case name
[INFO] [stdout]   --> src/bin/ch7_modules/main.rs:86:9
[INFO] [stdout]    |
[INFO] [stdout] 86 |         cake,
[INFO] [stdout]    |         ^^^^ help: convert the identifier to upper camel case (notice the capitalization): `Cake`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `array`, `borrow`, `cmp::Ordering`
[INFO] [stdout]    --> src/bin/ch7_modules/main.rs:119:11
[INFO] [stdout]     |
[INFO] [stdout] 119 | use std::{array, borrow, cmp::Ordering};
[INFO] [stdout]     |           ^^^^^  ^^^^^^  ^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `Write`, `self`
[INFO] [stdout]    --> src/bin/ch7_modules/main.rs:122:15
[INFO] [stdout]     |
[INFO] [stdout] 122 | use std::io::{self, Write}; // imports io & Write
[INFO] [stdout]     |               ^^^^  ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::collections::*`
[INFO] [stdout]    --> src/bin/ch7_modules/main.rs:125:5
[INFO] [stdout]     |
[INFO] [stdout] 125 | use std::collections::*;
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::clone`
[INFO] [stdout]  --> src/bin/ch10_types_traits_lifetimes.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::clone;
[INFO] [stdout]   |     ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]  --> src/bin/ch4_ownership.rs:9:9
[INFO] [stdout]   |
[INFO] [stdout] 9 |     let y = x;
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/bin/ch4_ownership.rs:33:9
[INFO] [stdout]    |
[INFO] [stdout] 33 |     let x = calculate_length(&s1);
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `start_slice`
[INFO] [stdout]   --> src/bin/ch4_ownership.rs:63:9
[INFO] [stdout]    |
[INFO] [stdout] 63 |     let start_slice = &s[0..2];
[INFO] [stdout]    |         ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_start_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `end_slice2`
[INFO] [stdout]   --> src/bin/ch4_ownership.rs:66:9
[INFO] [stdout]    |
[INFO] [stdout] 66 |     let end_slice2 = &s[2..s.len()];
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_end_slice2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `text`
[INFO] [stdout]   --> src/bin/ch4_ownership.rs:24:18
[INFO] [stdout]    |
[INFO] [stdout] 24 |     fn eat_value(text: String) {}
[INFO] [stdout]    |                  ^^^^ help: if this is intentional, prefix it with an underscore: `_text`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `text`
[INFO] [stdout]   --> src/bin/ch4_ownership.rs:91:20
[INFO] [stdout]    |
[INFO] [stdout] 91 |     fn takeLiteral(text: &str) {}
[INFO] [stdout]    |                    ^^^^ help: if this is intentional, prefix it with an underscore: `_text`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]    --> src/bin/ch7_modules/main.rs:114:9
[INFO] [stdout]     |
[INFO] [stdout] 114 |     let y: HashMap<i32, i32> = HashMap::new();
[INFO] [stdout]     |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]    --> src/bin/ch7_modules/main.rs:115:9
[INFO] [stdout]     |
[INFO] [stdout] 115 |     let x = HashMap::<i32, i32>::new(); // turbo fish ::<> will be covered in the future
[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/bin/ch7_modules/main.rs:131:9
[INFO] [stdout]     |
[INFO] [stdout] 131 |     let x = some_file::HashMap::<i32, i32>::new();
[INFO] [stdout]     |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `takeLiteral` should have a snake case name
[INFO] [stdout]   --> src/bin/ch4_ownership.rs:91:8
[INFO] [stdout]    |
[INFO] [stdout] 91 |     fn takeLiteral(text: &str) {}
[INFO] [stdout]    |        ^^^^^^^^^^^ help: convert the identifier to snake case: `take_literal`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_snake_case)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `add_to_waitlist`
[INFO] [stdout]   --> src/bin/ch7_modules/main.rs:15:12
[INFO] [stdout]    |
[INFO] [stdout] 15 |         fn add_to_waitlist() {}
[INFO] [stdout]    |            ^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `seat_at_table`
[INFO] [stdout]   --> src/bin/ch7_modules/main.rs:16:12
[INFO] [stdout]    |
[INFO] [stdout] 16 |         fn seat_at_table() {}
[INFO] [stdout]    |            ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `take_order`
[INFO] [stdout]   --> src/bin/ch7_modules/main.rs:20:12
[INFO] [stdout]    |
[INFO] [stdout] 20 |         fn take_order() {}
[INFO] [stdout]    |            ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `serve_order`
[INFO] [stdout]   --> src/bin/ch7_modules/main.rs:21:12
[INFO] [stdout]    |
[INFO] [stdout] 21 |         fn serve_order() {}
[INFO] [stdout]    |            ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `take_payment`
[INFO] [stdout]   --> src/bin/ch7_modules/main.rs:22:12
[INFO] [stdout]    |
[INFO] [stdout] 22 |         fn take_payment() {}
[INFO] [stdout]    |            ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `open`
[INFO] [stdout]   --> src/bin/ch7_modules/main.rs:29:8
[INFO] [stdout]    |
[INFO] [stdout] 29 |     fn open() {}
[INFO] [stdout]    |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `open1`
[INFO] [stdout]   --> src/bin/ch7_modules/main.rs:47:4
[INFO] [stdout]    |
[INFO] [stdout] 47 | fn open1() {}
[INFO] [stdout]    |    ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `open2`
[INFO] [stdout]   --> src/bin/ch7_modules/main.rs:49:8
[INFO] [stdout]    |
[INFO] [stdout] 49 |     fn open2() {}
[INFO] [stdout]    |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `unzip`
[INFO] [stdout]   --> src/bin/ch7_modules/main.rs:52:12
[INFO] [stdout]    |
[INFO] [stdout] 52 |         fn unzip() {
[INFO] [stdout]    |            ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `secret_toast`
[INFO] [stdout]   --> src/bin/ch7_modules/main.rs:63:9
[INFO] [stdout]    |
[INFO] [stdout] 63 |         secret_toast: String, // unaccessible
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum is never used: `Appetizer`
[INFO] [stdout]   --> src/bin/ch7_modules/main.rs:78:14
[INFO] [stdout]    |
[INFO] [stdout] 78 |     pub enum Appetizer {
[INFO] [stdout]    |              ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum is never used: `Dessert`
[INFO] [stdout]   --> src/bin/ch7_modules/main.rs:84:10
[INFO] [stdout]    |
[INFO] [stdout] 84 |     enum Dessert {
[INFO] [stdout]    |          ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `start`
[INFO] [stdout]   --> src/bin/ch7_modules/main.rs:93:16
[INFO] [stdout]    |
[INFO] [stdout] 93 |         pub fn start() {}
[INFO] [stdout]    |                ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `stop`
[INFO] [stdout]   --> src/bin/ch7_modules/main.rs:94:12
[INFO] [stdout]    |
[INFO] [stdout] 94 |         fn stop() {}
[INFO] [stdout]    |            ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `drive`
[INFO] [stdout]    --> src/bin/ch7_modules/main.rs:102:4
[INFO] [stdout]     |
[INFO] [stdout] 102 | fn drive() {
[INFO] [stdout]     |    ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `placeholder`
[INFO] [stdout]    --> src/bin/ch7_modules/main.rs:113:4
[INFO] [stdout]     |
[INFO] [stdout] 113 | fn placeholder() {
[INFO] [stdout]     |    ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `treasure`
[INFO] [stdout]  --> src/bin/ch7_modules/some_file.rs:3:12
[INFO] [stdout]   |
[INFO] [stdout] 3 |     pub fn treasure() {}
[INFO] [stdout]   |            ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `get_treasure`
[INFO] [stdout]    --> src/bin/ch7_modules/main.rs:130:4
[INFO] [stdout]     |
[INFO] [stdout] 130 | fn get_treasure() {
[INFO] [stdout]     |    ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `treasure`
[INFO] [stdout]  --> src/bin/ch7_modules/some_folder/mod.rs:4:12
[INFO] [stdout]   |
[INFO] [stdout] 4 |     pub fn treasure() {}
[INFO] [stdout]   |            ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `get_treasure_again`
[INFO] [stdout]    --> src/bin/ch7_modules/main.rs:138:4
[INFO] [stdout]     |
[INFO] [stdout] 138 | fn get_treasure_again() {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `mixedNums`
[INFO] [stdout]   --> src/bin/ch10_types_traits_lifetimes.rs:31:9
[INFO] [stdout]    |
[INFO] [stdout] 31 |     let mixedNums = MorePoints { x: 5.23, y: 10 }; // x & y can be different values now
[INFO] [stdout]    |         ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_mixedNums`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `t`
[INFO] [stdout]    --> src/bin/ch10_types_traits_lifetimes.rs:112:28
[INFO] [stdout]     |
[INFO] [stdout] 112 |     fn some_function<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/ch10_types_traits_lifetimes.rs:112:34
[INFO] [stdout]     |
[INFO] [stdout] 112 |     fn some_function<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: `item`
[INFO] [stdout]    --> src/bin/ch10_types_traits_lifetimes.rs:121:16
[INFO] [stdout]     |
[INFO] [stdout] 121 |     fn notify3(item: impl Summary + Display) {}
[INFO] [stdout]     |                ^^^^ help: if this is intentional, prefix it with an underscore: `_item`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `some_text`
[INFO] [stdout]    --> src/bin/ch10_types_traits_lifetimes.rs:189:9
[INFO] [stdout]     |
[INFO] [stdout] 189 |     let some_text: &'static str = "I have a static lifetime.";
[INFO] [stdout]     |         ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_some_text`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]    --> src/bin/ch10_types_traits_lifetimes.rs:149:37
[INFO] [stdout]     |
[INFO] [stdout] 149 |     fn simpleReturn<'a>(x: &'a str, y: &str) -> &'a str {
[INFO] [stdout]     |                                     ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]    --> src/bin/ch10_types_traits_lifetimes.rs:167:18
[INFO] [stdout]     |
[INFO] [stdout] 167 |     fn some_word(s: &str) -> &str {
[INFO] [stdout]     |                  ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `mixedNums`
[INFO] [stdout]   --> src/bin/ch10_types_traits_lifetimes.rs:31:9
[INFO] [stdout]    |
[INFO] [stdout] 31 |     let mixedNums = MorePoints { x: 5.23, y: 10 }; // x & y can be different values now
[INFO] [stdout]    |         ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_mixedNums`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `t`
[INFO] [stdout]    --> src/bin/ch10_types_traits_lifetimes.rs:112:28
[INFO] [stdout]     |
[INFO] [stdout] 112 |     fn some_function<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/ch10_types_traits_lifetimes.rs:112:34
[INFO] [stdout]     |
[INFO] [stdout] 112 |     fn some_function<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: `item`
[INFO] [stdout]    --> src/bin/ch10_types_traits_lifetimes.rs:121:16
[INFO] [stdout]     |
[INFO] [stdout] 121 |     fn notify3(item: impl Summary + Display) {}
[INFO] [stdout]     |                ^^^^ help: if this is intentional, prefix it with an underscore: `_item`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 7 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `some_text`
[INFO] [stdout]    --> src/bin/ch10_types_traits_lifetimes.rs:189:9
[INFO] [stdout]     |
[INFO] [stdout] 189 |     let some_text: &'static str = "I have a static lifetime.";
[INFO] [stdout]     |         ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_some_text`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]    --> src/bin/ch10_types_traits_lifetimes.rs:149:37
[INFO] [stdout]     |
[INFO] [stdout] 149 |     fn simpleReturn<'a>(x: &'a str, y: &str) -> &'a str {
[INFO] [stdout]     |                                     ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]    --> src/bin/ch10_types_traits_lifetimes.rs:167:18
[INFO] [stdout]     |
[INFO] [stdout] 167 |     fn some_word(s: &str) -> &str {
[INFO] [stdout]     |                  ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 28 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::thread`
[INFO] [stdout]  --> src/bin/ch13_functional_language_features/closures.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::thread;
[INFO] [stdout]   |     ^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::time::Duration`
[INFO] [stdout]  --> src/bin/ch13_functional_language_features/closures.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use std::time::Duration;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `x`
[INFO] [stdout]   --> src/bin/ch10_types_traits_lifetimes.rs:27:9
[INFO] [stdout]    |
[INFO] [stdout] 27 |         x: T,
[INFO] [stdout]    |         ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `y`
[INFO] [stdout]   --> src/bin/ch10_types_traits_lifetimes.rs:28:9
[INFO] [stdout]    |
[INFO] [stdout] 28 |         y: U,
[INFO] [stdout]    |         ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum is never used: `Option`
[INFO] [stdout]   --> src/bin/ch10_types_traits_lifetimes.rs:34:10
[INFO] [stdout]    |
[INFO] [stdout] 34 |     enum Option<T> {
[INFO] [stdout]    |          ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum is never used: `Result`
[INFO] [stdout]   --> src/bin/ch10_types_traits_lifetimes.rs:39:10
[INFO] [stdout]    |
[INFO] [stdout] 39 |     enum Result<T, E> {
[INFO] [stdout]    |          ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `notify2`
[INFO] [stdout]    --> src/bin/ch10_types_traits_lifetimes.rs:107:8
[INFO] [stdout]     |
[INFO] [stdout] 107 |     fn notify2<T: Summary>(item1: T, item2: T) {
[INFO] [stdout]     |        ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `some_function`
[INFO] [stdout]    --> src/bin/ch10_types_traits_lifetimes.rs:112:8
[INFO] [stdout]     |
[INFO] [stdout] 112 |     fn some_function<T, U>(t: T, u: U) -> i32
[INFO] [stdout]     |        ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `notify3`
[INFO] [stdout]    --> src/bin/ch10_types_traits_lifetimes.rs:121:8
[INFO] [stdout]     |
[INFO] [stdout] 121 |     fn notify3(item: impl Summary + Display) {}
[INFO] [stdout]     |        ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `returns_summarizable`
[INFO] [stdout]    --> src/bin/ch10_types_traits_lifetimes.rs:124:8
[INFO] [stdout]     |
[INFO] [stdout] 124 |     fn returns_summarizable() -> impl Summary {
[INFO] [stdout]     |        ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `simpleReturn`
[INFO] [stdout]    --> src/bin/ch10_types_traits_lifetimes.rs:149:8
[INFO] [stdout]     |
[INFO] [stdout] 149 |     fn simpleReturn<'a>(x: &'a str, y: &str) -> &'a str {
[INFO] [stdout]     |        ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `some_word`
[INFO] [stdout]    --> src/bin/ch10_types_traits_lifetimes.rs:167:8
[INFO] [stdout]     |
[INFO] [stdout] 167 |     fn some_word(s: &str) -> &str {
[INFO] [stdout]     |        ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `some_number`
[INFO] [stdout]    --> src/bin/ch10_types_traits_lifetimes.rs:178:12
[INFO] [stdout]     |
[INFO] [stdout] 178 |         fn some_number(&self) -> i32 {
[INFO] [stdout]     |            ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `alert`
[INFO] [stdout]    --> src/bin/ch10_types_traits_lifetimes.rs:182:12
[INFO] [stdout]     |
[INFO] [stdout] 182 |         fn alert(&self, text: &str) -> &str {
[INFO] [stdout]     |            ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `x`
[INFO] [stdout]   --> src/bin/ch10_types_traits_lifetimes.rs:27:9
[INFO] [stdout]    |
[INFO] [stdout] 27 |         x: T,
[INFO] [stdout]    |         ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `y`
[INFO] [stdout]   --> src/bin/ch10_types_traits_lifetimes.rs:28:9
[INFO] [stdout]    |
[INFO] [stdout] 28 |         y: U,
[INFO] [stdout]    |         ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum is never used: `Option`
[INFO] [stdout]   --> src/bin/ch10_types_traits_lifetimes.rs:34:10
[INFO] [stdout]    |
[INFO] [stdout] 34 |     enum Option<T> {
[INFO] [stdout]    |          ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum is never used: `Result`
[INFO] [stdout]   --> src/bin/ch10_types_traits_lifetimes.rs:39:10
[INFO] [stdout]    |
[INFO] [stdout] 39 |     enum Result<T, E> {
[INFO] [stdout]    |          ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `notify2`
[INFO] [stdout]    --> src/bin/ch10_types_traits_lifetimes.rs:107:8
[INFO] [stdout]     |
[INFO] [stdout] 107 |     fn notify2<T: Summary>(item1: T, item2: T) {
[INFO] [stdout]     |        ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `some_function`
[INFO] [stdout]    --> src/bin/ch10_types_traits_lifetimes.rs:112:8
[INFO] [stdout]     |
[INFO] [stdout] 112 |     fn some_function<T, U>(t: T, u: U) -> i32
[INFO] [stdout]     |        ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `notify3`
[INFO] [stdout]    --> src/bin/ch10_types_traits_lifetimes.rs:121:8
[INFO] [stdout]     |
[INFO] [stdout] 121 |     fn notify3(item: impl Summary + Display) {}
[INFO] [stdout]     |        ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `returns_summarizable`
[INFO] [stdout]    --> src/bin/ch10_types_traits_lifetimes.rs:124:8
[INFO] [stdout]     |
[INFO] [stdout] 124 |     fn returns_summarizable() -> impl Summary {
[INFO] [stdout]     |        ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `simpleReturn`
[INFO] [stdout]    --> src/bin/ch10_types_traits_lifetimes.rs:149:8
[INFO] [stdout]     |
[INFO] [stdout] 149 |     fn simpleReturn<'a>(x: &'a str, y: &str) -> &'a str {
[INFO] [stdout]     |        ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `some_word`
[INFO] [stdout]    --> src/bin/ch10_types_traits_lifetimes.rs:167:8
[INFO] [stdout]     |
[INFO] [stdout] 167 |     fn some_word(s: &str) -> &str {
[INFO] [stdout]     |        ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `some_number`
[INFO] [stdout]    --> src/bin/ch10_types_traits_lifetimes.rs:178:12
[INFO] [stdout]     |
[INFO] [stdout] 178 |         fn some_number(&self) -> i32 {
[INFO] [stdout]     |            ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `alert`
[INFO] [stdout]    --> src/bin/ch10_types_traits_lifetimes.rs:182:12
[INFO] [stdout]     |
[INFO] [stdout] 182 |         fn alert(&self, text: &str) -> &str {
[INFO] [stdout]     |            ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `mixedNums` should have a snake case name
[INFO] [stdout]   --> src/bin/ch10_types_traits_lifetimes.rs:31:9
[INFO] [stdout]    |
[INFO] [stdout] 31 |     let mixedNums = MorePoints { x: 5.23, y: 10 }; // x & y can be different values now
[INFO] [stdout]    |         ^^^^^^^^^ help: convert the identifier to snake case: `mixed_nums`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_snake_case)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `simpleRef` should have a snake case name
[INFO] [stdout]   --> src/bin/ch10_types_traits_lifetimes.rs:46:12
[INFO] [stdout]    |
[INFO] [stdout] 46 |         fn simpleRef(&self) -> &T {
[INFO] [stdout]    |            ^^^^^^^^^ help: convert the identifier to snake case: `simple_ref`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `wholeNums` should have a snake case name
[INFO] [stdout]   --> src/bin/ch10_types_traits_lifetimes.rs:57:12
[INFO] [stdout]    |
[INFO] [stdout] 57 |         fn wholeNums(&self) {
[INFO] [stdout]    |            ^^^^^^^^^ help: convert the identifier to snake case: `whole_nums`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `simpleReturn` should have a snake case name
[INFO] [stdout]    --> src/bin/ch10_types_traits_lifetimes.rs:149:8
[INFO] [stdout]     |
[INFO] [stdout] 149 |     fn simpleReturn<'a>(x: &'a str, y: &str) -> &'a str {
[INFO] [stdout]     |        ^^^^^^^^^^^^ help: convert the identifier to snake case: `simple_return`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `mixedNums` should have a snake case name
[INFO] [stdout]   --> src/bin/ch10_types_traits_lifetimes.rs:31:9
[INFO] [stdout]    |
[INFO] [stdout] 31 |     let mixedNums = MorePoints { x: 5.23, y: 10 }; // x & y can be different values now
[INFO] [stdout]    |         ^^^^^^^^^ help: convert the identifier to snake case: `mixed_nums`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_snake_case)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `simpleRef` should have a snake case name
[INFO] [stdout]   --> src/bin/ch10_types_traits_lifetimes.rs:46:12
[INFO] [stdout]    |
[INFO] [stdout] 46 |         fn simpleRef(&self) -> &T {
[INFO] [stdout]    |            ^^^^^^^^^ help: convert the identifier to snake case: `simple_ref`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `wholeNums` should have a snake case name
[INFO] [stdout]   --> src/bin/ch10_types_traits_lifetimes.rs:57:12
[INFO] [stdout]    |
[INFO] [stdout] 57 |         fn wholeNums(&self) {
[INFO] [stdout]    |            ^^^^^^^^^ help: convert the identifier to snake case: `whole_nums`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `simpleReturn` should have a snake case name
[INFO] [stdout]    --> src/bin/ch10_types_traits_lifetimes.rs:149:8
[INFO] [stdout]     |
[INFO] [stdout] 149 |     fn simpleReturn<'a>(x: &'a str, y: &str) -> &'a str {
[INFO] [stdout]     |        ^^^^^^^^^^^^ help: convert the identifier to snake case: `simple_return`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `home`
[INFO] [stdout]   --> src/bin/ch6_enums_pattern_matching.rs:33:9
[INFO] [stdout]    |
[INFO] [stdout] 33 |     let home = IpAddr::V4(String::from("127.0.0.1"));
[INFO] [stdout]    |         ^^^^ help: if this is intentional, prefix it with an underscore: `_home`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `loopBack`
[INFO] [stdout]   --> src/bin/ch6_enums_pattern_matching.rs:34:9
[INFO] [stdout]    |
[INFO] [stdout] 34 |     let loopBack = IpAddr::V6(String::from("::1"));
[INFO] [stdout]    |         ^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_loopBack`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `some_number`
[INFO] [stdout]   --> src/bin/ch6_enums_pattern_matching.rs:73:9
[INFO] [stdout]    |
[INFO] [stdout] 73 |     let some_number = Some(5);
[INFO] [stdout]    |         ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_some_number`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `some_string`
[INFO] [stdout]   --> src/bin/ch6_enums_pattern_matching.rs:74:9
[INFO] [stdout]    |
[INFO] [stdout] 74 |     let some_string = Some("a string");
[INFO] [stdout]    |         ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_some_string`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `absent_number`
[INFO] [stdout]   --> src/bin/ch6_enums_pattern_matching.rs:76:9
[INFO] [stdout]    |
[INFO] [stdout] 76 |     let absent_number: Option<i32> = None;
[INFO] [stdout]    |         ^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_absent_number`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `absent_string`
[INFO] [stdout]   --> src/bin/ch6_enums_pattern_matching.rs:77:9
[INFO] [stdout]    |
[INFO] [stdout] 77 |     let absent_string: Option<String> = None;
[INFO] [stdout]    |         ^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_absent_string`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]    --> src/bin/ch6_enums_pattern_matching.rs:119:9
[INFO] [stdout]     |
[INFO] [stdout] 119 |     let x = match coin {
[INFO] [stdout]     |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `six`
[INFO] [stdout]    --> src/bin/ch6_enums_pattern_matching.rs:138:9
[INFO] [stdout]     |
[INFO] [stdout] 138 |     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/bin/ch6_enums_pattern_matching.rs:139:9
[INFO] [stdout]     |
[INFO] [stdout] 139 |     let none = plus_one(None);
[INFO] [stdout]     |         ^^^^ help: if this is intentional, prefix it with an underscore: `_none`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `count` is assigned to, but never used
[INFO] [stdout]    --> src/bin/ch6_enums_pattern_matching.rs:166:9
[INFO] [stdout]     |
[INFO] [stdout] 166 |     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/bin/ch6_enums_pattern_matching.rs:170:9
[INFO] [stdout]     |
[INFO] [stdout] 170 |         count += 1;
[INFO] [stdout]     |         ^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout]     = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 24 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 24 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `V7`
[INFO] [stdout]   --> src/bin/ch6_enums_pattern_matching.rs:30:9
[INFO] [stdout]    |
[INFO] [stdout] 30 |         V7(u8, u8, u8, u8),
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `Ipv4Addr`
[INFO] [stdout]   --> src/bin/ch6_enums_pattern_matching.rs:37:12
[INFO] [stdout]    |
[INFO] [stdout] 37 |     struct Ipv4Addr {
[INFO] [stdout]    |            ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `Ipv6Addr`
[INFO] [stdout]   --> src/bin/ch6_enums_pattern_matching.rs:41:12
[INFO] [stdout]    |
[INFO] [stdout] 41 |     struct Ipv6Addr {
[INFO] [stdout]    |            ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum is never used: `IpAddrress`
[INFO] [stdout]   --> src/bin/ch6_enums_pattern_matching.rs:45:10
[INFO] [stdout]    |
[INFO] [stdout] 45 |     enum IpAddrress {
[INFO] [stdout]    |          ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Quit`
[INFO] [stdout]   --> src/bin/ch6_enums_pattern_matching.rs:53:9
[INFO] [stdout]    |
[INFO] [stdout] 53 |         Quit,
[INFO] [stdout]    |         ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Move`
[INFO] [stdout]   --> src/bin/ch6_enums_pattern_matching.rs:54:9
[INFO] [stdout]    |
[INFO] [stdout] 54 |         Move { x: i32, y: i32 },
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `ChangeColor`
[INFO] [stdout]   --> src/bin/ch6_enums_pattern_matching.rs:56:9
[INFO] [stdout]    |
[INFO] [stdout] 56 |         ChangeColor(i32, i32, i32),
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `HayPenny`
[INFO] [stdout]   --> src/bin/ch6_enums_pattern_matching.rs:83:9
[INFO] [stdout]    |
[INFO] [stdout] 83 |         HayPenny,
[INFO] [stdout]    |         ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Penny`
[INFO] [stdout]   --> src/bin/ch6_enums_pattern_matching.rs:84:9
[INFO] [stdout]    |
[INFO] [stdout] 84 |         Penny,
[INFO] [stdout]    |         ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Nickel`
[INFO] [stdout]   --> src/bin/ch6_enums_pattern_matching.rs:85:9
[INFO] [stdout]    |
[INFO] [stdout] 85 |         Nickel,
[INFO] [stdout]    |         ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Dime`
[INFO] [stdout]   --> src/bin/ch6_enums_pattern_matching.rs:86:9
[INFO] [stdout]    |
[INFO] [stdout] 86 |         Dime,
[INFO] [stdout]    |         ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Alaska`
[INFO] [stdout]    --> src/bin/ch6_enums_pattern_matching.rs:108:9
[INFO] [stdout]     |
[INFO] [stdout] 108 |         Alaska,
[INFO] [stdout]     |         ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Penny`
[INFO] [stdout]    --> src/bin/ch6_enums_pattern_matching.rs:112:9
[INFO] [stdout]     |
[INFO] [stdout] 112 |         Penny,
[INFO] [stdout]     |         ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Nickel`
[INFO] [stdout]    --> src/bin/ch6_enums_pattern_matching.rs:113:9
[INFO] [stdout]     |
[INFO] [stdout] 113 |         Nickel,
[INFO] [stdout]     |         ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Dime`
[INFO] [stdout]    --> src/bin/ch6_enums_pattern_matching.rs:114:9
[INFO] [stdout]     |
[INFO] [stdout] 114 |         Dime,
[INFO] [stdout]     |         ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Alaska`
[INFO] [stdout]    --> src/bin/ch6_enums_pattern_matching.rs:154:9
[INFO] [stdout]     |
[INFO] [stdout] 154 |         Alaska,
[INFO] [stdout]     |         ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Penny`
[INFO] [stdout]    --> src/bin/ch6_enums_pattern_matching.rs:158:9
[INFO] [stdout]     |
[INFO] [stdout] 158 |         Penny,
[INFO] [stdout]     |         ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Nickel`
[INFO] [stdout]    --> src/bin/ch6_enums_pattern_matching.rs:159:9
[INFO] [stdout]     |
[INFO] [stdout] 159 |         Nickel,
[INFO] [stdout]     |         ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Dime`
[INFO] [stdout]    --> src/bin/ch6_enums_pattern_matching.rs:160:9
[INFO] [stdout]     |
[INFO] [stdout] 160 |         Dime,
[INFO] [stdout]     |         ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `loopBack` should have a snake case name
[INFO] [stdout]   --> src/bin/ch6_enums_pattern_matching.rs:34:9
[INFO] [stdout]    |
[INFO] [stdout] 34 |     let loopBack = IpAddr::V6(String::from("::1"));
[INFO] [stdout]    |         ^^^^^^^^ help: convert the identifier to snake case: `loop_back`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_snake_case)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v`
[INFO] [stdout]   --> src/bin/ch8_common_collections.rs:10:9
[INFO] [stdout]    |
[INFO] [stdout] 10 |     let mut 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)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v`
[INFO] [stdout]   --> src/bin/ch8_common_collections.rs:25:13
[INFO] [stdout]    |
[INFO] [stdout] 25 |         let v = vec![1, 2, 3, 4];
[INFO] [stdout]    |             ^ help: if this is intentional, prefix it with an underscore: `_v`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `val`
[INFO] [stdout]   --> src/bin/ch8_common_collections.rs:29:9
[INFO] [stdout]    |
[INFO] [stdout] 29 |     let val: &i32 = &v[2];
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_val`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `string`
[INFO] [stdout]   --> src/bin/ch8_common_collections.rs:87:9
[INFO] [stdout]    |
[INFO] [stdout] 87 |     let mut string = String::new();
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_string`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `string2`
[INFO] [stdout]   --> src/bin/ch8_common_collections.rs:88:9
[INFO] [stdout]    |
[INFO] [stdout] 88 |     let string2 = String::from("hello!");
[INFO] [stdout]    |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_string2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `string_example`
[INFO] [stdout]   --> src/bin/ch8_common_collections.rs:92:9
[INFO] [stdout]    |
[INFO] [stdout] 92 |     let string_example = str_example.to_string();
[INFO] [stdout]    |         ^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_string_example`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `hello`
[INFO] [stdout]   --> src/bin/ch8_common_collections.rs:95:9
[INFO] [stdout]    |
[INFO] [stdout] 95 |     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/ch8_common_collections.rs:96:9
[INFO] [stdout]    |
[INFO] [stdout] 96 |     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/ch8_common_collections.rs:97:9
[INFO] [stdout]    |
[INFO] [stdout] 97 |     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/ch8_common_collections.rs:98:9
[INFO] [stdout]    |
[INFO] [stdout] 98 |     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/ch8_common_collections.rs:99:9
[INFO] [stdout]    |
[INFO] [stdout] 99 |     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/ch8_common_collections.rs:100:9
[INFO] [stdout]     |
[INFO] [stdout] 100 |     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/ch8_common_collections.rs:101:9
[INFO] [stdout]     |
[INFO] [stdout] 101 |     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/ch8_common_collections.rs:102:9
[INFO] [stdout]     |
[INFO] [stdout] 102 |     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/ch8_common_collections.rs:103:9
[INFO] [stdout]     |
[INFO] [stdout] 103 |     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/ch8_common_collections.rs:104:9
[INFO] [stdout]     |
[INFO] [stdout] 104 |     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/ch8_common_collections.rs:105:9
[INFO] [stdout]     |
[INFO] [stdout] 105 |     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: `s`
[INFO] [stdout]    --> src/bin/ch8_common_collections.rs:123:9
[INFO] [stdout]     |
[INFO] [stdout] 123 |     let s = format!("{}-{}-{}", s1, s2, s3); // tic-tac-toe
[INFO] [stdout]     |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 31 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/bin/ch8_common_collections.rs:10:9
[INFO] [stdout]    |
[INFO] [stdout] 10 |     let mut v: Vec<i32> = Vec::new();
[INFO] [stdout]    |         ----^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/bin/ch8_common_collections.rs:87:9
[INFO] [stdout]    |
[INFO] [stdout] 87 |     let mut string = String::new();
[INFO] [stdout]    |         ----^^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `some_number`
[INFO] [stdout]   --> src/bin/ch13_functional_language_features/closures.rs:20:9
[INFO] [stdout]    |
[INFO] [stdout] 20 |     let some_number = double_a_value(23);
[INFO] [stdout]    |         ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_some_number`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]  --> src/bin/ch4_ownership.rs:9:9
[INFO] [stdout]   |
[INFO] [stdout] 9 |     let y = x;
[INFO] [stdout]   |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/bin/ch4_ownership.rs:33:9
[INFO] [stdout]    |
[INFO] [stdout] 33 |     let x = calculate_length(&s1);
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `start_slice`
[INFO] [stdout]   --> src/bin/ch4_ownership.rs:63:9
[INFO] [stdout]    |
[INFO] [stdout] 63 |     let start_slice = &s[0..2];
[INFO] [stdout]    |         ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_start_slice`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `end_slice2`
[INFO] [stdout]   --> src/bin/ch4_ownership.rs:66:9
[INFO] [stdout]    |
[INFO] [stdout] 66 |     let end_slice2 = &s[2..s.len()];
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_end_slice2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `text`
[INFO] [stdout]   --> src/bin/ch4_ownership.rs:24:18
[INFO] [stdout]    |
[INFO] [stdout] 24 |     fn eat_value(text: String) {}
[INFO] [stdout]    |                  ^^^^ help: if this is intentional, prefix it with an underscore: `_text`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `text`
[INFO] [stdout]   --> src/bin/ch4_ownership.rs:91:20
[INFO] [stdout]    |
[INFO] [stdout] 91 |     fn takeLiteral(text: &str) {}
[INFO] [stdout]    |                    ^^^^ help: if this is intentional, prefix it with an underscore: `_text`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `add_one_v1`
[INFO] [stdout]   --> src/bin/ch13_functional_language_features/closures.rs:24:9
[INFO] [stdout]    |
[INFO] [stdout] 24 |     let add_one_v1 = |x: u32| -> u32 { x + 1 };
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_add_one_v1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `result`
[INFO] [stdout]   --> src/bin/ch13_functional_language_features/closures.rs:30:9
[INFO] [stdout]    |
[INFO] [stdout] 30 |     let result = add_one_v2(23);
[INFO] [stdout]    |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_result`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `list2`
[INFO] [stdout]   --> src/bin/ch13_functional_language_features/iterators.rs:38:9
[INFO] [stdout]    |
[INFO] [stdout] 38 |     let list2: Vec<_> = list.iter().map(|x| x + 1).collect();
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_list2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/bin/ch13_functional_language_features/iterators.rs:78:9
[INFO] [stdout]    |
[INFO] [stdout] 78 |     let mut counter = Counter { count: 0 };
[INFO] [stdout]    |         ----^^^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `takeLiteral` should have a snake case name
[INFO] [stdout]   --> src/bin/ch4_ownership.rs:91:8
[INFO] [stdout]    |
[INFO] [stdout] 91 |     fn takeLiteral(text: &str) {}
[INFO] [stdout]    |        ^^^^^^^^^^^ help: convert the identifier to snake case: `take_literal`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(non_snake_case)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 7 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 20 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 7 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 8.36s
[INFO] running `Command { std: "docker" "inspect" "4f1d7f08a6b2095e18e3efaa152257673933c1296a8d2828a16f8f40a10fde4b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4f1d7f08a6b2095e18e3efaa152257673933c1296a8d2828a16f8f40a10fde4b", kill_on_drop: false }`
[INFO] [stdout] 4f1d7f08a6b2095e18e3efaa152257673933c1296a8d2828a16f8f40a10fde4b
