[INFO] cloning repository https://github.com/aniruddhha/rust-hands-on
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/aniruddhha/rust-hands-on" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Faniruddhha%2Frust-hands-on", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Faniruddhha%2Frust-hands-on'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 41287cbda4d46438d8a6b2bca656babc0a22bfcd
[INFO] linting aniruddhha/rust-hands-on against nightly for clippy-nonminimal_bool-denied
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Faniruddhha%2Frust-hands-on" "/workspace/builds/worker-7-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7-tc1/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/aniruddhha/rust-hands-on
[INFO] finished tweaking git repo https://github.com/aniruddhha/rust-hands-on
[INFO] tweaked toml for git repo https://github.com/aniruddhha/rust-hands-on written to /workspace/builds/worker-7-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/aniruddhha/rust-hands-on on toolchain nightly
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+nightly" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/aniruddhha/rust-hands-on already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+nightly" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+nightly" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] e53ce8556d6f75f1a496d7598f1ca434dd35bcb5d21a449a0031a35bcbad9446
[INFO] running `Command { std: "docker" "start" "-a" "e53ce8556d6f75f1a496d7598f1ca434dd35bcb5d21a449a0031a35bcbad9446", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "e53ce8556d6f75f1a496d7598f1ca434dd35bcb5d21a449a0031a35bcbad9446", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e53ce8556d6f75f1a496d7598f1ca434dd35bcb5d21a449a0031a35bcbad9446", kill_on_drop: false }`
[INFO] [stdout] e53ce8556d6f75f1a496d7598f1ca434dd35bcb5d21a449a0031a35bcbad9446
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+nightly" "clippy" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 47c2012ec5348e79903adecc8e3dfd40bb8221cf6bebdec12eca534b7f1e45c3
[INFO] running `Command { std: "docker" "start" "-a" "47c2012ec5348e79903adecc8e3dfd40bb8221cf6bebdec12eca534b7f1e45c3", kill_on_drop: false }`
[INFO] [stderr]     Checking rust-hands-on v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: function `basic_4` is never used
[INFO] [stdout]   --> src/bin/07_options_01.rs:28:4
[INFO] [stdout]    |
[INFO] [stdout] 28 | fn basic_4() {
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `basic_5` is never used
[INFO] [stdout]   --> src/bin/07_options_01.rs:38:4
[INFO] [stdout]    |
[INFO] [stdout] 38 | fn basic_5() {
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `basic_6` is never used
[INFO] [stdout]   --> src/bin/07_options_01.rs:45:4
[INFO] [stdout]    |
[INFO] [stdout] 45 | fn basic_6() {
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: used `unwrap()` on `Some` value
[INFO] [stdout]  --> src/bin/07_options_01.rs:4:13
[INFO] [stdout]   |
[INFO] [stdout] 4 |     let v = x.unwrap(); // panic on none
[INFO] [stdout]   |             ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout] help: remove the `Some` and `unwrap()`
[INFO] [stdout]  --> src/bin/07_options_01.rs:3:26
[INFO] [stdout]   |
[INFO] [stdout] 3 |     let x: Option<i32> = Some(10);
[INFO] [stdout]   |                          ^^^^^^^^
[INFO] [stdout]   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_literal_unwrap
[INFO] [stdout]   = note: `#[warn(clippy::unnecessary_literal_unwrap)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: used `unwrap_or()` on `None` value
[INFO] [stdout]   --> src/bin/07_options_01.rs:41:13
[INFO] [stdout]    |
[INFO] [stdout] 41 |     let s = x.unwrap_or("default");
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout] help: remove the `None` and `unwrap_or()`
[INFO] [stdout]   --> src/bin/07_options_01.rs:39:27
[INFO] [stdout]    |
[INFO] [stdout] 39 |     let x: Option<&str> = None;
[INFO] [stdout]    |                           ^^^^
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_literal_unwrap
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: used `unwrap_or()` on `None` value
[INFO] [stdout]   --> src/bin/07_options_01.rs:49:14
[INFO] [stdout]    |
[INFO] [stdout] 49 |     let s1 = x.unwrap_or("default");
[INFO] [stdout]    |              ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout] help: remove the `None` and `unwrap_or()`
[INFO] [stdout]   --> src/bin/07_options_01.rs:47:27
[INFO] [stdout]    |
[INFO] [stdout] 47 |     let x: Option<&str> = None;
[INFO] [stdout]    |                           ^^^^
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_literal_unwrap
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: used `unwrap_or_else()` on `None` value
[INFO] [stdout]   --> src/bin/07_options_01.rs:53:14
[INFO] [stdout]    |
[INFO] [stdout] 53 |     let s2 = x.unwrap_or_else(f);
[INFO] [stdout]    |              ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout] help: remove the `None` and `unwrap_or_else()`
[INFO] [stdout]   --> src/bin/07_options_01.rs:47:27
[INFO] [stdout]    |
[INFO] [stdout] 47 |     let x: Option<&str> = None;
[INFO] [stdout]    |                           ^^^^
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_literal_unwrap
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/bin/02_ownership_borrow_02.rs:14:9
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let mut a = 10; // mutable variable
[INFO] [stdout]    |         ----^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/bin/02_ownership_borrow_02.rs:15:9
[INFO] [stdout]    |
[INFO] [stdout] 15 |     let mut b: &i32 = &a; // immutable reference to a
[INFO] [stdout]    |         ----^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `z` is assigned to, but never used
[INFO] [stdout]   --> src/bin/02_ownership_borrow_02.rs:11:9
[INFO] [stdout]    |
[INFO] [stdout] 11 |     let mut z = y;
[INFO] [stdout]    |         ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: consider using `_z` instead
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `b`
[INFO] [stdout]   --> src/bin/02_ownership_borrow_02.rs:15:9
[INFO] [stdout]    |
[INFO] [stdout] 15 |     let mut b: &i32 = &a; // immutable reference to a
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `z` is never read
[INFO] [stdout]   --> src/bin/02_ownership_borrow_02.rs:12:5
[INFO] [stdout]    |
[INFO] [stdout] 12 |     z = &90;
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout]    = note: `#[warn(unused_assignments)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `add_one` is never used
[INFO] [stdout]  --> src/bin/02_ownership_borrow_02.rs:2:4
[INFO] [stdout]   |
[INFO] [stdout] 2 | fn add_one(x: &mut i32) {
[INFO] [stdout]   |    ^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `flat_mapped`
[INFO] [stdout]   --> src/bin/01_vec.rs:73:9
[INFO] [stdout]    |
[INFO] [stdout] 73 |     let flat_mapped = words.iter().flat_map(|word| word.chars()).collect::<Vec<char>>();
[INFO] [stdout]    |         ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_flat_mapped`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `demo1` is never used
[INFO] [stdout]  --> src/bin/01_vec.rs:1:4
[INFO] [stdout]   |
[INFO] [stdout] 1 | fn demo1() {
[INFO] [stdout]   |    ^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `demo2` is never used
[INFO] [stdout]   --> src/bin/01_vec.rs:30:4
[INFO] [stdout]    |
[INFO] [stdout] 30 | fn demo2() {
[INFO] [stdout]    |    ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: manual implementation of an assign operation
[INFO] [stdout]   --> src/bin/01_vec.rs:39:29
[INFO] [stdout]    |
[INFO] [stdout] 39 |     for x in w.iter_mut() { *x = *x *2 }
[INFO] [stdout]    |                             ^^^^^^^^^^ help: replace it with: `*x *= 2`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#assign_op_pattern
[INFO] [stdout]    = note: `#[warn(clippy::assign_op_pattern)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: you seem to use `.enumerate()` and immediately discard the index
[INFO] [stdout]   --> src/bin/01_vec.rs:60:30
[INFO] [stdout]    |
[INFO] [stdout] 60 |     let uppercased = v.iter().enumerate().map(|(_, el)| el.to_ascii_uppercase() ).collect::<Vec<char>>();
[INFO] [stdout]    |                              ^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unused_enumerate_index
[INFO] [stdout]    = note: `#[warn(clippy::unused_enumerate_index)]` on by default
[INFO] [stdout] help: remove the `.enumerate()` call
[INFO] [stdout]    |
[INFO] [stdout] 60 -     let uppercased = v.iter().enumerate().map(|(_, el)| el.to_ascii_uppercase() ).collect::<Vec<char>>();
[INFO] [stdout] 60 +     let uppercased = v.iter().map(|el| el.to_ascii_uppercase() ).collect::<Vec<char>>();
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `box_demo` is never used
[INFO] [stdout]  --> src/bin/06_smart_pointers_01.rs:4:4
[INFO] [stdout]   |
[INFO] [stdout] 4 | fn box_demo() {
[INFO] [stdout]   |    ^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `rc_demo_1` is never used
[INFO] [stdout]  --> src/bin/06_smart_pointers_01.rs:9:4
[INFO] [stdout]   |
[INFO] [stdout] 9 | fn rc_demo_1() {
[INFO] [stdout]   |    ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `rc_demo_2` is never used
[INFO] [stdout]   --> src/bin/06_smart_pointers_01.rs:25:4
[INFO] [stdout]    |
[INFO] [stdout] 25 | fn rc_demo_2() {
[INFO] [stdout]    |    ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `arc_demo_1` is never used
[INFO] [stdout]   --> src/bin/06_smart_pointers_01.rs:34:4
[INFO] [stdout]    |
[INFO] [stdout] 34 | fn arc_demo_1() {
[INFO] [stdout]    |    ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `refcell_demo_1` is never used
[INFO] [stdout]   --> src/bin/06_smart_pointers_01.rs:51:4
[INFO] [stdout]    |
[INFO] [stdout] 51 | fn refcell_demo_1() {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `refcell_demo_2` is never used
[INFO] [stdout]   --> src/bin/06_smart_pointers_01.rs:62:4
[INFO] [stdout]    |
[INFO] [stdout] 62 | fn refcell_demo_2() {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: useless use of `vec!`
[INFO] [stdout]  --> src/bin/01_vec.rs:2:13
[INFO] [stdout]   |
[INFO] [stdout] 2 |     let v = vec![1, 2, 3, 4];
[INFO] [stdout]   |             ^^^^^^^^^^^^^^^^ help: you can use an array directly: `[1, 2, 3, 4]`
[INFO] [stdout]   |
[INFO] [stdout]   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_vec
[INFO] [stdout]   = note: `#[warn(clippy::useless_vec)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: useless use of `vec!`
[INFO] [stdout]   --> src/bin/01_vec.rs:31:13
[INFO] [stdout]    |
[INFO] [stdout] 31 |     let v = vec![1, 2, 3];
[INFO] [stdout]    |             ^^^^^^^^^^^^^ help: you can use an array directly: `[1, 2, 3]`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_vec
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: useless use of `vec!`
[INFO] [stdout]   --> src/bin/01_vec.rs:55:13
[INFO] [stdout]    |
[INFO] [stdout] 55 |     let v = vec!['a', 'b', 'c'];
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^ help: you can use an array directly: `['a', 'b', 'c']`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_vec
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: useless use of `vec!`
[INFO] [stdout]   --> src/bin/01_vec.rs:65:19
[INFO] [stdout]    |
[INFO] [stdout] 65 |     let numbers = vec![1, 2, 3];
[INFO] [stdout]    |                   ^^^^^^^^^^^^^ help: you can use an array directly: `[1, 2, 3]`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_vec
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: useless use of `vec!`
[INFO] [stdout]   --> src/bin/01_vec.rs:66:19
[INFO] [stdout]    |
[INFO] [stdout] 66 |     let letters = vec!['a', 'b', 'c'];
[INFO] [stdout]    |                   ^^^^^^^^^^^^^^^^^^^ help: you can use an array directly: `['a', 'b', 'c']`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_vec
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: useless use of `vec!`
[INFO] [stdout]   --> src/bin/01_vec.rs:72:17
[INFO] [stdout]    |
[INFO] [stdout] 72 |     let words = vec!["hello", "world"];
[INFO] [stdout]    |                 ^^^^^^^^^^^^^^^^^^^^^^ help: you can use an array directly: `["hello", "world"]`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_vec
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `box_demo` is never used
[INFO] [stdout]  --> src/bin/06_smart_pointers_01.rs:4:4
[INFO] [stdout]   |
[INFO] [stdout] 4 | fn box_demo() {
[INFO] [stdout]   |    ^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `rc_demo_1` is never used
[INFO] [stdout]  --> src/bin/06_smart_pointers_01.rs:9:4
[INFO] [stdout]   |
[INFO] [stdout] 9 | fn rc_demo_1() {
[INFO] [stdout]   |    ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `rc_demo_2` is never used
[INFO] [stdout]   --> src/bin/06_smart_pointers_01.rs:25:4
[INFO] [stdout]    |
[INFO] [stdout] 25 | fn rc_demo_2() {
[INFO] [stdout]    |    ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `arc_demo_1` is never used
[INFO] [stdout]   --> src/bin/06_smart_pointers_01.rs:34:4
[INFO] [stdout]    |
[INFO] [stdout] 34 | fn arc_demo_1() {
[INFO] [stdout]    |    ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `refcell_demo_1` is never used
[INFO] [stdout]   --> src/bin/06_smart_pointers_01.rs:51:4
[INFO] [stdout]    |
[INFO] [stdout] 51 | fn refcell_demo_1() {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `refcell_demo_2` is never used
[INFO] [stdout]   --> src/bin/06_smart_pointers_01.rs:62:4
[INFO] [stdout]    |
[INFO] [stdout] 62 | fn refcell_demo_2() {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/bin/02_ownership_borrow.rs:14:9
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let mut y1 = &mut a;
[INFO] [stdout]    |         ----^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `str1`
[INFO] [stdout]  --> src/bin/02_ownership_borrow.rs:3:9
[INFO] [stdout]   |
[INFO] [stdout] 3 |     let str1: String = "hello".to_owned();
[INFO] [stdout]   |         ^^^^ help: if this is intentional, prefix it with an underscore: `_str1`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `str2`
[INFO] [stdout]  --> src/bin/02_ownership_borrow.rs:5:9
[INFO] [stdout]   |
[INFO] [stdout] 5 |     let str2: &str = "hello again";
[INFO] [stdout]   |         ^^^^ help: if this is intentional, prefix it with an underscore: `_str2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x1`
[INFO] [stdout]  --> src/bin/02_ownership_borrow.rs:9:9
[INFO] [stdout]   |
[INFO] [stdout] 9 |     let x1 = &a;
[INFO] [stdout]   |         ^^ help: if this is intentional, prefix it with an underscore: `_x1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x2`
[INFO] [stdout]   --> src/bin/02_ownership_borrow.rs:11:9
[INFO] [stdout]    |
[INFO] [stdout] 11 |     let x2 = &a;
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_x2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `fmt::write`
[INFO] [stdout]  --> src/bin/08_error_01.rs:2:16
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::{env, fmt::write, fs, io::Error};
[INFO] [stdout]   |                ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `basic_4` is never used
[INFO] [stdout]   --> src/bin/07_options_01.rs:28:4
[INFO] [stdout]    |
[INFO] [stdout] 28 | fn basic_4() {
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `basic_5` is never used
[INFO] [stdout]   --> src/bin/07_options_01.rs:38:4
[INFO] [stdout]    |
[INFO] [stdout] 38 | fn basic_5() {
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `basic_6` is never used
[INFO] [stdout]   --> src/bin/07_options_01.rs:45:4
[INFO] [stdout]    |
[INFO] [stdout] 45 | fn basic_6() {
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: used `unwrap()` on `Some` value
[INFO] [stdout]  --> src/bin/07_options_01.rs:4:13
[INFO] [stdout]   |
[INFO] [stdout] 4 |     let v = x.unwrap(); // panic on none
[INFO] [stdout]   |             ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout] help: remove the `Some` and `unwrap()`
[INFO] [stdout]  --> src/bin/07_options_01.rs:3:26
[INFO] [stdout]   |
[INFO] [stdout] 3 |     let x: Option<i32> = Some(10);
[INFO] [stdout]   |                          ^^^^^^^^
[INFO] [stdout]   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_literal_unwrap
[INFO] [stdout]   = note: `#[warn(clippy::unnecessary_literal_unwrap)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: used `unwrap_or()` on `None` value
[INFO] [stdout]   --> src/bin/07_options_01.rs:41:13
[INFO] [stdout]    |
[INFO] [stdout] 41 |     let s = x.unwrap_or("default");
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout] help: remove the `None` and `unwrap_or()`
[INFO] [stdout]   --> src/bin/07_options_01.rs:39:27
[INFO] [stdout]    |
[INFO] [stdout] 39 |     let x: Option<&str> = None;
[INFO] [stdout]    |                           ^^^^
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_literal_unwrap
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: used `unwrap_or()` on `None` value
[INFO] [stdout]   --> src/bin/07_options_01.rs:49:14
[INFO] [stdout]    |
[INFO] [stdout] 49 |     let s1 = x.unwrap_or("default");
[INFO] [stdout]    |              ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout] help: remove the `None` and `unwrap_or()`
[INFO] [stdout]   --> src/bin/07_options_01.rs:47:27
[INFO] [stdout]    |
[INFO] [stdout] 47 |     let x: Option<&str> = None;
[INFO] [stdout]    |                           ^^^^
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_literal_unwrap
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: used `unwrap_or_else()` on `None` value
[INFO] [stdout]   --> src/bin/07_options_01.rs:53:14
[INFO] [stdout]    |
[INFO] [stdout] 53 |     let s2 = x.unwrap_or_else(f);
[INFO] [stdout]    |              ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout] help: remove the `None` and `unwrap_or_else()`
[INFO] [stdout]   --> src/bin/07_options_01.rs:47:27
[INFO] [stdout]    |
[INFO] [stdout] 47 |     let x: Option<&str> = None;
[INFO] [stdout]    |                           ^^^^
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_literal_unwrap
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `Base` is never used
[INFO] [stdout]  --> src/bin/05_trait_inheritance.rs:1:7
[INFO] [stdout]   |
[INFO] [stdout] 1 | trait Base {
[INFO] [stdout]   |       ^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `Gutter` is never used
[INFO] [stdout]  --> src/bin/05_trait_inheritance.rs:5:7
[INFO] [stdout]   |
[INFO] [stdout] 5 | trait Gutter {
[INFO] [stdout]   |       ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `Margin` is never used
[INFO] [stdout]  --> src/bin/05_trait_inheritance.rs:9:7
[INFO] [stdout]   |
[INFO] [stdout] 9 | trait Margin { 
[INFO] [stdout]   |       ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `Level1` is never used
[INFO] [stdout]   --> src/bin/05_trait_inheritance.rs:13:7
[INFO] [stdout]    |
[INFO] [stdout] 13 | trait Level1: Base + Gutter {
[INFO] [stdout]    |       ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `Level2` is never used
[INFO] [stdout]   --> src/bin/05_trait_inheritance.rs:17:7
[INFO] [stdout]    |
[INFO] [stdout] 17 | trait Level2: Base + Gutter + Margin {
[INFO] [stdout]    |       ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Point` is never constructed
[INFO] [stdout]   --> src/bin/05_trait_inheritance.rs:21:8
[INFO] [stdout]    |
[INFO] [stdout] 21 | struct Point {
[INFO] [stdout]    |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `Base` is never used
[INFO] [stdout]  --> src/bin/05_trait_inheritance.rs:1:7
[INFO] [stdout]   |
[INFO] [stdout] 1 | trait Base {
[INFO] [stdout]   |       ^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `Gutter` is never used
[INFO] [stdout]  --> src/bin/05_trait_inheritance.rs:5:7
[INFO] [stdout]   |
[INFO] [stdout] 5 | trait Gutter {
[INFO] [stdout]   |       ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `Margin` is never used
[INFO] [stdout]  --> src/bin/05_trait_inheritance.rs:9:7
[INFO] [stdout]   |
[INFO] [stdout] 9 | trait Margin { 
[INFO] [stdout]   |       ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/bin/02_ownership_borrow_02.rs:14:9
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let mut a = 10; // mutable variable
[INFO] [stdout]    |         ----^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `Level1` is never used
[INFO] [stdout]   --> src/bin/05_trait_inheritance.rs:13:7
[INFO] [stdout]    |
[INFO] [stdout] 13 | trait Level1: Base + Gutter {
[INFO] [stdout]    |       ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `Level2` is never used
[INFO] [stdout]   --> src/bin/05_trait_inheritance.rs:17:7
[INFO] [stdout]    |
[INFO] [stdout] 17 | trait Level2: Base + Gutter + Margin {
[INFO] [stdout]    |       ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Point` is never constructed
[INFO] [stdout]   --> src/bin/05_trait_inheritance.rs:21:8
[INFO] [stdout]    |
[INFO] [stdout] 21 | struct Point {
[INFO] [stdout]    |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/bin/02_ownership_borrow_02.rs:15:9
[INFO] [stdout]    |
[INFO] [stdout] 15 |     let mut b: &i32 = &a; // immutable reference to a
[INFO] [stdout]    |         ----^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable `z` is assigned to, but never used
[INFO] [stdout]   --> src/bin/02_ownership_borrow_02.rs:11:9
[INFO] [stdout]    |
[INFO] [stdout] 11 |     let mut z = y;
[INFO] [stdout]    |         ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: consider using `_z` instead
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `b`
[INFO] [stdout]   --> src/bin/02_ownership_borrow_02.rs:15:9
[INFO] [stdout]    |
[INFO] [stdout] 15 |     let mut b: &i32 = &a; // immutable reference to a
[INFO] [stdout]    |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `z` is never read
[INFO] [stdout]   --> src/bin/02_ownership_borrow_02.rs:12:5
[INFO] [stdout]    |
[INFO] [stdout] 12 |     z = &90;
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout]    = note: `#[warn(unused_assignments)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `add_one` is never used
[INFO] [stdout]  --> src/bin/02_ownership_borrow_02.rs:2:4
[INFO] [stdout]   |
[INFO] [stdout] 2 | fn add_one(x: &mut i32) {
[INFO] [stdout]   |    ^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: this boolean expression can be simplified
[INFO] [stdout]   --> src/bin/03_03_linked_list.rs:54:16
[INFO] [stdout]    |
[INFO] [stdout] 54 |             if !node.next.is_none() {
[INFO] [stdout]    |                ^^^^^^^^^^^^^^^^^^^^ help: try: `node.next.is_some()`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#nonminimal_bool
[INFO] [stdout]    = note: `#[warn(clippy::nonminimal_bool)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: this `if` statement can be collapsed
[INFO] [stdout]   --> src/bin/03_03_linked_list.rs:65:9
[INFO] [stdout]    |
[INFO] [stdout] 65 | /         if position == 1 {
[INFO] [stdout] 66 | |             if let Some(first) = current.as_mut() {
[INFO] [stdout] 67 | |                 self.head = first.next.take();
[INFO] [stdout] 68 | |                 return;
[INFO] [stdout] 69 | |             }
[INFO] [stdout] 70 | |         }
[INFO] [stdout]    | |_________^
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#collapsible_if
[INFO] [stdout]    = note: `#[warn(clippy::collapsible_if)]` on by default
[INFO] [stdout] help: collapse nested if block
[INFO] [stdout]    |
[INFO] [stdout] 65 ~         if position == 1
[INFO] [stdout] 66 ~             && let Some(first) = current.as_mut() {
[INFO] [stdout] 67 |                 self.head = first.next.take();
[INFO] [stdout] 68 |                 return;
[INFO] [stdout] 69 ~             }
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: this boolean expression can be simplified
[INFO] [stdout]   --> src/bin/03_02_linked_list.rs:12:12
[INFO] [stdout]    |
[INFO] [stdout] 12 |         if !node.next.is_none() { print!(" ,") }
[INFO] [stdout]    |            ^^^^^^^^^^^^^^^^^^^^ help: try: `node.next.is_some()`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#nonminimal_bool
[INFO] [stdout]    = note: `#[warn(clippy::nonminimal_bool)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `basic_1` is never used
[INFO] [stdout]  --> src/bin/08_error_01.rs:4:4
[INFO] [stdout]   |
[INFO] [stdout] 4 | fn basic_1() {
[INFO] [stdout]   |    ^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `basic_2` is never used
[INFO] [stdout]  --> src/bin/08_error_01.rs:9:4
[INFO] [stdout]   |
[INFO] [stdout] 9 | fn basic_2() {
[INFO] [stdout]   |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `basic_3` is never used
[INFO] [stdout]   --> src/bin/08_error_01.rs:18:4
[INFO] [stdout]    |
[INFO] [stdout] 18 | fn basic_3() {
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `basic_4` is never used
[INFO] [stdout]   --> src/bin/08_error_01.rs:27:4
[INFO] [stdout]    |
[INFO] [stdout] 27 | fn basic_4() {
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `basic_6` is never used
[INFO] [stdout]   --> src/bin/08_error_01.rs:50:4
[INFO] [stdout]    |
[INFO] [stdout] 50 | fn basic_6() {
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `basic_7` is never used
[INFO] [stdout]   --> src/bin/08_error_01.rs:86:4
[INFO] [stdout]    |
[INFO] [stdout] 86 | fn basic_7() {
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unneeded `return` statement
[INFO] [stdout]   --> src/bin/08_error_01.rs:23:9
[INFO] [stdout]    |
[INFO] [stdout] 23 |         return;
[INFO] [stdout]    |         ^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stdout]    = note: `#[warn(clippy::needless_return)]` on by default
[INFO] [stdout] help: remove `return`
[INFO] [stdout]    |
[INFO] [stdout] 22 -         eprintln!("Problem in Opening file");
[INFO] [stdout] 23 -         return;
[INFO] [stdout] 22 +         eprintln!("Problem in Opening file");
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/bin/02_ownership_borrow.rs:14:9
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let mut y1 = &mut a;
[INFO] [stdout]    |         ----^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `str1`
[INFO] [stdout]  --> src/bin/02_ownership_borrow.rs:3:9
[INFO] [stdout]   |
[INFO] [stdout] 3 |     let str1: String = "hello".to_owned();
[INFO] [stdout]   |         ^^^^ help: if this is intentional, prefix it with an underscore: `_str1`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `str2`
[INFO] [stdout]  --> src/bin/02_ownership_borrow.rs:5:9
[INFO] [stdout]   |
[INFO] [stdout] 5 |     let str2: &str = "hello again";
[INFO] [stdout]   |         ^^^^ help: if this is intentional, prefix it with an underscore: `_str2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x1`
[INFO] [stdout]  --> src/bin/02_ownership_borrow.rs:9:9
[INFO] [stdout]   |
[INFO] [stdout] 9 |     let x1 = &a;
[INFO] [stdout]   |         ^^ help: if this is intentional, prefix it with an underscore: `_x1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x2`
[INFO] [stdout]   --> src/bin/02_ownership_borrow.rs:11:9
[INFO] [stdout]    |
[INFO] [stdout] 11 |     let x2 = &a;
[INFO] [stdout]    |         ^^ help: if this is intentional, prefix it with an underscore: `_x2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `fmt::write`
[INFO] [stdout]  --> src/bin/08_error_01.rs:2:16
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::{env, fmt::write, fs, io::Error};
[INFO] [stdout]   |                ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: this boolean expression can be simplified
[INFO] [stdout]   --> src/bin/03_02_linked_list.rs:12:12
[INFO] [stdout]    |
[INFO] [stdout] 12 |         if !node.next.is_none() { print!(" ,") }
[INFO] [stdout]    |            ^^^^^^^^^^^^^^^^^^^^ help: try: `node.next.is_some()`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#nonminimal_bool
[INFO] [stdout]    = note: `#[warn(clippy::nonminimal_bool)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: this boolean expression can be simplified
[INFO] [stdout]   --> src/bin/03_03_linked_list.rs:54:16
[INFO] [stdout]    |
[INFO] [stdout] 54 |             if !node.next.is_none() {
[INFO] [stdout]    |                ^^^^^^^^^^^^^^^^^^^^ help: try: `node.next.is_some()`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#nonminimal_bool
[INFO] [stdout]    = note: `#[warn(clippy::nonminimal_bool)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: this `if` statement can be collapsed
[INFO] [stdout]   --> src/bin/03_03_linked_list.rs:65:9
[INFO] [stdout]    |
[INFO] [stdout] 65 | /         if position == 1 {
[INFO] [stdout] 66 | |             if let Some(first) = current.as_mut() {
[INFO] [stdout] 67 | |                 self.head = first.next.take();
[INFO] [stdout] 68 | |                 return;
[INFO] [stdout] 69 | |             }
[INFO] [stdout] 70 | |         }
[INFO] [stdout]    | |_________^
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#collapsible_if
[INFO] [stdout]    = note: `#[warn(clippy::collapsible_if)]` on by default
[INFO] [stdout] help: collapse nested if block
[INFO] [stdout]    |
[INFO] [stdout] 65 ~         if position == 1
[INFO] [stdout] 66 ~             && let Some(first) = current.as_mut() {
[INFO] [stdout] 67 |                 self.head = first.next.take();
[INFO] [stdout] 68 |                 return;
[INFO] [stdout] 69 ~             }
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `flat_mapped`
[INFO] [stdout]   --> src/bin/01_vec.rs:73:9
[INFO] [stdout]    |
[INFO] [stdout] 73 |     let flat_mapped = words.iter().flat_map(|word| word.chars()).collect::<Vec<char>>();
[INFO] [stdout]    |         ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_flat_mapped`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `demo1` is never used
[INFO] [stdout]  --> src/bin/01_vec.rs:1:4
[INFO] [stdout]   |
[INFO] [stdout] 1 | fn demo1() {
[INFO] [stdout]   |    ^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `demo2` is never used
[INFO] [stdout]   --> src/bin/01_vec.rs:30:4
[INFO] [stdout]    |
[INFO] [stdout] 30 | fn demo2() {
[INFO] [stdout]    |    ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: manual implementation of an assign operation
[INFO] [stdout]   --> src/bin/01_vec.rs:39:29
[INFO] [stdout]    |
[INFO] [stdout] 39 |     for x in w.iter_mut() { *x = *x *2 }
[INFO] [stdout]    |                             ^^^^^^^^^^ help: replace it with: `*x *= 2`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#assign_op_pattern
[INFO] [stdout]    = note: `#[warn(clippy::assign_op_pattern)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: you seem to use `.enumerate()` and immediately discard the index
[INFO] [stdout]   --> src/bin/01_vec.rs:60:30
[INFO] [stdout]    |
[INFO] [stdout] 60 |     let uppercased = v.iter().enumerate().map(|(_, el)| el.to_ascii_uppercase() ).collect::<Vec<char>>();
[INFO] [stdout]    |                              ^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unused_enumerate_index
[INFO] [stdout]    = note: `#[warn(clippy::unused_enumerate_index)]` on by default
[INFO] [stdout] help: remove the `.enumerate()` call
[INFO] [stdout]    |
[INFO] [stdout] 60 -     let uppercased = v.iter().enumerate().map(|(_, el)| el.to_ascii_uppercase() ).collect::<Vec<char>>();
[INFO] [stdout] 60 +     let uppercased = v.iter().map(|el| el.to_ascii_uppercase() ).collect::<Vec<char>>();
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: useless use of `vec!`
[INFO] [stdout]  --> src/bin/01_vec.rs:2:13
[INFO] [stdout]   |
[INFO] [stdout] 2 |     let v = vec![1, 2, 3, 4];
[INFO] [stdout]   |             ^^^^^^^^^^^^^^^^ help: you can use an array directly: `[1, 2, 3, 4]`
[INFO] [stdout]   |
[INFO] [stdout]   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_vec
[INFO] [stdout]   = note: `#[warn(clippy::useless_vec)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: useless use of `vec!`
[INFO] [stdout]   --> src/bin/01_vec.rs:31:13
[INFO] [stdout]    |
[INFO] [stdout] 31 |     let v = vec![1, 2, 3];
[INFO] [stdout]    |             ^^^^^^^^^^^^^ help: you can use an array directly: `[1, 2, 3]`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_vec
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: useless use of `vec!`
[INFO] [stdout]   --> src/bin/01_vec.rs:55:13
[INFO] [stdout]    |
[INFO] [stdout] 55 |     let v = vec!['a', 'b', 'c'];
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^ help: you can use an array directly: `['a', 'b', 'c']`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_vec
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: useless use of `vec!`
[INFO] [stdout]   --> src/bin/01_vec.rs:65:19
[INFO] [stdout]    |
[INFO] [stdout] 65 |     let numbers = vec![1, 2, 3];
[INFO] [stdout]    |                   ^^^^^^^^^^^^^ help: you can use an array directly: `[1, 2, 3]`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_vec
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: useless use of `vec!`
[INFO] [stdout]   --> src/bin/01_vec.rs:66:19
[INFO] [stdout]    |
[INFO] [stdout] 66 |     let letters = vec!['a', 'b', 'c'];
[INFO] [stdout]    |                   ^^^^^^^^^^^^^^^^^^^ help: you can use an array directly: `['a', 'b', 'c']`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_vec
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: useless use of `vec!`
[INFO] [stdout]   --> src/bin/01_vec.rs:72:17
[INFO] [stdout]    |
[INFO] [stdout] 72 |     let words = vec!["hello", "world"];
[INFO] [stdout]    |                 ^^^^^^^^^^^^^^^^^^^^^^ help: you can use an array directly: `["hello", "world"]`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_vec
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `basic_1` is never used
[INFO] [stdout]  --> src/bin/08_error_01.rs:4:4
[INFO] [stdout]   |
[INFO] [stdout] 4 | fn basic_1() {
[INFO] [stdout]   |    ^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `basic_2` is never used
[INFO] [stdout]  --> src/bin/08_error_01.rs:9:4
[INFO] [stdout]   |
[INFO] [stdout] 9 | fn basic_2() {
[INFO] [stdout]   |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `basic_3` is never used
[INFO] [stdout]   --> src/bin/08_error_01.rs:18:4
[INFO] [stdout]    |
[INFO] [stdout] 18 | fn basic_3() {
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `basic_4` is never used
[INFO] [stdout]   --> src/bin/08_error_01.rs:27:4
[INFO] [stdout]    |
[INFO] [stdout] 27 | fn basic_4() {
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `basic_6` is never used
[INFO] [stdout]   --> src/bin/08_error_01.rs:50:4
[INFO] [stdout]    |
[INFO] [stdout] 50 | fn basic_6() {
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `basic_7` is never used
[INFO] [stdout]   --> src/bin/08_error_01.rs:86:4
[INFO] [stdout]    |
[INFO] [stdout] 86 | fn basic_7() {
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unneeded `return` statement
[INFO] [stdout]   --> src/bin/08_error_01.rs:23:9
[INFO] [stdout]    |
[INFO] [stdout] 23 |         return;
[INFO] [stdout]    |         ^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stdout]    = note: `#[warn(clippy::needless_return)]` on by default
[INFO] [stdout] help: remove `return`
[INFO] [stdout]    |
[INFO] [stdout] 22 -         eprintln!("Problem in Opening file");
[INFO] [stdout] 23 -         return;
[INFO] [stdout] 22 +         eprintln!("Problem in Opening file");
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.77s
[INFO] running `Command { std: "docker" "inspect" "47c2012ec5348e79903adecc8e3dfd40bb8221cf6bebdec12eca534b7f1e45c3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "47c2012ec5348e79903adecc8e3dfd40bb8221cf6bebdec12eca534b7f1e45c3", kill_on_drop: false }`
[INFO] [stdout] 47c2012ec5348e79903adecc8e3dfd40bb8221cf6bebdec12eca534b7f1e45c3