[INFO] cloning repository https://github.com/elycruz/rust-book
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/elycruz/rust-book" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Felycruz%2Frust-book", kill_on_drop: false }`
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[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 437000fc30c4b3e08e8c37934a38856fc5960efd
[INFO] linting elycruz/rust-book against nightly for clippy-nonminimal_bool-denied
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Felycruz%2Frust-book" "/workspace/builds/worker-6-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc1/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/elycruz/rust-book
[INFO] finished tweaking git repo https://github.com/elycruz/rust-book
[INFO] tweaked toml for git repo https://github.com/elycruz/rust-book written to /workspace/builds/worker-6-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/elycruz/rust-book 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/elycruz/rust-book 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 }`
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[INFO] [stderr]   Downloaded memchr v2.2.1
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[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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] 50313f8690595c62560949ea6d94fb45c1827046274bb4fc71f74cb7631ddb0f
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[INFO] [stderr]    Compiling libc v0.2.62
[INFO] [stderr]    Compiling getrandom v0.1.11
[INFO] [stderr]     Checking cfg-if v0.1.9
[INFO] [stderr]    Compiling memchr v2.2.1
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[INFO] [stderr]     Checking c2-chacha v0.2.2
[INFO] [stderr]     Checking atty v0.2.13
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[INFO] [stderr]     Checking rand_core v0.5.1
[INFO] [stderr]     Checking rand_chacha v0.2.1
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[INFO] [stderr]     Checking regex v1.2.1
[INFO] [stderr]     Checking rust-book v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: function `mean` is never used
[INFO] [stdout]  --> chp8/mean_and_mode.rs:3:4
[INFO] [stdout]   |
[INFO] [stdout] 3 | fn mean(v: &Vec<f64>) -> f64 {
[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 `mode` is never used
[INFO] [stdout]   --> chp8/mean_and_mode.rs:11:4
[INFO] [stdout]    |
[INFO] [stdout] 11 | fn mode(vs: &Vec<f64>) -> f64 {
[INFO] [stdout]    |    ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unneeded `return` statement
[INFO] [stdout]  --> chp8/mean_and_mode.rs:8:5
[INFO] [stdout]   |
[INFO] [stdout] 8 |     return sum / (v.len() as f64);
[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] 8 -     return sum / (v.len() as f64);
[INFO] [stdout] 8 +     sum / (v.len() as f64)
[INFO] [stdout]   |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: deref which would be done by auto-deref
[INFO] [stdout]   --> chp3/twelve_days_of_christmas.rs:58:45
[INFO] [stdout]    |
[INFO] [stdout] 58 |                 println!("{:}", ucase_first(*line));
[INFO] [stdout]    |                                             ^^^^^ help: try: `line`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#explicit_auto_deref
[INFO] [stdout]    = note: `#[warn(clippy::explicit_auto_deref)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: panic message is not a string literal
[INFO] [stdout]   --> chp8/mean_and_mode.rs:45:26
[INFO] [stdout]    |
[INFO] [stdout] 45 |         Err(e) => panic!(e)
[INFO] [stdout]    |                          ^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this usage of `panic!()` is deprecated; it will be a hard error in Rust 2021
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/panic-macro-consistency.html>
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/panic-macro-consistency.html>
[INFO] [stdout]    = note: `#[warn(non_fmt_panics)]` (part of `#[warn(rust_2021_compatibility)]`) on by default
[INFO] [stdout] help: add a "{}" format string to `Display` the message
[INFO] [stdout]    |
[INFO] [stdout] 45 |         Err(e) => panic!("{}", e)
[INFO] [stdout]    |                          +++++
[INFO] [stdout] help: or use std::panic::panic_any instead
[INFO] [stdout]    |
[INFO] [stdout] 45 -         Err(e) => panic!(e)
[INFO] [stdout] 45 +         Err(e) => std::panic::panic_any(e)
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: empty line after doc comment
[INFO] [stdout]  --> chp3/fib_lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | / /**
[INFO] [stdout] 2 | |  * @reference https://www.goldennumber.net/math/
[INFO] [stdout] 3 | |  */
[INFO] [stdout] 4 | |
[INFO] [stdout]   | |_^
[INFO] [stdout] 5 |   static FIVE_O: f64 = 5.0;
[INFO] [stdout]   |   ------------- the comment documents this static item
[INFO] [stdout]   |
[INFO] [stdout]   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#empty_line_after_doc_comments
[INFO] [stdout]   = note: `#[warn(clippy::empty_line_after_doc_comments)]` on by default
[INFO] [stdout]   = help: if the empty line is unintentional, remove it
[INFO] [stdout] help: if the comment should document the parent module use an inner doc comment
[INFO] [stdout]   |
[INFO] [stdout] 1 - /**
[INFO] [stdout] 1 + /*!
[INFO] [stdout]   |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: empty line after doc comment
[INFO] [stdout]  --> chp3/fib_lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | / /**
[INFO] [stdout] 2 | |  * @reference https://www.goldennumber.net/math/
[INFO] [stdout] 3 | |  */
[INFO] [stdout] 4 | |
[INFO] [stdout]   | |_^
[INFO] [stdout] 5 |   static FIVE_O: f64 = 5.0;
[INFO] [stdout]   |   ------------- the comment documents this static item
[INFO] [stdout]   |
[INFO] [stdout]   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#empty_line_after_doc_comments
[INFO] [stdout]   = note: `#[warn(clippy::empty_line_after_doc_comments)]` on by default
[INFO] [stdout]   = help: if the empty line is unintentional, remove it
[INFO] [stdout] help: if the comment should document the parent module use an inner doc comment
[INFO] [stdout]   |
[INFO] [stdout] 1 - /**
[INFO] [stdout] 1 + /*!
[INFO] [stdout]   |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: empty line after doc comment
[INFO] [stdout]  --> chp8/piglatin.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | / /**
[INFO] [stdout] 2 | |  * Convert strings to pig latin.
[INFO] [stdout] 3 | |  * The first consonant of each word is moved to the end of the word and “ay” is added, so “first” becomes “irst-fay”.
[INFO] [stdout] 4 | |  * Words that start with a vowel have “hay” added to the end instead (“apple” becomes “apple-hay”).
[INFO] [stdout] 5 | |  * Keep in mind the details about UTF-8 encoding!
[INFO] [stdout] 6 | |  */
[INFO] [stdout] 7 | |
[INFO] [stdout]   | |_^
[INFO] [stdout] 8 |   use std::env;
[INFO] [stdout]   |   - the comment documents this `use` import
[INFO] [stdout]   |
[INFO] [stdout]   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#empty_line_after_doc_comments
[INFO] [stdout]   = note: `#[warn(clippy::empty_line_after_doc_comments)]` on by default
[INFO] [stdout]   = help: if the empty line is unintentional, remove it
[INFO] [stdout] help: if the comment should document the crate use an inner doc comment
[INFO] [stdout]   |
[INFO] [stdout] 1 - /**
[INFO] [stdout] 1 + /*!
[INFO] [stdout]   |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: static `FIVE_O` is never used
[INFO] [stdout]  --> chp3/fib_lib.rs:5:8
[INFO] [stdout]   |
[INFO] [stdout] 5 | static FIVE_O: f64 = 5.0;
[INFO] [stdout]   |        ^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: static `O_FIVE` is never used
[INFO] [stdout]  --> chp3/fib_lib.rs:7:8
[INFO] [stdout]   |
[INFO] [stdout] 7 | static O_FIVE: f64 = 0.5;
[INFO] [stdout]   |        ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `get_phi` is never used
[INFO] [stdout]   --> chp3/fib_lib.rs:12:4
[INFO] [stdout]    |
[INFO] [stdout] 12 | fn get_phi() -> f64 {
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `nth_fib` is never used
[INFO] [stdout]   --> chp3/fib_lib.rs:31:8
[INFO] [stdout]    |
[INFO] [stdout] 31 | pub fn nth_fib(nth: i32) -> i64 {
[INFO] [stdout]    |        ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: manual implementation of an assign operation
[INFO] [stdout]   --> chp3/fib_lib.rs:25:9
[INFO] [stdout]    |
[INFO] [stdout] 25 |         a = a + b;
[INFO] [stdout]    |         ^^^^^^^^^ help: replace it with: `a += b`
[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: manual implementation of an assign operation
[INFO] [stdout]   --> chp3/fib_lib.rs:26:9
[INFO] [stdout]    |
[INFO] [stdout] 26 |         b = a + b;
[INFO] [stdout]    |         ^^^^^^^^^ help: replace it with: `b += a`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#assign_op_pattern
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unneeded `return` statement
[INFO] [stdout]   --> chp3/fib_lib.rs:37:5
[INFO] [stdout]    |
[INFO] [stdout] 37 |     return 0;
[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] 37 -     return 0;
[INFO] [stdout] 37 +     0
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: this import is redundant
[INFO] [stdout]  --> chp2/guessing_game.rs:4:1
[INFO] [stdout]   |
[INFO] [stdout] 4 | use rand;
[INFO] [stdout]   | ^^^^^^^^^ help: remove it entirely
[INFO] [stdout]   |
[INFO] [stdout]   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#single_component_path_imports
[INFO] [stdout]   = note: `#[warn(clippy::single_component_path_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unneeded `return` statement
[INFO] [stdout]   --> chp8/main.rs:42:5
[INFO] [stdout]    |
[INFO] [stdout] 42 |     return out;
[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] 42 -     return out;
[INFO] [stdout] 42 +     out
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unneeded `return` statement
[INFO] [stdout]   --> chp8/main.rs:55:5
[INFO] [stdout]    |
[INFO] [stdout] 55 |     return Some(last);
[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] help: remove `return`
[INFO] [stdout]    |
[INFO] [stdout] 55 -     return Some(last);
[INFO] [stdout] 55 +     Some(last)
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: writing `&Vec` instead of `&[_]` involves a new object where a slice will do
[INFO] [stdout]   --> chp8/main.rs:45:32
[INFO] [stdout]    |
[INFO] [stdout] 45 | fn maximum<T: Ord + Debug>(xs: &Vec<T>) -> Option<&T> {
[INFO] [stdout]    |                                ^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#ptr_arg
[INFO] [stdout]    = note: `#[warn(clippy::ptr_arg)]` on by default
[INFO] [stdout] help: change this to
[INFO] [stdout]    |
[INFO] [stdout] 45 - fn maximum<T: Ord + Debug>(xs: &Vec<T>) -> Option<&T> {
[INFO] [stdout] 45 + fn maximum<T: Ord + Debug>(xs: &[T]) -> Option<&T> {
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: length comparison to zero
[INFO] [stdout]   --> chp8/main.rs:46:8
[INFO] [stdout]    |
[INFO] [stdout] 46 |     if xs.len() == 0 {
[INFO] [stdout]    |        ^^^^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `xs.is_empty()`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#len_zero
[INFO] [stdout]    = note: `#[warn(clippy::len_zero)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: deref which would be done by auto-deref
[INFO] [stdout]   --> chp3/twelve_days_of_christmas.rs:58:45
[INFO] [stdout]    |
[INFO] [stdout] 58 |                 println!("{:}", ucase_first(*line));
[INFO] [stdout]    |                                             ^^^^^ help: try: `line`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#explicit_auto_deref
[INFO] [stdout]    = note: `#[warn(clippy::explicit_auto_deref)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: name `ADD` contains a capitalized acronym
[INFO] [stdout]   --> chp8/company_directory.rs:13:5
[INFO] [stdout]    |
[INFO] [stdout] 13 |     ADD,
[INFO] [stdout]    |     ^^^ help: consider making the acronym lowercase, except the initial letter: `Add`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#upper_case_acronyms
[INFO] [stdout]    = note: `#[warn(clippy::upper_case_acronyms)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: name `LIST` contains a capitalized acronym
[INFO] [stdout]   --> chp8/company_directory.rs:14:5
[INFO] [stdout]    |
[INFO] [stdout] 14 |     LIST,
[INFO] [stdout]    |     ^^^^ help: consider making the acronym lowercase, except the initial letter: `List`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#upper_case_acronyms
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: name `HELP` contains a capitalized acronym
[INFO] [stdout]   --> chp8/company_directory.rs:15:5
[INFO] [stdout]    |
[INFO] [stdout] 15 |     HELP,
[INFO] [stdout]    |     ^^^^ help: consider making the acronym lowercase, except the initial letter: `Help`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#upper_case_acronyms
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: name `COMMANDS` contains a capitalized acronym
[INFO] [stdout]   --> chp8/company_directory.rs:16:5
[INFO] [stdout]    |
[INFO] [stdout] 16 |     COMMANDS,
[INFO] [stdout]    |     ^^^^^^^^ help: consider making the acronym lowercase, except the initial letter: `Commands`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#upper_case_acronyms
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: name `EXIT` contains a capitalized acronym
[INFO] [stdout]   --> chp8/company_directory.rs:17:5
[INFO] [stdout]    |
[INFO] [stdout] 17 |     EXIT,
[INFO] [stdout]    |     ^^^^ help: consider making the acronym lowercase, except the initial letter: `Exit`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#upper_case_acronyms
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: name `UNKNOWN` contains a capitalized acronym
[INFO] [stdout]   --> chp8/company_directory.rs:18:5
[INFO] [stdout]    |
[INFO] [stdout] 18 |     UNKNOWN
[INFO] [stdout]    |     ^^^^^^^ help: consider making the acronym lowercase, except the initial letter: `Unknown`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#upper_case_acronyms
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: manual implementation of an assign operation
[INFO] [stdout]   --> chp3/fib_lib.rs:25:9
[INFO] [stdout]    |
[INFO] [stdout] 25 |         a = a + b;
[INFO] [stdout]    |         ^^^^^^^^^ help: replace it with: `a += b`
[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: manual implementation of an assign operation
[INFO] [stdout]   --> chp3/fib_lib.rs:26:9
[INFO] [stdout]    |
[INFO] [stdout] 26 |         b = a + b;
[INFO] [stdout]    |         ^^^^^^^^^ help: replace it with: `b += a`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#assign_op_pattern
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unneeded `return` statement
[INFO] [stdout]   --> chp3/fib_lib.rs:37:5
[INFO] [stdout]    |
[INFO] [stdout] 37 |     return 0;
[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] 37 -     return 0;
[INFO] [stdout] 37 +     0
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the variable `i` is used as a loop counter
[INFO] [stdout]   --> chp3/fib_lib.rs:50:9
[INFO] [stdout]    |
[INFO] [stdout] 50 |         for n in test_cases.iter() {
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `for (i, n) in test_cases.iter().enumerate()`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#explicit_counter_loop
[INFO] [stdout]    = note: `#[warn(clippy::explicit_counter_loop)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the variable `i` is used as a loop counter
[INFO] [stdout]   --> chp3/fib_lib.rs:72:13
[INFO] [stdout]    |
[INFO] [stdout] 72 |             for n2 in result.iter() {
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `for (i, n2) in result.iter().enumerate()`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#explicit_counter_loop
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unneeded `return` statement
[INFO] [stdout]   --> chp8/piglatin.rs:57:5
[INFO] [stdout]    |
[INFO] [stdout] 57 |     return s.to_string();
[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] 57 -     return s.to_string();
[INFO] [stdout] 57 +     s.to_string()
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: length comparison to zero
[INFO] [stdout]   --> chp8/piglatin.rs:34:8
[INFO] [stdout]    |
[INFO] [stdout] 34 |     if s.len() == 0 {
[INFO] [stdout]    |        ^^^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `s.is_empty()`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#len_zero
[INFO] [stdout]    = note: `#[warn(clippy::len_zero)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unneeded `return` statement
[INFO] [stdout]   --> chp8/piglatin.rs:72:5
[INFO] [stdout]    |
[INFO] [stdout] 72 |     return out;
[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] help: remove `return`
[INFO] [stdout]    |
[INFO] [stdout] 72 -     return out;
[INFO] [stdout] 72 +     out
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the variable `i` is used as a loop counter
[INFO] [stdout]   --> chp8/piglatin.rs:65:5
[INFO] [stdout]    |
[INFO] [stdout] 65 |     for word in words  {
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^ help: consider using: `for (i, word) in words.into_iter().enumerate()`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#explicit_counter_loop
[INFO] [stdout]    = note: `#[warn(clippy::explicit_counter_loop)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unneeded `return` statement
[INFO] [stdout]   --> chp8/piglatin.rs:87:5
[INFO] [stdout]    |
[INFO] [stdout] 87 |     return out;
[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] help: remove `return`
[INFO] [stdout]    |
[INFO] [stdout] 87 -     return out;
[INFO] [stdout] 87 +     out
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the variable `i` is used as a loop counter
[INFO] [stdout]   --> chp8/piglatin.rs:80:5
[INFO] [stdout]    |
[INFO] [stdout] 80 |     for line in lines {
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^ help: consider using: `for (i, line) in lines.into_iter().enumerate()`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#explicit_counter_loop
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: useless use of `vec!`
[INFO] [stdout]    --> chp8/piglatin.rs:115:36
[INFO] [stdout]     |
[INFO] [stdout] 115 |           for (control, expected) in vec![
[INFO] [stdout]     |  ____________________________________^
[INFO] [stdout] 116 | |             ("hello", "ellohay"),
[INFO] [stdout] 117 | |             ("abc", "abchay"),
[INFO] [stdout] 118 | |             ("road", "oadray"),
[INFO] [stdout] 119 | |             ("first", "irstfay")
[INFO] [stdout] 120 | |         ] {
[INFO] [stdout]     | |_________^
[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] help: you can use an array directly
[INFO] [stdout]     |
[INFO] [stdout] 115 ~         for (control, expected) in [("hello", "ellohay"),
[INFO] [stdout] 116 +             ("abc", "abchay"),
[INFO] [stdout] 117 +             ("road", "oadray"),
[INFO] [stdout] 118 ~             ("first", "irstfay")] {
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: useless use of `vec!`
[INFO] [stdout]    --> chp8/piglatin.rs:129:36
[INFO] [stdout]     |
[INFO] [stdout] 129 |           for (control, expected) in vec![
[INFO] [stdout]     |  ____________________________________^
[INFO] [stdout] 130 | |             ("hello", "ellohay"),
[INFO] [stdout] 131 | |             ("hello world", "ellohay orldway"),
[INFO] [stdout] 132 | |             ("abc today", "abchay odaytay"),
[INFO] [stdout] 133 | |             ("all your base are belong to us", "allhay ouryay asebay arehay elongbay otay ushay"),
[INFO] [stdout] 134 | |         ] {
[INFO] [stdout]     | |_________^
[INFO] [stdout]     |
[INFO] [stdout]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_vec
[INFO] [stdout] help: you can use an array directly
[INFO] [stdout]     |
[INFO] [stdout] 129 ~         for (control, expected) in [("hello", "ellohay"),
[INFO] [stdout] 130 +             ("hello world", "ellohay orldway"),
[INFO] [stdout] 131 +             ("abc today", "abchay odaytay"),
[INFO] [stdout] 132 ~             ("all your base are belong to us", "allhay ouryay asebay arehay elongbay otay ushay")] {
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: useless use of `vec!`
[INFO] [stdout]    --> chp8/piglatin.rs:143:36
[INFO] [stdout]     |
[INFO] [stdout] 143 |           for (control, expected) in vec![
[INFO] [stdout]     |  ____________________________________^
[INFO] [stdout] 144 | |             ("hello", "ellohay"),
[INFO] [stdout] 145 | |             ("hello world", "ellohay orldway"),
[INFO] [stdout] 146 | |             ("abc today", "abchay odaytay"),
[INFO] [stdout] ...   |
[INFO] [stdout] 149 | |             ("all your\n base are\n belong to us", "allhay ouryay\n asebay arehay\n elongbay otay ushay"),
[INFO] [stdout] 150 | |         ] {
[INFO] [stdout]     | |_________^
[INFO] [stdout]     |
[INFO] [stdout]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_vec
[INFO] [stdout] help: you can use an array directly
[INFO] [stdout]     |
[INFO] [stdout] 143 ~         for (control, expected) in [("hello", "ellohay"),
[INFO] [stdout] 144 +             ("hello world", "ellohay orldway"),
[INFO] [stdout] 145 +             ("abc today", "abchay odaytay"),
[INFO] [stdout] 146 +             ("abc\n today", "abchay\n odaytay"),
[INFO] [stdout] 147 +             ("all your base are belong to us", "allhay ouryay asebay arehay elongbay otay ushay"),
[INFO] [stdout] 148 ~             ("all your\n base are\n belong to us", "allhay ouryay\n asebay arehay\n elongbay otay ushay")] {
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: you seem to be trying to use `match` for destructuring a single pattern. Consider using `if let`
[INFO] [stdout]   --> chp8/company_directory.rs:49:9
[INFO] [stdout]    |
[INFO] [stdout] 49 | /         match io::stdin().read_line(&mut input) {
[INFO] [stdout] 50 | |             Err(e) => {
[INFO] [stdout] 51 | |                 println!("Command error: {:?}", e);
[INFO] [stdout] ...  |
[INFO] [stdout] 54 | |         }
[INFO] [stdout]    | |_________^
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#single_match
[INFO] [stdout]    = note: `#[warn(clippy::single_match)]` on by default
[INFO] [stdout] help: try
[INFO] [stdout]    |
[INFO] [stdout] 49 ~         if let Err(e) = io::stdin().read_line(&mut input) {
[INFO] [stdout] 50 +             println!("Command error: {:?}", e);
[INFO] [stdout] 51 +         }
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unneeded `return` statement
[INFO] [stdout]   --> chp8/company_directory.rs:71:5
[INFO] [stdout]    |
[INFO] [stdout] 71 |     return out;
[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] 71 -     return out;
[INFO] [stdout] 71 +     out
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: length comparison to zero
[INFO] [stdout]   --> chp8/company_directory.rs:90:12
[INFO] [stdout]    |
[INFO] [stdout] 90 |         if args.len() == 0 {
[INFO] [stdout]    |            ^^^^^^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `args.is_empty()`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#len_zero
[INFO] [stdout]    = note: `#[warn(clippy::len_zero)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: length comparison to zero
[INFO] [stdout]    --> chp8/company_directory.rs:128:24
[INFO] [stdout]     |
[INFO] [stdout] 128 |                     if depts.len() == 0 {
[INFO] [stdout]     |                        ^^^^^^^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `depts.is_empty()`
[INFO] [stdout]     |
[INFO] [stdout]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#len_zero
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the following explicit lifetimes could be elided: 'b
[INFO] [stdout]    --> chp8/company_directory.rs:170:21
[INFO] [stdout]     |
[INFO] [stdout] 170 | fn add_dept_emp<'a, 'b>(dept_name: &'a str, emp_name: &'a str, dir: &'b mut Directory) {
[INFO] [stdout]     |                     ^^                                               ^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
[INFO] [stdout]     = note: `#[warn(clippy::needless_lifetimes)]` on by default
[INFO] [stdout] help: elide the lifetimes
[INFO] [stdout]     |
[INFO] [stdout] 170 - fn add_dept_emp<'a, 'b>(dept_name: &'a str, emp_name: &'a str, dir: &'b mut Directory) {
[INFO] [stdout] 170 + fn add_dept_emp<'a>(dept_name: &'a str, emp_name: &'a str, dir: &mut Directory) {
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of `or_insert` to construct default value
[INFO] [stdout]    --> chp8/company_directory.rs:171:47
[INFO] [stdout]     |
[INFO] [stdout] 171 |     dir.listings.entry(dept_name.to_string()).or_insert(HashSet::new())
[INFO] [stdout]     |                                               ^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `or_default()`
[INFO] [stdout]     |
[INFO] [stdout]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unwrap_or_default
[INFO] [stdout]     = note: `#[warn(clippy::unwrap_or_default)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: writing `&String` instead of `&str` involves a new object where a slice will do
[INFO] [stdout]  --> chp2/guessing_game_lib.rs:1:41
[INFO] [stdout]   |
[INFO] [stdout] 1 | pub fn head_after_trim_and_to_lower(xs: &String) -> Option<char> {
[INFO] [stdout]   |                                         ^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#ptr_arg
[INFO] [stdout]   = note: `#[warn(clippy::ptr_arg)]` on by default
[INFO] [stdout] help: change this to
[INFO] [stdout]   |
[INFO] [stdout] 1 - pub fn head_after_trim_and_to_lower(xs: &String) -> Option<char> {
[INFO] [stdout] 1 + pub fn head_after_trim_and_to_lower(xs: &str) -> Option<char> {
[INFO] [stdout]   |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: match expression looks like `matches!` macro
[INFO] [stdout]   --> chp2/guessing_game_lib.rs:17:5
[INFO] [stdout]    |
[INFO] [stdout] 17 | /     match c {
[INFO] [stdout] 18 | |         'y' | ' ' => true,
[INFO] [stdout] 19 | |         _ => false
[INFO] [stdout] 20 | |     }
[INFO] [stdout]    | |_____^
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_like_matches_macro
[INFO] [stdout]    = note: `#[warn(clippy::match_like_matches_macro)]` on by default
[INFO] [stdout] help: use `matches!` directly
[INFO] [stdout]    |
[INFO] [stdout] 17 -     match c {
[INFO] [stdout] 18 -         'y' | ' ' => true,
[INFO] [stdout] 19 -         _ => false
[INFO] [stdout] 20 -     }
[INFO] [stdout] 17 +     matches!(c, 'y' | ' ')
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unneeded `return` statement
[INFO] [stdout]   --> chp2/guessing_game_lib.rs:25:5
[INFO] [stdout]    |
[INFO] [stdout] 25 |     return num;
[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] 25 -     return num;
[INFO] [stdout] 25 +     num
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: empty line after doc comment
[INFO] [stdout]  --> chp3/fib_lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | / /**
[INFO] [stdout] 2 | |  * @reference https://www.goldennumber.net/math/
[INFO] [stdout] 3 | |  */
[INFO] [stdout] 4 | |
[INFO] [stdout]   | |_^
[INFO] [stdout] 5 |   static FIVE_O: f64 = 5.0;
[INFO] [stdout]   |   ------------- the comment documents this static item
[INFO] [stdout]   |
[INFO] [stdout]   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#empty_line_after_doc_comments
[INFO] [stdout]   = note: `#[warn(clippy::empty_line_after_doc_comments)]` on by default
[INFO] [stdout]   = help: if the empty line is unintentional, remove it
[INFO] [stdout] help: if the comment should document the parent module use an inner doc comment
[INFO] [stdout]   |
[INFO] [stdout] 1 - /**
[INFO] [stdout] 1 + /*!
[INFO] [stdout]   |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::thread::JoinHandle`
[INFO] [stdout]  --> chp16/chp16_1.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::thread::JoinHandle;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::thread::JoinHandle`
[INFO] [stdout]  --> chp16/chp16_1.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::thread::JoinHandle;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::collections::HashMap`
[INFO] [stdout]    --> chp8/company_directory.rs:178:9
[INFO] [stdout]     |
[INFO] [stdout] 178 |     use std::collections::HashMap;
[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 import is redundant
[INFO] [stdout]  --> chp2/guessing_game.rs:4:1
[INFO] [stdout]   |
[INFO] [stdout] 4 | use rand;
[INFO] [stdout]   | ^^^^^^^^^ help: remove it entirely
[INFO] [stdout]   |
[INFO] [stdout]   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#single_component_path_imports
[INFO] [stdout]   = note: `#[warn(clippy::single_component_path_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `maximum` is never used
[INFO] [stdout]   --> chp8/main.rs:45:4
[INFO] [stdout]    |
[INFO] [stdout] 45 | fn maximum<T: Ord + Debug>(xs: &Vec<T>) -> Option<&T> {
[INFO] [stdout]    |    ^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unneeded `return` statement
[INFO] [stdout]   --> chp8/main.rs:42:5
[INFO] [stdout]    |
[INFO] [stdout] 42 |     return out;
[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] 42 -     return out;
[INFO] [stdout] 42 +     out
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unneeded `return` statement
[INFO] [stdout]   --> chp8/main.rs:55:5
[INFO] [stdout]    |
[INFO] [stdout] 55 |     return Some(last);
[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] help: remove `return`
[INFO] [stdout]    |
[INFO] [stdout] 55 -     return Some(last);
[INFO] [stdout] 55 +     Some(last)
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: writing `&Vec` instead of `&[_]` involves a new object where a slice will do
[INFO] [stdout]   --> chp8/main.rs:45:32
[INFO] [stdout]    |
[INFO] [stdout] 45 | fn maximum<T: Ord + Debug>(xs: &Vec<T>) -> Option<&T> {
[INFO] [stdout]    |                                ^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#ptr_arg
[INFO] [stdout]    = note: `#[warn(clippy::ptr_arg)]` on by default
[INFO] [stdout] help: change this to
[INFO] [stdout]    |
[INFO] [stdout] 45 - fn maximum<T: Ord + Debug>(xs: &Vec<T>) -> Option<&T> {
[INFO] [stdout] 45 + fn maximum<T: Ord + Debug>(xs: &[T]) -> Option<&T> {
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: length comparison to zero
[INFO] [stdout]   --> chp8/main.rs:46:8
[INFO] [stdout]    |
[INFO] [stdout] 46 |     if xs.len() == 0 {
[INFO] [stdout]    |        ^^^^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `xs.is_empty()`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#len_zero
[INFO] [stdout]    = note: `#[warn(clippy::len_zero)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: this pattern reimplements `Option::unwrap_or`
[INFO] [stdout]   --> chp2/guessing_game_lib.rs:49:26
[INFO] [stdout]    |
[INFO] [stdout] 49 |               let result = match head_after_trim_and_to_lower(&String::from(t.0)) {
[INFO] [stdout]    |  __________________________^
[INFO] [stdout] 50 | |                 Some(x) => x,
[INFO] [stdout] 51 | |                 _ => ' '
[INFO] [stdout] 52 | |             };
[INFO] [stdout]    | |_____________^ help: replace with: `head_after_trim_and_to_lower(&String::from(t.0)).unwrap_or(' ')`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#manual_unwrap_or
[INFO] [stdout]    = note: `#[warn(clippy::manual_unwrap_or)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: writing `&String` instead of `&str` involves a new object where a slice will do
[INFO] [stdout]  --> chp2/guessing_game_lib.rs:1:41
[INFO] [stdout]   |
[INFO] [stdout] 1 | pub fn head_after_trim_and_to_lower(xs: &String) -> Option<char> {
[INFO] [stdout]   |                                         ^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#ptr_arg
[INFO] [stdout]   = note: `#[warn(clippy::ptr_arg)]` on by default
[INFO] [stdout] help: change this to
[INFO] [stdout]   |
[INFO] [stdout] 1 - pub fn head_after_trim_and_to_lower(xs: &String) -> Option<char> {
[INFO] [stdout] 1 + pub fn head_after_trim_and_to_lower(xs: &str) -> Option<char> {
[INFO] [stdout]   |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: match expression looks like `matches!` macro
[INFO] [stdout]   --> chp2/guessing_game_lib.rs:17:5
[INFO] [stdout]    |
[INFO] [stdout] 17 | /     match c {
[INFO] [stdout] 18 | |         'y' | ' ' => true,
[INFO] [stdout] 19 | |         _ => false
[INFO] [stdout] 20 | |     }
[INFO] [stdout]    | |_____^
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_like_matches_macro
[INFO] [stdout]    = note: `#[warn(clippy::match_like_matches_macro)]` on by default
[INFO] [stdout] help: use `matches!` directly
[INFO] [stdout]    |
[INFO] [stdout] 17 -     match c {
[INFO] [stdout] 18 -         'y' | ' ' => true,
[INFO] [stdout] 19 -         _ => false
[INFO] [stdout] 20 -     }
[INFO] [stdout] 17 +     matches!(c, 'y' | ' ')
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: empty line after doc comment
[INFO] [stdout]  --> chp3/fib_lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | / /**
[INFO] [stdout] 2 | |  * @reference https://www.goldennumber.net/math/
[INFO] [stdout] 3 | |  */
[INFO] [stdout] 4 | |
[INFO] [stdout]   | |_^
[INFO] [stdout] 5 |   static FIVE_O: f64 = 5.0;
[INFO] [stdout]   |   ------------- the comment documents this static item
[INFO] [stdout]   |
[INFO] [stdout]   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#empty_line_after_doc_comments
[INFO] [stdout]   = note: `#[warn(clippy::empty_line_after_doc_comments)]` on by default
[INFO] [stdout]   = help: if the empty line is unintentional, remove it
[INFO] [stdout] help: if the comment should document the parent module use an inner doc comment
[INFO] [stdout]   |
[INFO] [stdout] 1 - /**
[INFO] [stdout] 1 + /*!
[INFO] [stdout]   |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: empty line after doc comment
[INFO] [stdout]  --> chp8/piglatin.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | / /**
[INFO] [stdout] 2 | |  * Convert strings to pig latin.
[INFO] [stdout] 3 | |  * The first consonant of each word is moved to the end of the word and “ay” is added, so “first” becomes “irst-fay”.
[INFO] [stdout] 4 | |  * Words that start with a vowel have “hay” added to the end instead (“apple” becomes “apple-hay”).
[INFO] [stdout] 5 | |  * Keep in mind the details about UTF-8 encoding!
[INFO] [stdout] 6 | |  */
[INFO] [stdout] 7 | |
[INFO] [stdout]   | |_^
[INFO] [stdout] 8 |   use std::env;
[INFO] [stdout]   |   - the comment documents this `use` import
[INFO] [stdout]   |
[INFO] [stdout]   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#empty_line_after_doc_comments
[INFO] [stdout]   = note: `#[warn(clippy::empty_line_after_doc_comments)]` on by default
[INFO] [stdout]   = help: if the empty line is unintentional, remove it
[INFO] [stdout] help: if the comment should document the crate use an inner doc comment
[INFO] [stdout]   |
[INFO] [stdout] 1 - /**
[INFO] [stdout] 1 + /*!
[INFO] [stdout]   |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unneeded `return` statement
[INFO] [stdout]   --> chp2/guessing_game_lib.rs:25:5
[INFO] [stdout]    |
[INFO] [stdout] 25 |     return num;
[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] 25 -     return num;
[INFO] [stdout] 25 +     num
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unneeded `return` statement
[INFO] [stdout]   --> chp2/guessing_game.rs:34:5
[INFO] [stdout]    |
[INFO] [stdout] 34 |     return guess
[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] help: remove `return`
[INFO] [stdout]    |
[INFO] [stdout] 34 -     return guess
[INFO] [stdout] 34 +     guess
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: you seem to be trying to use `match` for destructuring a single pattern. Consider using `if let`
[INFO] [stdout]   --> chp2/guessing_game.rs:26:9
[INFO] [stdout]    |
[INFO] [stdout] 26 | /         match io::stdin().read_line(&mut guess) {
[INFO] [stdout] 27 | |             Err(e) => {
[INFO] [stdout] 28 | |                 println!("Only numbers allowed.  Err: {:?}", e);
[INFO] [stdout] ...  |
[INFO] [stdout] 31 | |         }
[INFO] [stdout]    | |_________^
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#single_match
[INFO] [stdout]    = note: `#[warn(clippy::single_match)]` on by default
[INFO] [stdout] help: try
[INFO] [stdout]    |
[INFO] [stdout] 26 ~         if let Err(e) = io::stdin().read_line(&mut guess) {
[INFO] [stdout] 27 +             println!("Only numbers allowed.  Err: {:?}", e);
[INFO] [stdout] 28 +         }
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: equality checks against false can be replaced by a negation
[INFO] [stdout]   --> chp2/guessing_game.rs:66:11
[INFO] [stdout]    |
[INFO] [stdout] 66 |     while is_correct_guess == false && remaining_num_guesses > 0 {
[INFO] [stdout]    |           ^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `!is_correct_guess`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#bool_comparison
[INFO] [stdout]    = note: `#[warn(clippy::bool_comparison)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: equality checks against false can be replaced by a negation
[INFO] [stdout]   --> chp2/guessing_game.rs:88:11
[INFO] [stdout]    |
[INFO] [stdout] 88 |     while quit_game == false {
[INFO] [stdout]    |           ^^^^^^^^^^^^^^^^^^ help: try: `!quit_game`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#bool_comparison
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: this pattern reimplements `Option::unwrap_or`
[INFO] [stdout]    --> chp2/guessing_game_lib.rs:106:24
[INFO] [stdout]     |
[INFO] [stdout] 106 |               let subj = match head_after_trim_and_to_lower(&String::from(*s)) {
[INFO] [stdout]     |  ________________________^
[INFO] [stdout] 107 | |                 Some(x) => x,
[INFO] [stdout] 108 | |                 _ => ' '
[INFO] [stdout] 109 | |             };
[INFO] [stdout]     | |_____________^ help: replace with: `head_after_trim_and_to_lower(&String::from(*s)).unwrap_or(' ')`
[INFO] [stdout]     |
[INFO] [stdout]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#manual_unwrap_or
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unneeded `return` statement
[INFO] [stdout]   --> chp2/guessing_game.rs:34:5
[INFO] [stdout]    |
[INFO] [stdout] 34 |     return guess
[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] help: remove `return`
[INFO] [stdout]    |
[INFO] [stdout] 34 -     return guess
[INFO] [stdout] 34 +     guess
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unneeded `return` statement
[INFO] [stdout]   --> chp8/piglatin.rs:57:5
[INFO] [stdout]    |
[INFO] [stdout] 57 |     return s.to_string();
[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] 57 -     return s.to_string();
[INFO] [stdout] 57 +     s.to_string()
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: length comparison to zero
[INFO] [stdout]   --> chp8/piglatin.rs:34:8
[INFO] [stdout]    |
[INFO] [stdout] 34 |     if s.len() == 0 {
[INFO] [stdout]    |        ^^^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `s.is_empty()`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#len_zero
[INFO] [stdout]    = note: `#[warn(clippy::len_zero)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: you seem to be trying to use `match` for destructuring a single pattern. Consider using `if let`
[INFO] [stdout]   --> chp2/guessing_game.rs:26:9
[INFO] [stdout]    |
[INFO] [stdout] 26 | /         match io::stdin().read_line(&mut guess) {
[INFO] [stdout] 27 | |             Err(e) => {
[INFO] [stdout] 28 | |                 println!("Only numbers allowed.  Err: {:?}", e);
[INFO] [stdout] ...  |
[INFO] [stdout] 31 | |         }
[INFO] [stdout]    | |_________^
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#single_match
[INFO] [stdout]    = note: `#[warn(clippy::single_match)]` on by default
[INFO] [stdout] help: try
[INFO] [stdout]    |
[INFO] [stdout] 26 ~         if let Err(e) = io::stdin().read_line(&mut guess) {
[INFO] [stdout] 27 +             println!("Only numbers allowed.  Err: {:?}", e);
[INFO] [stdout] 28 +         }
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unneeded `return` statement
[INFO] [stdout]   --> chp8/piglatin.rs:72:5
[INFO] [stdout]    |
[INFO] [stdout] 72 |     return out;
[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] help: remove `return`
[INFO] [stdout]    |
[INFO] [stdout] 72 -     return out;
[INFO] [stdout] 72 +     out
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the variable `i` is used as a loop counter
[INFO] [stdout]   --> chp8/piglatin.rs:65:5
[INFO] [stdout]    |
[INFO] [stdout] 65 |     for word in words  {
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^ help: consider using: `for (i, word) in words.into_iter().enumerate()`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#explicit_counter_loop
[INFO] [stdout]    = note: `#[warn(clippy::explicit_counter_loop)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unneeded `return` statement
[INFO] [stdout]   --> chp8/piglatin.rs:87:5
[INFO] [stdout]    |
[INFO] [stdout] 87 |     return out;
[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] help: remove `return`
[INFO] [stdout]    |
[INFO] [stdout] 87 -     return out;
[INFO] [stdout] 87 +     out
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the variable `i` is used as a loop counter
[INFO] [stdout]   --> chp8/piglatin.rs:80:5
[INFO] [stdout]    |
[INFO] [stdout] 80 |     for line in lines {
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^ help: consider using: `for (i, line) in lines.into_iter().enumerate()`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#explicit_counter_loop
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: equality checks against false can be replaced by a negation
[INFO] [stdout]   --> chp2/guessing_game.rs:66:11
[INFO] [stdout]    |
[INFO] [stdout] 66 |     while is_correct_guess == false && remaining_num_guesses > 0 {
[INFO] [stdout]    |           ^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `!is_correct_guess`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#bool_comparison
[INFO] [stdout]    = note: `#[warn(clippy::bool_comparison)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: this boolean expression can be simplified
[INFO] [stdout]   --> chp12/minigrep.rs:17:31
[INFO] [stdout]    |
[INFO] [stdout] 17 |         let case_insensitve = !env::var("CASE_INSENSITIVE").is_err();
[INFO] [stdout]    |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `env::var("CASE_INSENSITIVE").is_ok()`
[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: manual implementation of an assign operation
[INFO] [stdout]   --> chp3/fib_lib.rs:25:9
[INFO] [stdout]    |
[INFO] [stdout] 25 |         a = a + b;
[INFO] [stdout]    |         ^^^^^^^^^ help: replace it with: `a += b`
[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: manual implementation of an assign operation
[INFO] [stdout]   --> chp3/fib_lib.rs:26:9
[INFO] [stdout]    |
[INFO] [stdout] 26 |         b = a + b;
[INFO] [stdout]    |         ^^^^^^^^^ help: replace it with: `b += a`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#assign_op_pattern
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unneeded `return` statement
[INFO] [stdout]   --> chp3/fib_lib.rs:37:5
[INFO] [stdout]    |
[INFO] [stdout] 37 |     return 0;
[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] 37 -     return 0;
[INFO] [stdout] 37 +     0
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the variable `i` is used as a loop counter
[INFO] [stdout]   --> chp3/fib_lib.rs:50:9
[INFO] [stdout]    |
[INFO] [stdout] 50 |         for n in test_cases.iter() {
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `for (i, n) in test_cases.iter().enumerate()`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#explicit_counter_loop
[INFO] [stdout]    = note: `#[warn(clippy::explicit_counter_loop)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the variable `i` is used as a loop counter
[INFO] [stdout]   --> chp3/fib_lib.rs:72:13
[INFO] [stdout]    |
[INFO] [stdout] 72 |             for n2 in result.iter() {
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `for (i, n2) in result.iter().enumerate()`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#explicit_counter_loop
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: equality checks against false can be replaced by a negation
[INFO] [stdout]   --> chp12/minigrep.rs:47:19
[INFO] [stdout]    |
[INFO] [stdout] 47 |     let rslt = if cfg.case_insensitve == false {
[INFO] [stdout]    |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `!cfg.case_insensitve`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#bool_comparison
[INFO] [stdout]    = note: `#[warn(clippy::bool_comparison)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: equality checks against false can be replaced by a negation
[INFO] [stdout]   --> chp2/guessing_game.rs:88:11
[INFO] [stdout]    |
[INFO] [stdout] 88 |     while quit_game == false {
[INFO] [stdout]    |           ^^^^^^^^^^^^^^^^^^ help: try: `!quit_game`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#bool_comparison
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: this boolean expression can be simplified
[INFO] [stdout]   --> chp12/minigrep.rs:17:31
[INFO] [stdout]    |
[INFO] [stdout] 17 |         let case_insensitve = !env::var("CASE_INSENSITIVE").is_err();
[INFO] [stdout]    |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `env::var("CASE_INSENSITIVE").is_ok()`
[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: equality checks against false can be replaced by a negation
[INFO] [stdout]   --> chp12/minigrep.rs:47:19
[INFO] [stdout]    |
[INFO] [stdout] 47 |     let rslt = if cfg.case_insensitve == false {
[INFO] [stdout]    |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `!cfg.case_insensitve`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#bool_comparison
[INFO] [stdout]    = note: `#[warn(clippy::bool_comparison)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: manual implementation of an assign operation
[INFO] [stdout]   --> chp3/fib_lib.rs:25:9
[INFO] [stdout]    |
[INFO] [stdout] 25 |         a = a + b;
[INFO] [stdout]    |         ^^^^^^^^^ help: replace it with: `a += b`
[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: manual implementation of an assign operation
[INFO] [stdout]   --> chp3/fib_lib.rs:26:9
[INFO] [stdout]    |
[INFO] [stdout] 26 |         b = a + b;
[INFO] [stdout]    |         ^^^^^^^^^ help: replace it with: `b += a`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#assign_op_pattern
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unneeded `return` statement
[INFO] [stdout]   --> chp3/fib_lib.rs:37:5
[INFO] [stdout]    |
[INFO] [stdout] 37 |     return 0;
[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] 37 -     return 0;
[INFO] [stdout] 37 +     0
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: name `ADD` contains a capitalized acronym
[INFO] [stdout]   --> chp8/company_directory.rs:13:5
[INFO] [stdout]    |
[INFO] [stdout] 13 |     ADD,
[INFO] [stdout]    |     ^^^ help: consider making the acronym lowercase, except the initial letter: `Add`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#upper_case_acronyms
[INFO] [stdout]    = note: `#[warn(clippy::upper_case_acronyms)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: name `LIST` contains a capitalized acronym
[INFO] [stdout]   --> chp8/company_directory.rs:14:5
[INFO] [stdout]    |
[INFO] [stdout] 14 |     LIST,
[INFO] [stdout]    |     ^^^^ help: consider making the acronym lowercase, except the initial letter: `List`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#upper_case_acronyms
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: name `HELP` contains a capitalized acronym
[INFO] [stdout]   --> chp8/company_directory.rs:15:5
[INFO] [stdout]    |
[INFO] [stdout] 15 |     HELP,
[INFO] [stdout]    |     ^^^^ help: consider making the acronym lowercase, except the initial letter: `Help`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#upper_case_acronyms
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: name `COMMANDS` contains a capitalized acronym
[INFO] [stdout]   --> chp8/company_directory.rs:16:5
[INFO] [stdout]    |
[INFO] [stdout] 16 |     COMMANDS,
[INFO] [stdout]    |     ^^^^^^^^ help: consider making the acronym lowercase, except the initial letter: `Commands`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#upper_case_acronyms
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: name `EXIT` contains a capitalized acronym
[INFO] [stdout]   --> chp8/company_directory.rs:17:5
[INFO] [stdout]    |
[INFO] [stdout] 17 |     EXIT,
[INFO] [stdout]    |     ^^^^ help: consider making the acronym lowercase, except the initial letter: `Exit`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#upper_case_acronyms
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: name `UNKNOWN` contains a capitalized acronym
[INFO] [stdout]   --> chp8/company_directory.rs:18:5
[INFO] [stdout]    |
[INFO] [stdout] 18 |     UNKNOWN
[INFO] [stdout]    |     ^^^^^^^ help: consider making the acronym lowercase, except the initial letter: `Unknown`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#upper_case_acronyms
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unneeded `return` statement
[INFO] [stdout]  --> chp8/mean_and_mode.rs:8:5
[INFO] [stdout]   |
[INFO] [stdout] 8 |     return sum / (v.len() as f64);
[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] 8 -     return sum / (v.len() as f64);
[INFO] [stdout] 8 +     sum / (v.len() as f64)
[INFO] [stdout]   |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: you seem to be trying to use `match` for destructuring a single pattern. Consider using `if let`
[INFO] [stdout]   --> chp8/company_directory.rs:49:9
[INFO] [stdout]    |
[INFO] [stdout] 49 | /         match io::stdin().read_line(&mut input) {
[INFO] [stdout] 50 | |             Err(e) => {
[INFO] [stdout] 51 | |                 println!("Command error: {:?}", e);
[INFO] [stdout] ...  |
[INFO] [stdout] 54 | |         }
[INFO] [stdout]    | |_________^
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#single_match
[INFO] [stdout]    = note: `#[warn(clippy::single_match)]` on by default
[INFO] [stdout] help: try
[INFO] [stdout]    |
[INFO] [stdout] 49 ~         if let Err(e) = io::stdin().read_line(&mut input) {
[INFO] [stdout] 50 +             println!("Command error: {:?}", e);
[INFO] [stdout] 51 +         }
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unneeded `return` statement
[INFO] [stdout]   --> chp8/company_directory.rs:71:5
[INFO] [stdout]    |
[INFO] [stdout] 71 |     return out;
[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] 71 -     return out;
[INFO] [stdout] 71 +     out
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: length comparison to zero
[INFO] [stdout]   --> chp8/company_directory.rs:90:12
[INFO] [stdout]    |
[INFO] [stdout] 90 |         if args.len() == 0 {
[INFO] [stdout]    |            ^^^^^^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `args.is_empty()`
[INFO] [stdout]    |
[INFO] [stdout]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#len_zero
[INFO] [stdout]    = note: `#[warn(clippy::len_zero)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: length comparison to zero
[INFO] [stdout]    --> chp8/company_directory.rs:128:24
[INFO] [stdout]     |
[INFO] [stdout] 128 |                     if depts.len() == 0 {
[INFO] [stdout]     |                        ^^^^^^^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `depts.is_empty()`
[INFO] [stdout]     |
[INFO] [stdout]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#len_zero
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: panic message is not a string literal
[INFO] [stdout]   --> chp8/mean_and_mode.rs:45:26
[INFO] [stdout]    |
[INFO] [stdout] 45 |         Err(e) => panic!(e)
[INFO] [stdout]    |                          ^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this usage of `panic!()` is deprecated; it will be a hard error in Rust 2021
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/panic-macro-consistency.html>
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/panic-macro-consistency.html>
[INFO] [stdout]    = note: `#[warn(non_fmt_panics)]` (part of `#[warn(rust_2021_compatibility)]`) on by default
[INFO] [stdout] help: add a "{}" format string to `Display` the message
[INFO] [stdout]    |
[INFO] [stdout] 45 |         Err(e) => panic!("{}", e)
[INFO] [stdout]    |                          +++++
[INFO] [stdout] help: or use std::panic::panic_any instead
[INFO] [stdout]    |
[INFO] [stdout] 45 -         Err(e) => panic!(e)
[INFO] [stdout] 45 +         Err(e) => std::panic::panic_any(e)
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the following explicit lifetimes could be elided: 'b
[INFO] [stdout]    --> chp8/company_directory.rs:170:21
[INFO] [stdout]     |
[INFO] [stdout] 170 | fn add_dept_emp<'a, 'b>(dept_name: &'a str, emp_name: &'a str, dir: &'b mut Directory) {
[INFO] [stdout]     |                     ^^                                               ^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
[INFO] [stdout]     = note: `#[warn(clippy::needless_lifetimes)]` on by default
[INFO] [stdout] help: elide the lifetimes
[INFO] [stdout]     |
[INFO] [stdout] 170 - fn add_dept_emp<'a, 'b>(dept_name: &'a str, emp_name: &'a str, dir: &'b mut Directory) {
[INFO] [stdout] 170 + fn add_dept_emp<'a>(dept_name: &'a str, emp_name: &'a str, dir: &mut Directory) {
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of `or_insert` to construct default value
[INFO] [stdout]    --> chp8/company_directory.rs:171:47
[INFO] [stdout]     |
[INFO] [stdout] 171 |     dir.listings.entry(dept_name.to_string()).or_insert(HashSet::new())
[INFO] [stdout]     |                                               ^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `or_default()`
[INFO] [stdout]     |
[INFO] [stdout]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unwrap_or_default
[INFO] [stdout]     = note: `#[warn(clippy::unwrap_or_default)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the variable `i` is used as a loop counter
[INFO] [stdout]    --> chp8/company_directory.rs:188:9
[INFO] [stdout]     |
[INFO] [stdout] 188 |         for d in depts {
[INFO] [stdout]     |         ^^^^^^^^^^^^^^ help: consider using: `for (i, d) in depts.into_iter().enumerate()`
[INFO] [stdout]     |
[INFO] [stdout]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#explicit_counter_loop
[INFO] [stdout]     = note: `#[warn(clippy::explicit_counter_loop)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 5.54s
[INFO] running `Command { std: "docker" "inspect" "2ba1adafae8677e0bb5047eb54270ec54bc7afe5bb19270befe4180dc04520aa", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2ba1adafae8677e0bb5047eb54270ec54bc7afe5bb19270befe4180dc04520aa", kill_on_drop: false }`
[INFO] [stdout] 2ba1adafae8677e0bb5047eb54270ec54bc7afe5bb19270befe4180dc04520aa