[INFO] crate tao-of-rust 0.1.0 is already in cache
[INFO] extracting crate tao-of-rust 0.1.0 into work/ex/pr-58948/sources/master#0f88167f89fffe321590c5148f21b7d51d44388d/reg/tao-of-rust/0.1.0
[INFO] extracting crate tao-of-rust 0.1.0 into work/ex/pr-58948/sources/try#a829e31f924ec11e400e8d0c2fd2c4bb8937ae6b/reg/tao-of-rust/0.1.0
[INFO] validating manifest of tao-of-rust-0.1.0 on toolchain master#0f88167f89fffe321590c5148f21b7d51d44388d
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+0f88167f89fffe321590c5148f21b7d51d44388d-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of tao-of-rust-0.1.0 on toolchain try#a829e31f924ec11e400e8d0c2fd2c4bb8937ae6b
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+a829e31f924ec11e400e8d0c2fd2c4bb8937ae6b-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing tao-of-rust-0.1.0
[INFO] finished frobbing tao-of-rust-0.1.0
[INFO] frobbed toml for tao-of-rust-0.1.0 written to work/ex/pr-58948/sources/master#0f88167f89fffe321590c5148f21b7d51d44388d/reg/tao-of-rust/0.1.0/Cargo.toml
[INFO] started frobbing tao-of-rust-0.1.0
[INFO] finished frobbing tao-of-rust-0.1.0
[INFO] frobbed toml for tao-of-rust-0.1.0 written to work/ex/pr-58948/sources/try#a829e31f924ec11e400e8d0c2fd2c4bb8937ae6b/reg/tao-of-rust/0.1.0/Cargo.toml
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+0f88167f89fffe321590c5148f21b7d51d44388d-alt" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+a829e31f924ec11e400e8d0c2fd2c4bb8937ae6b-alt" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+0f88167f89fffe321590c5148f21b7d51d44388d-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+a829e31f924ec11e400e8d0c2fd2c4bb8937ae6b-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] checking tao-of-rust-0.1.0 against try#a829e31f924ec11e400e8d0c2fd2c4bb8937ae6b for pr-58948
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/pr-58948/worker-4/try#a829e31f924ec11e400e8d0c2fd2c4bb8937ae6b:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/pr-58948/sources/try#a829e31f924ec11e400e8d0c2fd2c4bb8937ae6b/reg/tao-of-rust/0.1.0:/opt/crater/workdir:ro,Z" "-v" "/mnt/big/crater/work/local/cargo-home:/opt/crater/cargo-home:ro,Z" "-v" "/mnt/big/crater/work/local/rustup-home:/opt/crater/rustup-home:ro,Z" "-e" "USER_ID=1000" "-e" "SOURCE_DIR=/opt/crater/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/crater/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/crater/cargo-home" "-e" "RUSTUP_HOME=/opt/crater/rustup-home" "-w" "/opt/crater/workdir" "-m" "1536M" "--network" "none" "rustops/crates-build-env" "/opt/crater/cargo-home/bin/cargo" "+a829e31f924ec11e400e8d0c2fd2c4bb8937ae6b-alt" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] 0b8d28f155c1134ff2221295f5f7c4e5c6a1817e806d9c741c5582f47acc9864
[INFO] running `"docker" "start" "-a" "0b8d28f155c1134ff2221295f5f7c4e5c6a1817e806d9c741c5582f47acc9864"`
[INFO] [stderr]     Checking csv_challenge v0.1.0
[INFO] [stderr]     Checking failures_crate v0.1.0
[INFO] [stderr]     Checking tao-of-rust v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: unnecessary parentheses around `for` head expression
[INFO] [stderr]    --> src/ch2/primitives.rs:170:14
[INFO] [stderr]     |
[INFO] [stderr] 170 |     for i in (1..5) {
[INFO] [stderr]     |              ^^^^^^ help: remove these parentheses
[INFO] [stderr]     |
[INFO] [stderr]     = note: #[warn(unused_parens)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unnecessary parentheses around `for` head expression
[INFO] [stderr]    --> src/ch2/primitives.rs:173:14
[INFO] [stderr]     |
[INFO] [stderr] 173 |     for i in (1..=5) {
[INFO] [stderr]     |              ^^^^^^^ help: remove these parentheses
[INFO] [stderr] 
[INFO] [stderr] warning: unnecessary parentheses around `if` condition
[INFO] [stderr]   --> src/ch2/structs.rs:58:23
[INFO] [stderr]    |
[INFO] [stderr] 58 |       let gender = if (self.gender == 1) {"boy"} else {"girl"};
[INFO] [stderr]    |                       ^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stderr] 
[INFO] [stderr] warning: unnecessary parentheses around `for` head expression
[INFO] [stderr]    --> src/ch2/primitives.rs:170:14
[INFO] [stderr]     |
[INFO] [stderr] 170 |     for i in (1..5) {
[INFO] [stderr]     |              ^^^^^^ help: remove these parentheses
[INFO] [stderr]     |
[INFO] [stderr]     = note: #[warn(unused_parens)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unnecessary parentheses around `for` head expression
[INFO] [stderr]    --> src/ch2/primitives.rs:173:14
[INFO] [stderr]     |
[INFO] [stderr] 173 |     for i in (1..=5) {
[INFO] [stderr]     |              ^^^^^^^ help: remove these parentheses
[INFO] [stderr] 
[INFO] [stderr] warning: unnecessary parentheses around `if` condition
[INFO] [stderr]   --> src/ch2/structs.rs:58:23
[INFO] [stderr]    |
[INFO] [stderr] 58 |       let gender = if (self.gender == 1) {"boy"} else {"girl"};
[INFO] [stderr]    |                       ^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `a`
[INFO] [stderr]   --> src/ch2/binding.rs:31:9
[INFO] [stderr]    |
[INFO] [stderr] 31 |     let a = 1;
[INFO] [stderr]    |         ^ help: consider prefixing with an underscore: `_a`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_variables)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable `b` is assigned to, but never used
[INFO] [stderr]   --> src/ch2/binding.rs:33:13
[INFO] [stderr]    |
[INFO] [stderr] 33 |     let mut b = 2;
[INFO] [stderr]    |             ^
[INFO] [stderr]    |
[INFO] [stderr]    = note: consider using `_b` instead
[INFO] [stderr] 
[INFO] [stderr] warning: value assigned to `b` is never read
[INFO] [stderr]   --> src/ch2/binding.rs:34:5
[INFO] [stderr]    |
[INFO] [stderr] 34 |     b = 3; // mutable
[INFO] [stderr]    |     ^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_assignments)] on by default
[INFO] [stderr]    = help: maybe it is overwritten before being read?
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `v2`
[INFO] [stderr]   --> src/ch2/collections.rs:31:13
[INFO] [stderr]    |
[INFO] [stderr] 31 |     let mut v2 = vec![0; 10];
[INFO] [stderr]    |             ^^ help: consider prefixing with an underscore: `_v2`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `x`
[INFO] [stderr]   --> src/ch2/primitives.rs:17:9
[INFO] [stderr]    |
[INFO] [stderr] 17 |     let x = true;
[INFO] [stderr]    |         ^ help: consider prefixing with an underscore: `_x`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `num`
[INFO] [stderr]   --> src/ch2/primitives.rs:52:9
[INFO] [stderr]    |
[INFO] [stderr] 52 |     let num = 42u32;
[INFO] [stderr]    |         ^^^ help: consider prefixing with an underscore: `_num`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `num`
[INFO] [stderr]   --> src/ch2/primitives.rs:53:9
[INFO] [stderr]    |
[INFO] [stderr] 53 |     let num: u32 = 42;
[INFO] [stderr]    |         ^^^ help: consider prefixing with an underscore: `_num`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `num`
[INFO] [stderr]   --> src/ch2/primitives.rs:54:9
[INFO] [stderr]    |
[INFO] [stderr] 54 |     let num = 0x2A;  // 16进制
[INFO] [stderr]    |         ^^^ help: consider prefixing with an underscore: `_num`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `num`
[INFO] [stderr]   --> src/ch2/primitives.rs:55:9
[INFO] [stderr]    |
[INFO] [stderr] 55 |     let num = 0o106;  // 8进制
[INFO] [stderr]    |         ^^^ help: consider prefixing with an underscore: `_num`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `num`
[INFO] [stderr]   --> src/ch2/primitives.rs:56:9
[INFO] [stderr]    |
[INFO] [stderr] 56 |     let num = 0b1101_1011; // 2进制
[INFO] [stderr]    |         ^^^ help: consider prefixing with an underscore: `_num`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `num`
[INFO] [stderr]   --> src/ch2/primitives.rs:59:9
[INFO] [stderr]    |
[INFO] [stderr] 59 |     let num = 3.1415926f64;
[INFO] [stderr]    |         ^^^ help: consider prefixing with an underscore: `_num`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `x`
[INFO] [stderr]   --> src/ch2/primitives.rs:94:9
[INFO] [stderr]    |
[INFO] [stderr] 94 |     let x = 'r';
[INFO] [stderr]    |         ^ help: consider prefixing with an underscore: `_x`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `x`
[INFO] [stderr]   --> src/ch2/primitives.rs:95:9
[INFO] [stderr]    |
[INFO] [stderr] 95 |     let x = 'Ú';
[INFO] [stderr]    |         ^ help: consider prefixing with an underscore: `_x`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `arr`
[INFO] [stderr]    --> src/ch2/primitives.rs:128:9
[INFO] [stderr]     |
[INFO] [stderr] 128 |     let arr: [i32; 3] = [1, 2, 3];
[INFO] [stderr]     |         ^^^ help: consider prefixing with an underscore: `_arr`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `x`
[INFO] [stderr]    --> src/ch2/primitives.rs:350:9
[INFO] [stderr]     |
[INFO] [stderr] 350 |     let x: ! = {
[INFO] [stderr]     |         ^ help: consider prefixing with an underscore: `_x`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `p`
[INFO] [stderr]    --> src/ch3/traits.rs:246:28
[INFO] [stderr]     |
[INFO] [stderr] 246 |         fn set_page(&self, p: i32){
[INFO] [stderr]     |                            ^ help: consider prefixing with an underscore: `_p`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `num`
[INFO] [stderr]    --> src/ch3/traits.rs:251:31
[INFO] [stderr]     |
[INFO] [stderr] 251 |         fn set_perpage(&self, num: i32){
[INFO] [stderr]     |                               ^^^ help: consider prefixing with an underscore: `_num`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `i`
[INFO] [stderr]   --> src/ch3/tag_trait.rs:53:27
[INFO] [stderr]    |
[INFO] [stderr] 53 |     fn test_copy<T: Copy>(i: T) {
[INFO] [stderr]    |                           ^ help: consider prefixing with an underscore: `_i`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `y`
[INFO] [stderr]   --> src/ch3/type_cast.rs:71:9
[INFO] [stderr]    |
[INFO] [stderr] 71 |     let y = x.clone();  // Rc<&str>
[INFO] [stderr]    |         ^ help: consider prefixing with an underscore: `_y`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `z`
[INFO] [stderr]   --> src/ch3/type_cast.rs:72:9
[INFO] [stderr]    |
[INFO] [stderr] 72 |     let z = (*x).clone();   // &str
[INFO] [stderr]    |         ^ help: consider prefixing with an underscore: `_z`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `y`
[INFO] [stderr]   --> src/ch4/general_concepts.rs:18:13
[INFO] [stderr]    |
[INFO] [stderr] 18 |         let y = x;
[INFO] [stderr]    |             ^ help: consider prefixing with an underscore: `_y`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `z`
[INFO] [stderr]   --> src/ch4/general_concepts.rs:19:13
[INFO] [stderr]    |
[INFO] [stderr] 19 |         let z = 100;
[INFO] [stderr]    |             ^ help: consider prefixing with an underscore: `_z`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `s`
[INFO] [stderr]   --> src/ch4/raii.rs:14:13
[INFO] [stderr]    |
[INFO] [stderr] 14 |         let s = String::from("hello");
[INFO] [stderr]    |             ^ help: consider prefixing with an underscore: `_s`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `v`
[INFO] [stderr]   --> src/ch4/raii.rs:16:13
[INFO] [stderr]    |
[INFO] [stderr] 16 |         let v = vec![1,2,3];
[INFO] [stderr]    |             ^ help: consider prefixing with an underscore: `_v`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `stolen`
[INFO] [stderr]   --> src/ch5/semantic.rs:30:13
[INFO] [stderr]    |
[INFO] [stderr] 30 |         let stolen = orig;
[INFO] [stderr]    |             ^^^^^^ help: consider prefixing with an underscore: `_stolen`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `b`
[INFO] [stderr]    --> src/ch5/semantic.rs:113:13
[INFO] [stderr]     |
[INFO] [stderr] 113 |         let b = a;
[INFO] [stderr]     |             ^ help: consider prefixing with an underscore: `_b`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `x`
[INFO] [stderr]   --> src/ch5/share_mutable.rs:22:13
[INFO] [stderr]    |
[INFO] [stderr] 22 |         let x = "hello".to_string();
[INFO] [stderr]    |             ^ help: consider prefixing with an underscore: `_x`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `a`
[INFO] [stderr]    --> src/ch5/share_mutable.rs:133:13
[INFO] [stderr]     |
[INFO] [stderr] 133 |         let a = "hello";   // -------scope a-------+
[INFO] [stderr]     |             ^ help: consider prefixing with an underscore: `_a`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `b`
[INFO] [stderr]    --> src/ch5/share_mutable.rs:134:13
[INFO] [stderr]     |
[INFO] [stderr] 134 |         let b = "rust";    // -----scope b------+  |
[INFO] [stderr]     |             ^ help: consider prefixing with an underscore: `_b`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `d`
[INFO] [stderr]    --> src/ch5/share_mutable.rs:136:13
[INFO] [stderr]     |
[INFO] [stderr] 136 |         let d = c;         // - scope d ---  |  |  |
[INFO] [stderr]     |             ^ help: consider prefixing with an underscore: `_d`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `args`
[INFO] [stderr]    --> src/ch6/closures.rs:130:47
[INFO] [stderr]     |
[INFO] [stderr] 130 |         extern "rust-call" fn call_once(self, args: ()) -> u32 {
[INFO] [stderr]     |                                               ^^^^ help: consider prefixing with an underscore: `_args`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `args`
[INFO] [stderr]    --> src/ch6/closures.rs:136:51
[INFO] [stderr]     |
[INFO] [stderr] 136 |         extern "rust-call" fn call_mut(&mut self, args: ()) -> u32 {
[INFO] [stderr]     |                                                   ^^^^ help: consider prefixing with an underscore: `_args`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `args`
[INFO] [stderr]    --> src/ch6/closures.rs:142:43
[INFO] [stderr]     |
[INFO] [stderr] 142 |         extern "rust-call" fn call(&self, args: ()) -> u32 {
[INFO] [stderr]     |                                           ^^^^ help: consider prefixing with an underscore: `_args`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/ch2/collections.rs:31:9
[INFO] [stderr]    |
[INFO] [stderr] 31 |     let mut v2 = vec![0; 10];
[INFO] [stderr]    |         ----^^
[INFO] [stderr]    |         |
[INFO] [stderr]    |         help: remove this `mut`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_mut)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `a`
[INFO] [stderr]   --> src/ch2/binding.rs:31:9
[INFO] [stderr]    |
[INFO] [stderr] 31 |     let a = 1;
[INFO] [stderr]    |         ^ help: consider prefixing with an underscore: `_a`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_variables)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable `b` is assigned to, but never used
[INFO] [stderr]   --> src/ch2/binding.rs:33:13
[INFO] [stderr]    |
[INFO] [stderr] 33 |     let mut b = 2;
[INFO] [stderr]    |             ^
[INFO] [stderr]    |
[INFO] [stderr]    = note: consider using `_b` instead
[INFO] [stderr] 
[INFO] [stderr] warning: value assigned to `b` is never read
[INFO] [stderr]   --> src/ch2/binding.rs:34:5
[INFO] [stderr]    |
[INFO] [stderr] 34 |     b = 3; // mutable
[INFO] [stderr]    |     ^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_assignments)] on by default
[INFO] [stderr]    = help: maybe it is overwritten before being read?
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `v2`
[INFO] [stderr]   --> src/ch2/collections.rs:31:13
[INFO] [stderr]    |
[INFO] [stderr] 31 |     let mut v2 = vec![0; 10];
[INFO] [stderr]    |             ^^ help: consider prefixing with an underscore: `_v2`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `x`
[INFO] [stderr]   --> src/ch2/primitives.rs:17:9
[INFO] [stderr]    |
[INFO] [stderr] 17 |     let x = true;
[INFO] [stderr]    |         ^ help: consider prefixing with an underscore: `_x`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `num`
[INFO] [stderr]   --> src/ch2/primitives.rs:52:9
[INFO] [stderr]    |
[INFO] [stderr] 52 |     let num = 42u32;
[INFO] [stderr]    |         ^^^ help: consider prefixing with an underscore: `_num`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `num`
[INFO] [stderr]   --> src/ch2/primitives.rs:53:9
[INFO] [stderr]    |
[INFO] [stderr] 53 |     let num: u32 = 42;
[INFO] [stderr]    |         ^^^ help: consider prefixing with an underscore: `_num`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `num`
[INFO] [stderr]   --> src/ch2/primitives.rs:54:9
[INFO] [stderr]    |
[INFO] [stderr] 54 |     let num = 0x2A;  // 16进制
[INFO] [stderr]    |         ^^^ help: consider prefixing with an underscore: `_num`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `num`
[INFO] [stderr]   --> src/ch2/primitives.rs:55:9
[INFO] [stderr]    |
[INFO] [stderr] 55 |     let num = 0o106;  // 8进制
[INFO] [stderr]    |         ^^^ help: consider prefixing with an underscore: `_num`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `num`
[INFO] [stderr]   --> src/ch2/primitives.rs:56:9
[INFO] [stderr]    |
[INFO] [stderr] 56 |     let num = 0b1101_1011; // 2进制
[INFO] [stderr]    |         ^^^ help: consider prefixing with an underscore: `_num`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `num`
[INFO] [stderr]   --> src/ch2/primitives.rs:59:9
[INFO] [stderr]    |
[INFO] [stderr] 59 |     let num = 3.1415926f64;
[INFO] [stderr]    |         ^^^ help: consider prefixing with an underscore: `_num`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `x`
[INFO] [stderr]   --> src/ch2/primitives.rs:94:9
[INFO] [stderr]    |
[INFO] [stderr] 94 |     let x = 'r';
[INFO] [stderr]    |         ^ help: consider prefixing with an underscore: `_x`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `x`
[INFO] [stderr]   --> src/ch2/primitives.rs:95:9
[INFO] [stderr]    |
[INFO] [stderr] 95 |     let x = 'Ú';
[INFO] [stderr]    |         ^ help: consider prefixing with an underscore: `_x`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `arr`
[INFO] [stderr]    --> src/ch2/primitives.rs:128:9
[INFO] [stderr]     |
[INFO] [stderr] 128 |     let arr: [i32; 3] = [1, 2, 3];
[INFO] [stderr]     |         ^^^ help: consider prefixing with an underscore: `_arr`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `x`
[INFO] [stderr]    --> src/ch2/primitives.rs:350:9
[INFO] [stderr]     |
[INFO] [stderr] 350 |     let x: ! = {
[INFO] [stderr]     |         ^ help: consider prefixing with an underscore: `_x`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `p`
[INFO] [stderr]    --> src/ch3/traits.rs:246:28
[INFO] [stderr]     |
[INFO] [stderr] 246 |         fn set_page(&self, p: i32){
[INFO] [stderr]     |                            ^ help: consider prefixing with an underscore: `_p`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `num`
[INFO] [stderr]    --> src/ch3/traits.rs:251:31
[INFO] [stderr]     |
[INFO] [stderr] 251 |         fn set_perpage(&self, num: i32){
[INFO] [stderr]     |                               ^^^ help: consider prefixing with an underscore: `_num`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `i`
[INFO] [stderr]   --> src/ch3/tag_trait.rs:53:27
[INFO] [stderr]    |
[INFO] [stderr] 53 |     fn test_copy<T: Copy>(i: T) {
[INFO] [stderr]    |                           ^ help: consider prefixing with an underscore: `_i`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `y`
[INFO] [stderr]   --> src/ch3/type_cast.rs:71:9
[INFO] [stderr]    |
[INFO] [stderr] 71 |     let y = x.clone();  // Rc<&str>
[INFO] [stderr]    |         ^ help: consider prefixing with an underscore: `_y`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `z`
[INFO] [stderr]   --> src/ch3/type_cast.rs:72:9
[INFO] [stderr]    |
[INFO] [stderr] 72 |     let z = (*x).clone();   // &str
[INFO] [stderr]    |         ^ help: consider prefixing with an underscore: `_z`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `y`
[INFO] [stderr]   --> src/ch4/general_concepts.rs:18:13
[INFO] [stderr]    |
[INFO] [stderr] 18 |         let y = x;
[INFO] [stderr]    |             ^ help: consider prefixing with an underscore: `_y`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `z`
[INFO] [stderr]   --> src/ch4/general_concepts.rs:19:13
[INFO] [stderr]    |
[INFO] [stderr] 19 |         let z = 100;
[INFO] [stderr]    |             ^ help: consider prefixing with an underscore: `_z`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `s`
[INFO] [stderr]   --> src/ch4/raii.rs:14:13
[INFO] [stderr]    |
[INFO] [stderr] 14 |         let s = String::from("hello");
[INFO] [stderr]    |             ^ help: consider prefixing with an underscore: `_s`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `v`
[INFO] [stderr]   --> src/ch4/raii.rs:16:13
[INFO] [stderr]    |
[INFO] [stderr] 16 |         let v = vec![1,2,3];
[INFO] [stderr]    |             ^ help: consider prefixing with an underscore: `_v`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `stolen`
[INFO] [stderr]   --> src/ch5/semantic.rs:30:13
[INFO] [stderr]    |
[INFO] [stderr] 30 |         let stolen = orig;
[INFO] [stderr]    |             ^^^^^^ help: consider prefixing with an underscore: `_stolen`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `b`
[INFO] [stderr]    --> src/ch5/semantic.rs:113:13
[INFO] [stderr]     |
[INFO] [stderr] 113 |         let b = a;
[INFO] [stderr]     |             ^ help: consider prefixing with an underscore: `_b`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `x`
[INFO] [stderr]   --> src/ch5/share_mutable.rs:22:13
[INFO] [stderr]    |
[INFO] [stderr] 22 |         let x = "hello".to_string();
[INFO] [stderr]    |             ^ help: consider prefixing with an underscore: `_x`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `a`
[INFO] [stderr]    --> src/ch5/share_mutable.rs:133:13
[INFO] [stderr]     |
[INFO] [stderr] 133 |         let a = "hello";   // -------scope a-------+
[INFO] [stderr]     |             ^ help: consider prefixing with an underscore: `_a`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `b`
[INFO] [stderr]    --> src/ch5/share_mutable.rs:134:13
[INFO] [stderr]     |
[INFO] [stderr] 134 |         let b = "rust";    // -----scope b------+  |
[INFO] [stderr]     |             ^ help: consider prefixing with an underscore: `_b`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `d`
[INFO] [stderr]    --> src/ch5/share_mutable.rs:136:13
[INFO] [stderr]     |
[INFO] [stderr] 136 |         let d = c;         // - scope d ---  |  |  |
[INFO] [stderr]     |             ^ help: consider prefixing with an underscore: `_d`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `args`
[INFO] [stderr]    --> src/ch6/closures.rs:130:47
[INFO] [stderr]     |
[INFO] [stderr] 130 |         extern "rust-call" fn call_once(self, args: ()) -> u32 {
[INFO] [stderr]     |                                               ^^^^ help: consider prefixing with an underscore: `_args`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `args`
[INFO] [stderr]    --> src/ch6/closures.rs:136:51
[INFO] [stderr]     |
[INFO] [stderr] 136 |         extern "rust-call" fn call_mut(&mut self, args: ()) -> u32 {
[INFO] [stderr]     |                                                   ^^^^ help: consider prefixing with an underscore: `_args`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `args`
[INFO] [stderr]    --> src/ch6/closures.rs:142:43
[INFO] [stderr]     |
[INFO] [stderr] 142 |         extern "rust-call" fn call(&self, args: ()) -> u32 {
[INFO] [stderr]     |                                           ^^^^ help: consider prefixing with an underscore: `_args`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/ch2/collections.rs:31:9
[INFO] [stderr]    |
[INFO] [stderr] 31 |     let mut v2 = vec![0; 10];
[INFO] [stderr]    |         ----^^
[INFO] [stderr]    |         |
[INFO] [stderr]    |         help: remove this `mut`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_mut)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `sum`
[INFO] [stderr]   --> src/ch2/function.rs:89:1
[INFO] [stderr]    |
[INFO] [stderr] 89 | fn sum(a: i32, b: i32) -> i32 {
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(dead_code)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `product`
[INFO] [stderr]   --> src/ch2/function.rs:92:1
[INFO] [stderr]    |
[INFO] [stderr] 92 | fn product(a: i32, b: i32) -> i32 {
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `map_demo`
[INFO] [stderr]    --> src/ch2/collections.rs:169:1
[INFO] [stderr]     |
[INFO] [stderr] 169 | fn map_demo() {
[INFO] [stderr]     | ^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `foo`
[INFO] [stderr]    --> src/ch2/primitives.rs:349:1
[INFO] [stderr]     |
[INFO] [stderr] 349 | fn foo() -> u32 {
[INFO] [stderr]     | ^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `new`
[INFO] [stderr]   --> src/ch2/structs.rs:48:5
[INFO] [stderr]    |
[INFO] [stderr] 48 |     fn new(name: &'static str, gender: u32) -> Self{
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `name`
[INFO] [stderr]   --> src/ch2/structs.rs:51:5
[INFO] [stderr]    |
[INFO] [stderr] 51 |     fn name(&self) {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `set_name`
[INFO] [stderr]   --> src/ch2/structs.rs:54:5
[INFO] [stderr]    |
[INFO] [stderr] 54 |     fn set_name(&mut self, name: &'static str)  {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `gender`
[INFO] [stderr]   --> src/ch2/structs.rs:57:5
[INFO] [stderr]    |
[INFO] [stderr] 57 |     fn gender(&self){
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: field is never used: `foo`
[INFO] [stderr]   --> src/ch3/zero_size.rs:27:9
[INFO] [stderr]    |
[INFO] [stderr] 27 |         foo: Foo,
[INFO] [stderr]    |         ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: field is never used: `qux`
[INFO] [stderr]   --> src/ch3/zero_size.rs:28:9
[INFO] [stderr]    |
[INFO] [stderr] 28 |         qux: (),
[INFO] [stderr]    |         ^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: field is never used: `baz`
[INFO] [stderr]   --> src/ch3/zero_size.rs:29:9
[INFO] [stderr]    |
[INFO] [stderr] 29 |         baz: [u8; 0],
[INFO] [stderr]    |         ^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: field is never used: `page`
[INFO] [stderr]    --> src/ch3/traits.rs:262:24
[INFO] [stderr]     |
[INFO] [stderr] 262 |     struct MyPaginate{ page: i32 }
[INFO] [stderr]     |                        ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: field is never used: `inner`
[INFO] [stderr]    --> src/ch3/trait_limit.rs:147:9
[INFO] [stderr]     |
[INFO] [stderr] 147 |         inner: T,
[INFO] [stderr]     |         ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `foo`
[INFO] [stderr]   --> src/ch4/general_concepts.rs:17:5
[INFO] [stderr]    |
[INFO] [stderr] 17 |     fn foo(x: u32) {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]   --> src/ch4/general_concepts.rs:21:5
[INFO] [stderr]    |
[INFO] [stderr] 21 |     fn main(){
[INFO] [stderr]    |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `A`
[INFO] [stderr]   --> src/ch4/general_concepts.rs:56:5
[INFO] [stderr]    |
[INFO] [stderr] 56 |     struct A {
[INFO] [stderr]    |     ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]   --> src/ch4/general_concepts.rs:61:5
[INFO] [stderr]    |
[INFO] [stderr] 61 |     fn main() {
[INFO] [stderr]    |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `A`
[INFO] [stderr]   --> src/ch4/general_concepts.rs:96:5
[INFO] [stderr]    |
[INFO] [stderr] 96 |     struct A {
[INFO] [stderr]    |     ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `B`
[INFO] [stderr]    --> src/ch4/general_concepts.rs:100:5
[INFO] [stderr]     |
[INFO] [stderr] 100 |     struct B(i32, f64, char);
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `N`
[INFO] [stderr]    --> src/ch4/general_concepts.rs:101:5
[INFO] [stderr]     |
[INFO] [stderr] 101 |     struct N;
[INFO] [stderr]     |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: enum is never used: `E`
[INFO] [stderr]    --> src/ch4/general_concepts.rs:102:5
[INFO] [stderr]     |
[INFO] [stderr] 102 |     enum E {
[INFO] [stderr]     |     ^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: union is never used: `U`
[INFO] [stderr]    --> src/ch4/general_concepts.rs:106:5
[INFO] [stderr]     |
[INFO] [stderr] 106 |     union U {
[INFO] [stderr]     |     ^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]    --> src/ch4/general_concepts.rs:110:5
[INFO] [stderr]     |
[INFO] [stderr] 110 |     fn main(){
[INFO] [stderr]     |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]   --> src/ch4/resource_management.rs:59:5
[INFO] [stderr]    |
[INFO] [stderr] 59 |     fn main() {
[INFO] [stderr]    |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]   --> src/ch4/raii.rs:13:5
[INFO] [stderr]    |
[INFO] [stderr] 13 |     fn main() {
[INFO] [stderr]    |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `S`
[INFO] [stderr]   --> src/ch4/raii.rs:94:5
[INFO] [stderr]    |
[INFO] [stderr] 94 |     struct S(i32);
[INFO] [stderr]    |     ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]    --> src/ch4/raii.rs:100:5
[INFO] [stderr]     |
[INFO] [stderr] 100 |     fn main() {
[INFO] [stderr]     |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]   --> src/ch5/semantic.rs:27:5
[INFO] [stderr]    |
[INFO] [stderr] 27 |     fn main() {
[INFO] [stderr]    |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]    --> src/ch5/semantic.rs:111:5
[INFO] [stderr]     |
[INFO] [stderr] 111 |     fn main(){
[INFO] [stderr]     |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]   --> src/ch5/share_mutable.rs:21:5
[INFO] [stderr]    |
[INFO] [stderr] 21 |     fn main() {
[INFO] [stderr]    |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]    --> src/ch5/share_mutable.rs:132:5
[INFO] [stderr]     |
[INFO] [stderr] 132 |     fn main(){
[INFO] [stderr]     |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `foo`
[INFO] [stderr]   --> src/ch5/borrow.rs:31:5
[INFO] [stderr]    |
[INFO] [stderr] 31 |     fn foo(mut v: [i32; 3]) -> [i32; 3] {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]   --> src/ch5/borrow.rs:36:5
[INFO] [stderr]    |
[INFO] [stderr] 36 |     fn main() {
[INFO] [stderr]    |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `bubble_sort`
[INFO] [stderr]   --> src/ch5/borrow.rs:73:5
[INFO] [stderr]    |
[INFO] [stderr] 73 |     fn bubble_sort(a: &mut Vec<i32>) {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]   --> src/ch5/borrow.rs:90:5
[INFO] [stderr]    |
[INFO] [stderr] 90 |     fn main() {
[INFO] [stderr]    |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `compute`
[INFO] [stderr]    --> src/ch5/borrow.rs:139:5
[INFO] [stderr]     |
[INFO] [stderr] 139 |     fn compute(input: &u32, output: &mut u32) {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]    --> src/ch5/borrow.rs:147:5
[INFO] [stderr]     |
[INFO] [stderr] 147 |     fn main() {
[INFO] [stderr]     |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]   --> src/ch5/lifetime.rs:16:5
[INFO] [stderr]    |
[INFO] [stderr] 16 |     fn main() {
[INFO] [stderr]    |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]    --> src/ch5/lifetime.rs:239:5
[INFO] [stderr]     |
[INFO] [stderr] 239 |     fn main() {
[INFO] [stderr]     |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `foo`
[INFO] [stderr]    --> src/ch5/nll.rs:117:5
[INFO] [stderr]     |
[INFO] [stderr] 117 |     fn foo<'a>(x: &'a str, y: &'a str) -> &'a str {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]    --> src/ch5/nll.rs:124:5
[INFO] [stderr]     |
[INFO] [stderr] 124 |     fn main(){
[INFO] [stderr]     |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]    --> src/ch5/nll.rs:181:5
[INFO] [stderr]     |
[INFO] [stderr] 181 |     fn main(){
[INFO] [stderr]     |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `modify`
[INFO] [stderr]   --> src/ch6/functions.rs:30:5
[INFO] [stderr]    |
[INFO] [stderr] 30 |     fn modify(mut v: Vec<u32>) -> Vec<u32> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]   --> src/ch6/functions.rs:34:5
[INFO] [stderr]    |
[INFO] [stderr] 34 |     fn main(){
[INFO] [stderr]    |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `f`
[INFO] [stderr]   --> src/ch6/functions.rs:71:5
[INFO] [stderr]    |
[INFO] [stderr] 71 |     fn f() { print!("1"); }
[INFO] [stderr]    |     ^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]   --> src/ch6/functions.rs:72:5
[INFO] [stderr]    |
[INFO] [stderr] 72 |     fn main() {
[INFO] [stderr]    |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `S`
[INFO] [stderr]    --> src/ch6/functions.rs:126:5
[INFO] [stderr]     |
[INFO] [stderr] 126 |     struct S { i: i32 }
[INFO] [stderr]     |     ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `f`
[INFO] [stderr]    --> src/ch6/functions.rs:127:5
[INFO] [stderr]     |
[INFO] [stderr] 127 |     fn f(ref _s: S) {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]    --> src/ch6/functions.rs:130:5
[INFO] [stderr]     |
[INFO] [stderr] 130 |     fn main() {
[INFO] [stderr]     |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `addsub`
[INFO] [stderr]    --> src/ch6/functions.rs:167:5
[INFO] [stderr]     |
[INFO] [stderr] 167 |     fn addsub(x: isize, y: isize) -> (isize, isize) {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]    --> src/ch6/functions.rs:170:5
[INFO] [stderr]     |
[INFO] [stderr] 170 |     fn main(){
[INFO] [stderr]     |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `square`
[INFO] [stderr]    --> src/ch6/functions.rs:210:5
[INFO] [stderr]     |
[INFO] [stderr] 210 |     fn square<T: Mul<T, Output=T>>(x: T, y: T) -> T {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]    --> src/ch6/functions.rs:213:5
[INFO] [stderr]     |
[INFO] [stderr] 213 |     fn main() {
[INFO] [stderr]     |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `User`
[INFO] [stderr]    --> src/ch6/functions.rs:249:5
[INFO] [stderr]     |
[INFO] [stderr] 249 |     struct User {
[INFO] [stderr]     |     ^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `show`
[INFO] [stderr]    --> src/ch6/functions.rs:254:9
[INFO] [stderr]     |
[INFO] [stderr] 254 |         fn show(&self)  {
[INFO] [stderr]     |         ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]    --> src/ch6/functions.rs:259:5
[INFO] [stderr]     |
[INFO] [stderr] 259 |     fn main() {
[INFO] [stderr]     |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `math`
[INFO] [stderr]    --> src/ch6/functions.rs:399:5
[INFO] [stderr]     |
[INFO] [stderr] 399 |     fn math(op: fn(i32, i32) -> i32, a: i32, b: i32) -> i32{
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `sum`
[INFO] [stderr]    --> src/ch6/functions.rs:402:5
[INFO] [stderr]     |
[INFO] [stderr] 402 |     fn sum(a: i32, b: i32) -> i32 {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `product`
[INFO] [stderr]    --> src/ch6/functions.rs:405:5
[INFO] [stderr]     |
[INFO] [stderr] 405 |     fn product(a: i32, b: i32) -> i32 {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]    --> src/ch6/functions.rs:408:5
[INFO] [stderr]     |
[INFO] [stderr] 408 |     fn main() {
[INFO] [stderr]     |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `counter`
[INFO] [stderr]   --> src/ch6/closures.rs:48:5
[INFO] [stderr]    |
[INFO] [stderr] 48 |     fn counter(i: i32) -> Box<Fn(i32) -> i32> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]   --> src/ch6/closures.rs:51:5
[INFO] [stderr]    |
[INFO] [stderr] 51 |     fn main() {
[INFO] [stderr]    |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `Closure`
[INFO] [stderr]    --> src/ch6/closures.rs:125:5
[INFO] [stderr]     |
[INFO] [stderr] 125 |     struct Closure {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `call_it`
[INFO] [stderr]    --> src/ch6/closures.rs:147:5
[INFO] [stderr]     |
[INFO] [stderr] 147 |     fn call_it<F: Fn() -> u32>(f: &F) -> u32 {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `call_it_mut`
[INFO] [stderr]    --> src/ch6/closures.rs:150:5
[INFO] [stderr]     |
[INFO] [stderr] 150 |     fn call_it_mut<F: FnMut() -> u32>(f: &mut F) -> u32 {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `call_it_once`
[INFO] [stderr]    --> src/ch6/closures.rs:153:5
[INFO] [stderr]     |
[INFO] [stderr] 153 |     fn call_it_once<F: FnOnce() -> u32>(f: F) -> u32 {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]    --> src/ch6/closures.rs:156:5
[INFO] [stderr]     |
[INFO] [stderr] 156 |     fn main() {
[INFO] [stderr]     |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]    --> src/ch6/closures.rs:352:5
[INFO] [stderr]     |
[INFO] [stderr] 352 |     fn main() {
[INFO] [stderr]     |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `boxed_closure`
[INFO] [stderr]    --> src/ch6/closures.rs:512:5
[INFO] [stderr]     |
[INFO] [stderr] 512 |     fn boxed_closure(c: &mut Vec<Box<Fn()>>){
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]    --> src/ch6/closures.rs:518:5
[INFO] [stderr]     |
[INFO] [stderr] 518 |     fn main(){
[INFO] [stderr]     |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `bar`
[INFO] [stderr]    --> src/ch6/closures.rs:638:5
[INFO] [stderr]     |
[INFO] [stderr] 638 |     fn bar(b: Box<for<'f> DoSomething<&'f usize>>) {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]    --> src/ch6/closures.rs:642:5
[INFO] [stderr]     |
[INFO] [stderr] 642 |     fn main(){
[INFO] [stderr]     |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]    --> src/ch6/iters.rs:373:5
[INFO] [stderr]     |
[INFO] [stderr] 373 |     fn main(){
[INFO] [stderr]     |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]   --> src/ch7/structs.rs:48:5
[INFO] [stderr]    |
[INFO] [stderr] 48 |     fn main(){
[INFO] [stderr]    |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `hello`
[INFO] [stderr]   --> src/appendix/mod.rs:16:1
[INFO] [stderr]    |
[INFO] [stderr] 16 | fn hello(){
[INFO] [stderr]    | ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]    --> src/appendix/lldb.rs:147:1
[INFO] [stderr]     |
[INFO] [stderr] 147 | fn main()
[INFO] [stderr]     | ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: denote infinite loops with `loop { ... }`
[INFO] [stderr]    --> src/ch2/control_flow.rs:152:5
[INFO] [stderr]     |
[INFO] [stderr] 152 |     while true {
[INFO] [stderr]     |     ^^^^^^^^^^ help: use `loop`
[INFO] [stderr]     |
[INFO] [stderr]     = note: #[warn(while_true)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused arithmetic operation that must be used
[INFO] [stderr]    --> src/ch5/nll.rs:184:9
[INFO] [stderr]     |
[INFO] [stderr] 184 |         a.to_string() + s;
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: #[warn(unused_must_use)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused attribute
[INFO] [stderr]    --> src/ch6/closures.rs:124:5
[INFO] [stderr]     |
[INFO] [stderr] 124 |     #![feature(unboxed_closures, fn_traits)]
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: #[warn(unused_attributes)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: crate-level attribute should be in the root module
[INFO] [stderr]    --> src/ch6/closures.rs:124:5
[INFO] [stderr]     |
[INFO] [stderr] 124 |     #![feature(unboxed_closures, fn_traits)]
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `sum`
[INFO] [stderr]   --> src/ch2/function.rs:89:1
[INFO] [stderr]    |
[INFO] [stderr] 89 | fn sum(a: i32, b: i32) -> i32 {
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(dead_code)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `product`
[INFO] [stderr]   --> src/ch2/function.rs:92:1
[INFO] [stderr]    |
[INFO] [stderr] 92 | fn product(a: i32, b: i32) -> i32 {
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `map_demo`
[INFO] [stderr]    --> src/ch2/collections.rs:169:1
[INFO] [stderr]     |
[INFO] [stderr] 169 | fn map_demo() {
[INFO] [stderr]     | ^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `foo`
[INFO] [stderr]    --> src/ch2/primitives.rs:349:1
[INFO] [stderr]     |
[INFO] [stderr] 349 | fn foo() -> u32 {
[INFO] [stderr]     | ^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `new`
[INFO] [stderr]   --> src/ch2/structs.rs:48:5
[INFO] [stderr]    |
[INFO] [stderr] 48 |     fn new(name: &'static str, gender: u32) -> Self{
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `name`
[INFO] [stderr]   --> src/ch2/structs.rs:51:5
[INFO] [stderr]    |
[INFO] [stderr] 51 |     fn name(&self) {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `set_name`
[INFO] [stderr]   --> src/ch2/structs.rs:54:5
[INFO] [stderr]    |
[INFO] [stderr] 54 |     fn set_name(&mut self, name: &'static str)  {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `gender`
[INFO] [stderr]   --> src/ch2/structs.rs:57:5
[INFO] [stderr]    |
[INFO] [stderr] 57 |     fn gender(&self){
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: field is never used: `foo`
[INFO] [stderr]   --> src/ch3/zero_size.rs:27:9
[INFO] [stderr]    |
[INFO] [stderr] 27 |         foo: Foo,
[INFO] [stderr]    |         ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: field is never used: `qux`
[INFO] [stderr]   --> src/ch3/zero_size.rs:28:9
[INFO] [stderr]    |
[INFO] [stderr] 28 |         qux: (),
[INFO] [stderr]    |         ^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: field is never used: `baz`
[INFO] [stderr]   --> src/ch3/zero_size.rs:29:9
[INFO] [stderr]    |
[INFO] [stderr] 29 |         baz: [u8; 0],
[INFO] [stderr]    |         ^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: field is never used: `page`
[INFO] [stderr]    --> src/ch3/traits.rs:262:24
[INFO] [stderr]     |
[INFO] [stderr] 262 |     struct MyPaginate{ page: i32 }
[INFO] [stderr]     |                        ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: field is never used: `inner`
[INFO] [stderr]    --> src/ch3/trait_limit.rs:147:9
[INFO] [stderr]     |
[INFO] [stderr] 147 |         inner: T,
[INFO] [stderr]     |         ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `foo`
[INFO] [stderr]   --> src/ch4/general_concepts.rs:17:5
[INFO] [stderr]    |
[INFO] [stderr] 17 |     fn foo(x: u32) {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]   --> src/ch4/general_concepts.rs:21:5
[INFO] [stderr]    |
[INFO] [stderr] 21 |     fn main(){
[INFO] [stderr]    |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `A`
[INFO] [stderr]   --> src/ch4/general_concepts.rs:56:5
[INFO] [stderr]    |
[INFO] [stderr] 56 |     struct A {
[INFO] [stderr]    |     ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]   --> src/ch4/general_concepts.rs:61:5
[INFO] [stderr]    |
[INFO] [stderr] 61 |     fn main() {
[INFO] [stderr]    |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `A`
[INFO] [stderr]   --> src/ch4/general_concepts.rs:96:5
[INFO] [stderr]    |
[INFO] [stderr] 96 |     struct A {
[INFO] [stderr]    |     ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `B`
[INFO] [stderr]    --> src/ch4/general_concepts.rs:100:5
[INFO] [stderr]     |
[INFO] [stderr] 100 |     struct B(i32, f64, char);
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `N`
[INFO] [stderr]    --> src/ch4/general_concepts.rs:101:5
[INFO] [stderr]     |
[INFO] [stderr] 101 |     struct N;
[INFO] [stderr]     |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: enum is never used: `E`
[INFO] [stderr]    --> src/ch4/general_concepts.rs:102:5
[INFO] [stderr]     |
[INFO] [stderr] 102 |     enum E {
[INFO] [stderr]     |     ^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: union is never used: `U`
[INFO] [stderr]    --> src/ch4/general_concepts.rs:106:5
[INFO] [stderr]     |
[INFO] [stderr] 106 |     union U {
[INFO] [stderr]     |     ^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]    --> src/ch4/general_concepts.rs:110:5
[INFO] [stderr]     |
[INFO] [stderr] 110 |     fn main(){
[INFO] [stderr]     |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]   --> src/ch4/resource_management.rs:59:5
[INFO] [stderr]    |
[INFO] [stderr] 59 |     fn main() {
[INFO] [stderr]    |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]   --> src/ch4/raii.rs:13:5
[INFO] [stderr]    |
[INFO] [stderr] 13 |     fn main() {
[INFO] [stderr]    |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `S`
[INFO] [stderr]   --> src/ch4/raii.rs:94:5
[INFO] [stderr]    |
[INFO] [stderr] 94 |     struct S(i32);
[INFO] [stderr]    |     ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]    --> src/ch4/raii.rs:100:5
[INFO] [stderr]     |
[INFO] [stderr] 100 |     fn main() {
[INFO] [stderr]     |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]   --> src/ch5/semantic.rs:27:5
[INFO] [stderr]    |
[INFO] [stderr] 27 |     fn main() {
[INFO] [stderr]    |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]    --> src/ch5/semantic.rs:111:5
[INFO] [stderr]     |
[INFO] [stderr] 111 |     fn main(){
[INFO] [stderr]     |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]   --> src/ch5/share_mutable.rs:21:5
[INFO] [stderr]    |
[INFO] [stderr] 21 |     fn main() {
[INFO] [stderr]    |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]    --> src/ch5/share_mutable.rs:132:5
[INFO] [stderr]     |
[INFO] [stderr] 132 |     fn main(){
[INFO] [stderr]     |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `foo`
[INFO] [stderr]   --> src/ch5/borrow.rs:31:5
[INFO] [stderr]    |
[INFO] [stderr] 31 |     fn foo(mut v: [i32; 3]) -> [i32; 3] {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]   --> src/ch5/borrow.rs:36:5
[INFO] [stderr]    |
[INFO] [stderr] 36 |     fn main() {
[INFO] [stderr]    |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `bubble_sort`
[INFO] [stderr]   --> src/ch5/borrow.rs:73:5
[INFO] [stderr]    |
[INFO] [stderr] 73 |     fn bubble_sort(a: &mut Vec<i32>) {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]   --> src/ch5/borrow.rs:90:5
[INFO] [stderr]    |
[INFO] [stderr] 90 |     fn main() {
[INFO] [stderr]    |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `compute`
[INFO] [stderr]    --> src/ch5/borrow.rs:139:5
[INFO] [stderr]     |
[INFO] [stderr] 139 |     fn compute(input: &u32, output: &mut u32) {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]    --> src/ch5/borrow.rs:147:5
[INFO] [stderr]     |
[INFO] [stderr] 147 |     fn main() {
[INFO] [stderr]     |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]   --> src/ch5/lifetime.rs:16:5
[INFO] [stderr]    |
[INFO] [stderr] 16 |     fn main() {
[INFO] [stderr]    |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]    --> src/ch5/lifetime.rs:239:5
[INFO] [stderr]     |
[INFO] [stderr] 239 |     fn main() {
[INFO] [stderr]     |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `foo`
[INFO] [stderr]    --> src/ch5/nll.rs:117:5
[INFO] [stderr]     |
[INFO] [stderr] 117 |     fn foo<'a>(x: &'a str, y: &'a str) -> &'a str {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]    --> src/ch5/nll.rs:124:5
[INFO] [stderr]     |
[INFO] [stderr] 124 |     fn main(){
[INFO] [stderr]     |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]    --> src/ch5/nll.rs:181:5
[INFO] [stderr]     |
[INFO] [stderr] 181 |     fn main(){
[INFO] [stderr]     |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `modify`
[INFO] [stderr]   --> src/ch6/functions.rs:30:5
[INFO] [stderr]    |
[INFO] [stderr] 30 |     fn modify(mut v: Vec<u32>) -> Vec<u32> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]   --> src/ch6/functions.rs:34:5
[INFO] [stderr]    |
[INFO] [stderr] 34 |     fn main(){
[INFO] [stderr]    |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `f`
[INFO] [stderr]   --> src/ch6/functions.rs:71:5
[INFO] [stderr]    |
[INFO] [stderr] 71 |     fn f() { print!("1"); }
[INFO] [stderr]    |     ^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]   --> src/ch6/functions.rs:72:5
[INFO] [stderr]    |
[INFO] [stderr] 72 |     fn main() {
[INFO] [stderr]    |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `S`
[INFO] [stderr]    --> src/ch6/functions.rs:126:5
[INFO] [stderr]     |
[INFO] [stderr] 126 |     struct S { i: i32 }
[INFO] [stderr]     |     ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `f`
[INFO] [stderr]    --> src/ch6/functions.rs:127:5
[INFO] [stderr]     |
[INFO] [stderr] 127 |     fn f(ref _s: S) {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]    --> src/ch6/functions.rs:130:5
[INFO] [stderr]     |
[INFO] [stderr] 130 |     fn main() {
[INFO] [stderr]     |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `addsub`
[INFO] [stderr]    --> src/ch6/functions.rs:167:5
[INFO] [stderr]     |
[INFO] [stderr] 167 |     fn addsub(x: isize, y: isize) -> (isize, isize) {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]    --> src/ch6/functions.rs:170:5
[INFO] [stderr]     |
[INFO] [stderr] 170 |     fn main(){
[INFO] [stderr]     |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `square`
[INFO] [stderr]    --> src/ch6/functions.rs:210:5
[INFO] [stderr]     |
[INFO] [stderr] 210 |     fn square<T: Mul<T, Output=T>>(x: T, y: T) -> T {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]    --> src/ch6/functions.rs:213:5
[INFO] [stderr]     |
[INFO] [stderr] 213 |     fn main() {
[INFO] [stderr]     |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `User`
[INFO] [stderr]    --> src/ch6/functions.rs:249:5
[INFO] [stderr]     |
[INFO] [stderr] 249 |     struct User {
[INFO] [stderr]     |     ^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `show`
[INFO] [stderr]    --> src/ch6/functions.rs:254:9
[INFO] [stderr]     |
[INFO] [stderr] 254 |         fn show(&self)  {
[INFO] [stderr]     |         ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]    --> src/ch6/functions.rs:259:5
[INFO] [stderr]     |
[INFO] [stderr] 259 |     fn main() {
[INFO] [stderr]     |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `math`
[INFO] [stderr]    --> src/ch6/functions.rs:399:5
[INFO] [stderr]     |
[INFO] [stderr] 399 |     fn math(op: fn(i32, i32) -> i32, a: i32, b: i32) -> i32{
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `sum`
[INFO] [stderr]    --> src/ch6/functions.rs:402:5
[INFO] [stderr]     |
[INFO] [stderr] 402 |     fn sum(a: i32, b: i32) -> i32 {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `product`
[INFO] [stderr]    --> src/ch6/functions.rs:405:5
[INFO] [stderr]     |
[INFO] [stderr] 405 |     fn product(a: i32, b: i32) -> i32 {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]    --> src/ch6/functions.rs:408:5
[INFO] [stderr]     |
[INFO] [stderr] 408 |     fn main() {
[INFO] [stderr]     |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `counter`
[INFO] [stderr]   --> src/ch6/closures.rs:48:5
[INFO] [stderr]    |
[INFO] [stderr] 48 |     fn counter(i: i32) -> Box<Fn(i32) -> i32> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]   --> src/ch6/closures.rs:51:5
[INFO] [stderr]    |
[INFO] [stderr] 51 |     fn main() {
[INFO] [stderr]    |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `Closure`
[INFO] [stderr]    --> src/ch6/closures.rs:125:5
[INFO] [stderr]     |
[INFO] [stderr] 125 |     struct Closure {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `call_it`
[INFO] [stderr]    --> src/ch6/closures.rs:147:5
[INFO] [stderr]     |
[INFO] [stderr] 147 |     fn call_it<F: Fn() -> u32>(f: &F) -> u32 {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `call_it_mut`
[INFO] [stderr]    --> src/ch6/closures.rs:150:5
[INFO] [stderr]     |
[INFO] [stderr] 150 |     fn call_it_mut<F: FnMut() -> u32>(f: &mut F) -> u32 {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `call_it_once`
[INFO] [stderr]    --> src/ch6/closures.rs:153:5
[INFO] [stderr]     |
[INFO] [stderr] 153 |     fn call_it_once<F: FnOnce() -> u32>(f: F) -> u32 {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]    --> src/ch6/closures.rs:156:5
[INFO] [stderr]     |
[INFO] [stderr] 156 |     fn main() {
[INFO] [stderr]     |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]    --> src/ch6/closures.rs:352:5
[INFO] [stderr]     |
[INFO] [stderr] 352 |     fn main() {
[INFO] [stderr]     |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `boxed_closure`
[INFO] [stderr]    --> src/ch6/closures.rs:512:5
[INFO] [stderr]     |
[INFO] [stderr] 512 |     fn boxed_closure(c: &mut Vec<Box<Fn()>>){
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]    --> src/ch6/closures.rs:518:5
[INFO] [stderr]     |
[INFO] [stderr] 518 |     fn main(){
[INFO] [stderr]     |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `bar`
[INFO] [stderr]    --> src/ch6/closures.rs:638:5
[INFO] [stderr]     |
[INFO] [stderr] 638 |     fn bar(b: Box<for<'f> DoSomething<&'f usize>>) {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]    --> src/ch6/closures.rs:642:5
[INFO] [stderr]     |
[INFO] [stderr] 642 |     fn main(){
[INFO] [stderr]     |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]    --> src/ch6/iters.rs:373:5
[INFO] [stderr]     |
[INFO] [stderr] 373 |     fn main(){
[INFO] [stderr]     |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]   --> src/ch7/structs.rs:48:5
[INFO] [stderr]    |
[INFO] [stderr] 48 |     fn main(){
[INFO] [stderr]    |     ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `hello`
[INFO] [stderr]   --> src/appendix/mod.rs:16:1
[INFO] [stderr]    |
[INFO] [stderr] 16 | fn hello(){
[INFO] [stderr]    | ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function is never used: `main`
[INFO] [stderr]    --> src/appendix/lldb.rs:147:1
[INFO] [stderr]     |
[INFO] [stderr] 147 | fn main()
[INFO] [stderr]     | ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: denote infinite loops with `loop { ... }`
[INFO] [stderr]    --> src/ch2/control_flow.rs:152:5
[INFO] [stderr]     |
[INFO] [stderr] 152 |     while true {
[INFO] [stderr]     |     ^^^^^^^^^^ help: use `loop`
[INFO] [stderr]     |
[INFO] [stderr]     = note: #[warn(while_true)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused arithmetic operation that must be used
[INFO] [stderr]    --> src/ch5/nll.rs:184:9
[INFO] [stderr]     |
[INFO] [stderr] 184 |         a.to_string() + s;
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: #[warn(unused_must_use)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused attribute
[INFO] [stderr]    --> src/ch6/closures.rs:124:5
[INFO] [stderr]     |
[INFO] [stderr] 124 |     #![feature(unboxed_closures, fn_traits)]
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: #[warn(unused_attributes)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: crate-level attribute should be in the root module
[INFO] [stderr]    --> src/ch6/closures.rs:124:5
[INFO] [stderr]     |
[INFO] [stderr] 124 |     #![feature(unboxed_closures, fn_traits)]
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 3.27s
[INFO] running `"docker" "inspect" "0b8d28f155c1134ff2221295f5f7c4e5c6a1817e806d9c741c5582f47acc9864"`
[INFO] running `"docker" "rm" "-f" "0b8d28f155c1134ff2221295f5f7c4e5c6a1817e806d9c741c5582f47acc9864"`
[INFO] [stdout] 0b8d28f155c1134ff2221295f5f7c4e5c6a1817e806d9c741c5582f47acc9864