[INFO] updating cached repository PeterCxy/huffman-coding-cse104-rust
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/PeterCxy/huffman-coding-cse104-rust
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/PeterCxy/huffman-coding-cse104-rust" "work/ex/clippy-test-run/sources/stable/gh/PeterCxy/huffman-coding-cse104-rust"`
[INFO] [stderr] Cloning into 'work/ex/clippy-test-run/sources/stable/gh/PeterCxy/huffman-coding-cse104-rust'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/PeterCxy/huffman-coding-cse104-rust" "work/ex/clippy-test-run/sources/stable+rustflags=-Dclippy%3A%3Ainto_iter_on_array/gh/PeterCxy/huffman-coding-cse104-rust"`
[INFO] [stderr] Cloning into 'work/ex/clippy-test-run/sources/stable+rustflags=-Dclippy%3A%3Ainto_iter_on_array/gh/PeterCxy/huffman-coding-cse104-rust'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] f8dae1c157f776aaa7c340f21ebca5741efc6893
[INFO] sha for GitHub repo PeterCxy/huffman-coding-cse104-rust: f8dae1c157f776aaa7c340f21ebca5741efc6893
[INFO] validating manifest of PeterCxy/huffman-coding-cse104-rust on toolchain stable
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+stable" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of PeterCxy/huffman-coding-cse104-rust on toolchain stable+rustflags=-Dclippy::into_iter_on_array
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+stable" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing PeterCxy/huffman-coding-cse104-rust
[INFO] finished frobbing PeterCxy/huffman-coding-cse104-rust
[INFO] frobbed toml for PeterCxy/huffman-coding-cse104-rust written to work/ex/clippy-test-run/sources/stable/gh/PeterCxy/huffman-coding-cse104-rust/Cargo.toml
[INFO] started frobbing PeterCxy/huffman-coding-cse104-rust
[INFO] finished frobbing PeterCxy/huffman-coding-cse104-rust
[INFO] frobbed toml for PeterCxy/huffman-coding-cse104-rust written to work/ex/clippy-test-run/sources/stable+rustflags=-Dclippy%3A%3Ainto_iter_on_array/gh/PeterCxy/huffman-coding-cse104-rust/Cargo.toml
[INFO] crate PeterCxy/huffman-coding-cse104-rust has a lockfile. skipping
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+stable" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+stable" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] linting PeterCxy/huffman-coding-cse104-rust against stable for clippy-test-run
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/clippy-test-run/worker-4/stable:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/clippy-test-run/sources/stable/gh/PeterCxy/huffman-coding-cse104-rust:/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" "+stable" "clippy" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] 6aaae92ef8bf9063345f205536ef0390b6ec048d3a809aee8b27134e3ec43c7c
[INFO] running `"docker" "start" "-a" "6aaae92ef8bf9063345f205536ef0390b6ec048d3a809aee8b27134e3ec43c7c"`
[INFO] [stderr]     Checking huffman v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/bitvec.rs:16:9
[INFO] [stderr]    |
[INFO] [stderr] 16 |         return n;
[INFO] [stderr]    |         ^^^^^^^^^ help: remove `return` as shown: `n`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(clippy::needless_return)] on by default
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/traversal.rs:96:9
[INFO] [stderr]    |
[INFO] [stderr] 96 |         return None;
[INFO] [stderr]    |         ^^^^^^^^^^^^ help: remove `return` as shown: `None`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/main.rs:22:5
[INFO] [stderr]    |
[INFO] [stderr] 22 |     return ret;
[INFO] [stderr]    |     ^^^^^^^^^^^ help: remove `return` as shown: `ret`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/main.rs:42:5
[INFO] [stderr]    |
[INFO] [stderr] 42 |     return freq_table;
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `freq_table`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/main.rs:53:5
[INFO] [stderr]    |
[INFO] [stderr] 53 |     return ret;
[INFO] [stderr]    |     ^^^^^^^^^^^ help: remove `return` as shown: `ret`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/main.rs:66:5
[INFO] [stderr]    |
[INFO] [stderr] 66 |     return ret;
[INFO] [stderr]    |     ^^^^^^^^^^^ help: remove `return` as shown: `ret`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/main.rs:98:5
[INFO] [stderr]     |
[INFO] [stderr] 98  | /     return TreeNode::Root(Root {
[INFO] [stderr] 99  | |         left: Box::new(vec.remove(0)),
[INFO] [stderr] 100 | |         right: Box::new(vec.remove(0))
[INFO] [stderr] 101 | |     });
[INFO] [stderr]     | |_______^
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] help: remove `return` as shown
[INFO] [stderr]     |
[INFO] [stderr] 98  |     TreeNode::Root(Root {
[INFO] [stderr] 99  |         left: Box::new(vec.remove(0)),
[INFO] [stderr] 100 |         right: Box::new(vec.remove(0))
[INFO] [stderr] 101 |     })
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/main.rs:112:5
[INFO] [stderr]     |
[INFO] [stderr] 112 |     return ret;
[INFO] [stderr]     |     ^^^^^^^^^^^ help: remove `return` as shown: `ret`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/main.rs:138:5
[INFO] [stderr]     |
[INFO] [stderr] 138 |     return (freq_table, ret.to_bytes(), 8 - (ret.len() % 8) as u8);
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `(freq_table, ret.to_bytes(), 8 - (ret.len() % 8) as u8)`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/main.rs:174:5
[INFO] [stderr]     |
[INFO] [stderr] 174 |     return ret;
[INFO] [stderr]     |     ^^^^^^^^^^^ help: remove `return` as shown: `ret`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/main.rs:204:5
[INFO] [stderr]     |
[INFO] [stderr] 204 |     return ret;
[INFO] [stderr]     |     ^^^^^^^^^^^ help: remove `return` as shown: `ret`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/main.rs:281:5
[INFO] [stderr]     |
[INFO] [stderr] 281 |     return ret;
[INFO] [stderr]     |     ^^^^^^^^^^^ help: remove `return` as shown: `ret`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: length comparison to zero
[INFO] [stderr]   --> src/traversal.rs:84:15
[INFO] [stderr]    |
[INFO] [stderr] 84 |         while self.traversers.len() > 0 {
[INFO] [stderr]    |               ^^^^^^^^^^^^^^^^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `!self.traversers.is_empty()`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(clippy::len_zero)] on by default
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#len_zero
[INFO] [stderr] 
[INFO] [stderr] warning: slow zero-filling initialization
[INFO] [stderr]   --> src/main.rs:27:5
[INFO] [stderr]    |
[INFO] [stderr] 26 |     let mut v = Vec::with_capacity(4);
[INFO] [stderr]    |                 --------------------- help: consider replace allocation with: `vec![0; 4]`
[INFO] [stderr] 27 |     v.resize(4, 0);
[INFO] [stderr]    |     ^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(clippy::slow_vector_initialization)] on by default
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#slow_vector_initialization
[INFO] [stderr] 
[INFO] [stderr] warning: You are using an explicit closure for cloning elements
[INFO] [stderr]   --> src/main.rs:39:17
[INFO] [stderr]    |
[INFO] [stderr] 39 |         let n = freq_table.get(i).map(|x| x.clone()).unwrap_or(0);
[INFO] [stderr]    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: Consider calling the dedicated `cloned` method: `freq_table.get(i).cloned()`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(clippy::map_clone)] on by default
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#map_clone
[INFO] [stderr] 
[INFO] [stderr] warning: using `clone` on a `Copy` type
[INFO] [stderr]   --> src/main.rs:39:43
[INFO] [stderr]    |
[INFO] [stderr] 39 |         let n = freq_table.get(i).map(|x| x.clone()).unwrap_or(0);
[INFO] [stderr]    |                                           ^^^^^^^^^ help: try dereferencing it: `*x`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(clippy::clone_on_copy)] on by default
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#clone_on_copy
[INFO] [stderr] 
[INFO] [stderr] warning: called `.get().unwrap()` on a HashMap. Using `[]` is more clear and more concise
[INFO] [stderr]    --> src/main.rs:135:24
[INFO] [stderr]     |
[INFO] [stderr] 135 |         ret.append_all(dict.get(item).unwrap().clone());
[INFO] [stderr]     |                        ^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `&dict[item]`
[INFO] [stderr]     |
[INFO] [stderr]     = note: #[warn(clippy::get_unwrap)] on by default
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#get_unwrap
[INFO] [stderr] 
[INFO] [stderr] warning: length comparison to zero
[INFO] [stderr]    --> src/main.rs:264:8
[INFO] [stderr]     |
[INFO] [stderr] 264 |     if data.len() == 0 {
[INFO] [stderr]     |        ^^^^^^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `data.is_empty()`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#len_zero
[INFO] [stderr] 
[INFO] [stderr] error: handle written amount returned or use `Write::write_all` instead
[INFO] [stderr]    --> src/main.rs:285:5
[INFO] [stderr]     |
[INFO] [stderr] 285 |     File::create(file).unwrap().write(data).unwrap();
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: #[deny(clippy::unused_io_amount)] on by default
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unused_io_amount
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/bitvec.rs:16:9
[INFO] [stderr]    |
[INFO] [stderr] 16 |         return n;
[INFO] [stderr]    |         ^^^^^^^^^ help: remove `return` as shown: `n`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(clippy::needless_return)] on by default
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/traversal.rs:96:9
[INFO] [stderr]    |
[INFO] [stderr] 96 |         return None;
[INFO] [stderr]    |         ^^^^^^^^^^^^ help: remove `return` as shown: `None`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/main.rs:22:5
[INFO] [stderr]    |
[INFO] [stderr] 22 |     return ret;
[INFO] [stderr]    |     ^^^^^^^^^^^ help: remove `return` as shown: `ret`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/main.rs:42:5
[INFO] [stderr]    |
[INFO] [stderr] 42 |     return freq_table;
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `freq_table`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/main.rs:53:5
[INFO] [stderr]    |
[INFO] [stderr] 53 |     return ret;
[INFO] [stderr]    |     ^^^^^^^^^^^ help: remove `return` as shown: `ret`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/main.rs:66:5
[INFO] [stderr]    |
[INFO] [stderr] 66 |     return ret;
[INFO] [stderr]    |     ^^^^^^^^^^^ help: remove `return` as shown: `ret`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/main.rs:98:5
[INFO] [stderr]     |
[INFO] [stderr] 98  | /     return TreeNode::Root(Root {
[INFO] [stderr] 99  | |         left: Box::new(vec.remove(0)),
[INFO] [stderr] 100 | |         right: Box::new(vec.remove(0))
[INFO] [stderr] 101 | |     });
[INFO] [stderr]     | |_______^
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] help: remove `return` as shown
[INFO] [stderr]     |
[INFO] [stderr] 98  |     TreeNode::Root(Root {
[INFO] [stderr] 99  |         left: Box::new(vec.remove(0)),
[INFO] [stderr] 100 |         right: Box::new(vec.remove(0))
[INFO] [stderr] 101 |     })
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/main.rs:112:5
[INFO] [stderr]     |
[INFO] [stderr] 112 |     return ret;
[INFO] [stderr]     |     ^^^^^^^^^^^ help: remove `return` as shown: `ret`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/main.rs:138:5
[INFO] [stderr]     |
[INFO] [stderr] 138 |     return (freq_table, ret.to_bytes(), 8 - (ret.len() % 8) as u8);
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `(freq_table, ret.to_bytes(), 8 - (ret.len() % 8) as u8)`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/main.rs:174:5
[INFO] [stderr]     |
[INFO] [stderr] 174 |     return ret;
[INFO] [stderr]     |     ^^^^^^^^^^^ help: remove `return` as shown: `ret`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/main.rs:204:5
[INFO] [stderr]     |
[INFO] [stderr] 204 |     return ret;
[INFO] [stderr]     |     ^^^^^^^^^^^ help: remove `return` as shown: `ret`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/main.rs:281:5
[INFO] [stderr]     |
[INFO] [stderr] 281 |     return ret;
[INFO] [stderr]     |     ^^^^^^^^^^^ help: remove `return` as shown: `ret`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] error: Could not compile `huffman`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] warning: length comparison to zero
[INFO] [stderr]   --> src/traversal.rs:84:15
[INFO] [stderr]    |
[INFO] [stderr] 84 |         while self.traversers.len() > 0 {
[INFO] [stderr]    |               ^^^^^^^^^^^^^^^^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `!self.traversers.is_empty()`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(clippy::len_zero)] on by default
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#len_zero
[INFO] [stderr] 
[INFO] [stderr] warning: slow zero-filling initialization
[INFO] [stderr]   --> src/main.rs:27:5
[INFO] [stderr]    |
[INFO] [stderr] 26 |     let mut v = Vec::with_capacity(4);
[INFO] [stderr]    |                 --------------------- help: consider replace allocation with: `vec![0; 4]`
[INFO] [stderr] 27 |     v.resize(4, 0);
[INFO] [stderr]    |     ^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(clippy::slow_vector_initialization)] on by default
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#slow_vector_initialization
[INFO] [stderr] 
[INFO] [stderr] warning: You are using an explicit closure for cloning elements
[INFO] [stderr]   --> src/main.rs:39:17
[INFO] [stderr]    |
[INFO] [stderr] 39 |         let n = freq_table.get(i).map(|x| x.clone()).unwrap_or(0);
[INFO] [stderr]    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: Consider calling the dedicated `cloned` method: `freq_table.get(i).cloned()`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(clippy::map_clone)] on by default
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#map_clone
[INFO] [stderr] 
[INFO] [stderr] warning: using `clone` on a `Copy` type
[INFO] [stderr]   --> src/main.rs:39:43
[INFO] [stderr]    |
[INFO] [stderr] 39 |         let n = freq_table.get(i).map(|x| x.clone()).unwrap_or(0);
[INFO] [stderr]    |                                           ^^^^^^^^^ help: try dereferencing it: `*x`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(clippy::clone_on_copy)] on by default
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#clone_on_copy
[INFO] [stderr] 
[INFO] [stderr] warning: called `.get().unwrap()` on a HashMap. Using `[]` is more clear and more concise
[INFO] [stderr]    --> src/main.rs:135:24
[INFO] [stderr]     |
[INFO] [stderr] 135 |         ret.append_all(dict.get(item).unwrap().clone());
[INFO] [stderr]     |                        ^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `&dict[item]`
[INFO] [stderr]     |
[INFO] [stderr]     = note: #[warn(clippy::get_unwrap)] on by default
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#get_unwrap
[INFO] [stderr] 
[INFO] [stderr] warning: length comparison to zero
[INFO] [stderr]    --> src/main.rs:264:8
[INFO] [stderr]     |
[INFO] [stderr] 264 |     if data.len() == 0 {
[INFO] [stderr]     |        ^^^^^^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `data.is_empty()`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#len_zero
[INFO] [stderr] 
[INFO] [stderr] error: handle written amount returned or use `Write::write_all` instead
[INFO] [stderr]    --> src/main.rs:285:5
[INFO] [stderr]     |
[INFO] [stderr] 285 |     File::create(file).unwrap().write(data).unwrap();
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: #[deny(clippy::unused_io_amount)] on by default
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unused_io_amount
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] error: Could not compile `huffman`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "6aaae92ef8bf9063345f205536ef0390b6ec048d3a809aee8b27134e3ec43c7c"`
[INFO] running `"docker" "rm" "-f" "6aaae92ef8bf9063345f205536ef0390b6ec048d3a809aee8b27134e3ec43c7c"`
[INFO] [stdout] 6aaae92ef8bf9063345f205536ef0390b6ec048d3a809aee8b27134e3ec43c7c