[INFO] cloning repository https://github.com/stryukovsky/rust-excercises
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/stryukovsky/rust-excercises" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fstryukovsky%2Frust-excercises", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fstryukovsky%2Frust-excercises'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 251cbe26eb6bf8e39ee80519d15158b1ddd22441
[INFO] testing stryukovsky/rust-excercises against master#c90bcb9571b7aab0d8beaa2ce8a998ffaf079d38 for pr-146098-7
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fstryukovsky%2Frust-excercises" "/workspace/builds/worker-0-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc1/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/stryukovsky/rust-excercises
[INFO] finished tweaking git repo https://github.com/stryukovsky/rust-excercises
[INFO] tweaked toml for git repo https://github.com/stryukovsky/rust-excercises written to /workspace/builds/worker-0-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/stryukovsky/rust-excercises on toolchain c90bcb9571b7aab0d8beaa2ce8a998ffaf079d38
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+c90bcb9571b7aab0d8beaa2ce8a998ffaf079d38" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/stryukovsky/rust-excercises 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" "+c90bcb9571b7aab0d8beaa2ce8a998ffaf079d38" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+c90bcb9571b7aab0d8beaa2ce8a998ffaf079d38" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] bb789e3899dbc5c201f877bffbb792a9eaa8ea1b187a1a6d3e3e14af72b3d538
[INFO] running `Command { std: "docker" "start" "-a" "bb789e3899dbc5c201f877bffbb792a9eaa8ea1b187a1a6d3e3e14af72b3d538", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "bb789e3899dbc5c201f877bffbb792a9eaa8ea1b187a1a6d3e3e14af72b3d538", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "bb789e3899dbc5c201f877bffbb792a9eaa8ea1b187a1a6d3e3e14af72b3d538", kill_on_drop: false }`
[INFO] [stdout] bb789e3899dbc5c201f877bffbb792a9eaa8ea1b187a1a6d3e3e14af72b3d538
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+c90bcb9571b7aab0d8beaa2ce8a998ffaf079d38" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] e60e673849175780271eeab3b270116a1609ede7ff6459c2e1c09a7e06d3c2f3
[INFO] running `Command { std: "docker" "start" "-a" "e60e673849175780271eeab3b270116a1609ede7ff6459c2e1c09a7e06d3c2f3", kill_on_drop: false }`
[INFO] [stderr]    Compiling rust-excercises v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `borrow::Borrow`
[INFO] [stdout]  --> src/structures/dequeue.rs:1:48
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::{cell::RefCell, fmt::Display, rc::Rc, borrow::Borrow};
[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: `vec`
[INFO] [stdout]  --> src/structures/bytes_storage.rs:1:25
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::{fmt::Display, vec};
[INFO] [stdout]   |                         ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: irrefutable `if let` pattern
[INFO] [stdout]   --> src/algorithms/binary_tree_inorder_traversal.rs:24:12
[INFO] [stdout]    |
[INFO] [stdout] 24 |         if let node = node.try_borrow().ok() {
[INFO] [stdout]    |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this pattern will always match, so the `if let` is useless
[INFO] [stdout]    = help: consider replacing the `if let` with a `let`
[INFO] [stdout]    = note: `#[warn(irrefutable_let_patterns)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `previous_result`
[INFO] [stdout]  --> src/algorithms/reverse_array.rs:8:9
[INFO] [stdout]   |
[INFO] [stdout] 8 |     let previous_result = replace(array, reversed);
[INFO] [stdout]   |         ^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_previous_result`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `TreeNode` is never constructed
[INFO] [stdout]  --> src/algorithms/binary_tree_inorder_traversal.rs:2:12
[INFO] [stdout]   |
[INFO] [stdout] 2 | pub struct TreeNode {
[INFO] [stdout]   |            ^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]   --> src/algorithms/binary_tree_inorder_traversal.rs:10:12
[INFO] [stdout]    |
[INFO] [stdout]  8 | impl TreeNode {
[INFO] [stdout]    | ------------- associated function in this implementation
[INFO] [stdout]  9 |     #[inline]
[INFO] [stdout] 10 |     pub fn new(val: i32) -> Self {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `inorder_traversal` is never used
[INFO] [stdout]   --> src/algorithms/binary_tree_inorder_traversal.rs:34:8
[INFO] [stdout]    |
[INFO] [stdout] 34 | pub fn inorder_traversal(root: Option<Rc<RefCell<TreeNode>>>) -> Vec<i32> {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `sorted_array_to_bst` is never used
[INFO] [stdout]  --> src/algorithms/convert_sorted_array_to_binary_search_tree.rs:8:8
[INFO] [stdout]   |
[INFO] [stdout] 8 | pub fn sorted_array_to_bst(nums: Vec<i32>) -> Option<Rc<RefCell<TreeNode>>> {
[INFO] [stdout]   |        ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `find_the_difference` is never used
[INFO] [stdout]  --> src/algorithms/find_the_difference.rs:1:8
[INFO] [stdout]   |
[INFO] [stdout] 1 | pub fn find_the_difference(s: String, t: String) -> char {
[INFO] [stdout]   |        ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `is_word_meets_criteria` is never used
[INFO] [stdout]  --> src/algorithms/find_words_that_can_be_formed_by_characters.rs:3:4
[INFO] [stdout]   |
[INFO] [stdout] 3 | fn is_word_meets_criteria(word: &String, mut criteria: HashMap<char, u8>) -> bool {
[INFO] [stdout]   |    ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `count_characters` is never used
[INFO] [stdout]   --> src/algorithms/find_words_that_can_be_formed_by_characters.rs:17:8
[INFO] [stdout]    |
[INFO] [stdout] 17 | pub fn count_characters(words: Vec<String>, chars: String) -> i32 {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `first_uniq_char` is never used
[INFO] [stdout]  --> src/algorithms/first_unique_character_in_a_string.rs:3:8
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub fn first_uniq_char(s: String) -> i32 {
[INFO] [stdout]   |        ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `get_squared_sum` is never used
[INFO] [stdout]  --> src/algorithms/is_happy.rs:3:8
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub fn get_squared_sum(number: i32) -> i32 {
[INFO] [stdout]   |        ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `is_happy` is never used
[INFO] [stdout]   --> src/algorithms/is_happy.rs:13:8
[INFO] [stdout]    |
[INFO] [stdout] 13 | pub fn is_happy(n: i32) -> bool {
[INFO] [stdout]    |        ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `longest_common_prefix` is never used
[INFO] [stdout]  --> src/algorithms/longest_common_prefix.rs:3:8
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub fn longest_common_prefix(strs: Vec<String>) -> String {
[INFO] [stdout]   |        ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `majority_element` is never used
[INFO] [stdout]  --> src/algorithms/majority_element.rs:3:8
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub fn majority_element(nums: Vec<i32>) -> i32 {
[INFO] [stdout]   |        ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `ListNode` is never constructed
[INFO] [stdout]  --> src/algorithms/palindrome_linked_list.rs:2:12
[INFO] [stdout]   |
[INFO] [stdout] 2 | pub struct ListNode {
[INFO] [stdout]   |            ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]  --> src/algorithms/palindrome_linked_list.rs:9:8
[INFO] [stdout]   |
[INFO] [stdout] 7 | impl ListNode {
[INFO] [stdout]   | ------------- associated function in this implementation
[INFO] [stdout] 8 |     #[inline]
[INFO] [stdout] 9 |     fn new(val: i32) -> Self {
[INFO] [stdout]   |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `is_palindrome` is never used
[INFO] [stdout]   --> src/algorithms/palindrome_linked_list.rs:18:8
[INFO] [stdout]    |
[INFO] [stdout] 18 | pub fn is_palindrome(head: Option<Box<ListNode>>) -> bool {
[INFO] [stdout]    |        ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `build_reverse` is never used
[INFO] [stdout]   --> src/algorithms/palindrome_linked_list.rs:39:8
[INFO] [stdout]    |
[INFO] [stdout] 39 | pub fn build_reverse(head: &mut Option<Box<ListNode>>) -> Option<Box<ListNode>> {
[INFO] [stdout]    |        ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `is_palindrome` is never used
[INFO] [stdout]  --> src/algorithms/palindrome_number.rs:1:8
[INFO] [stdout]   |
[INFO] [stdout] 1 | pub fn is_palindrome(x: i32) -> bool {
[INFO] [stdout]   |        ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `pascal_triangle` is never used
[INFO] [stdout]  --> src/algorithms/pascal_triangle.rs:1:8
[INFO] [stdout]   |
[INFO] [stdout] 1 | pub fn pascal_triangle(num_rows: u32) -> Vec<Vec<i32>> {
[INFO] [stdout]   |        ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `roman_to_int` is never used
[INFO] [stdout]  --> src/algorithms/roman_to_integer.rs:3:8
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub fn roman_to_int(s: String) -> i32 {
[INFO] [stdout]   |        ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `search_insert` is never used
[INFO] [stdout]   --> src/algorithms/search_insert_position.rs:29:8
[INFO] [stdout]    |
[INFO] [stdout] 29 | pub fn search_insert(nums: Vec<i32>, target: i32) -> i32 {
[INFO] [stdout]    |        ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `two_sum` is never used
[INFO] [stdout]  --> src/algorithms/two_sum.rs:1:8
[INFO] [stdout]   |
[INFO] [stdout] 1 | pub fn two_sum(nums: Vec<i32>, target: i32) -> Vec<i32> {
[INFO] [stdout]   |        ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `get_closing_parenthesis` is never used
[INFO] [stdout]  --> src/algorithms/valid_parentheses.rs:1:4
[INFO] [stdout]   |
[INFO] [stdout] 1 | fn get_closing_parenthesis(opening_parenthesis: &char) -> Option<char> {
[INFO] [stdout]   |    ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `is_valid` is never used
[INFO] [stdout]   --> src/algorithms/valid_parentheses.rs:10:8
[INFO] [stdout]    |
[INFO] [stdout] 10 | pub fn is_valid(s: String) -> bool {
[INFO] [stdout]    |        ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `first_earlier_than_second` is never used
[INFO] [stdout]  --> src/algorithms/verifying_an_alien_dictionary.rs:3:8
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub fn first_earlier_than_second(first: &String, second: &String, dictionary: &HashMap<char, usize>) -> bool {
[INFO] [stdout]   |        ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `is_alien_sorted` is never used
[INFO] [stdout]   --> src/algorithms/verifying_an_alien_dictionary.rs:26:8
[INFO] [stdout]    |
[INFO] [stdout] 26 | pub fn is_alien_sorted(words: Vec<String>, order: String) -> bool {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `reverse_array` is never used
[INFO] [stdout]  --> src/algorithms/reverse_array.rs:3:8
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub fn reverse_array<T: Default>(array: &mut Vec<T>) {
[INFO] [stdout]   |        ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Container` is never constructed
[INFO] [stdout]  --> src/structures/container.rs:3:12
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub struct Container<T: Eq + Hash + Clone> {
[INFO] [stdout]   |            ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated items `new`, `push`, `get`, `get_unique_items_count`, `get_size`, and `iter` are never used
[INFO] [stdout]   --> src/structures/container.rs:11:12
[INFO] [stdout]    |
[INFO] [stdout] 10 | impl <T: Eq + Hash + Clone> Container<T> {
[INFO] [stdout]    | ---------------------------------------- associated items in this implementation
[INFO] [stdout] 11 |     pub fn new() -> Self {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] ...
[INFO] [stdout] 20 |     pub fn push(&mut self, item: T) {
[INFO] [stdout]    |            ^^^^
[INFO] [stdout] ...
[INFO] [stdout] 32 |     pub fn get(&self, index: usize) -> Option<&T> {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] ...
[INFO] [stdout] 36 |     pub fn get_unique_items_count(&self) -> usize {
[INFO] [stdout]    |            ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 40 |     pub fn get_size(&self) -> usize {
[INFO] [stdout]    |            ^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 44 |     pub fn iter(&self) -> Iter<T> {
[INFO] [stdout]    |            ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `DequeueNode` is never constructed
[INFO] [stdout]  --> src/structures/dequeue.rs:3:12
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub struct DequeueNode<T> {
[INFO] [stdout]   |            ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]   --> src/structures/dequeue.rs:10:12
[INFO] [stdout]    |
[INFO] [stdout]  9 | impl<T> DequeueNode<T> {
[INFO] [stdout]    | ---------------------- associated function in this implementation
[INFO] [stdout] 10 |     pub fn new(data: T) -> Self {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Dequeue` is never constructed
[INFO] [stdout]   --> src/structures/dequeue.rs:19:12
[INFO] [stdout]    |
[INFO] [stdout] 19 | pub struct Dequeue<T> {
[INFO] [stdout]    |            ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated items `new`, `push_front`, and `get_from_front` are never used
[INFO] [stdout]   --> src/structures/dequeue.rs:25:12
[INFO] [stdout]    |
[INFO] [stdout] 24 | impl<T> Dequeue<T> {
[INFO] [stdout]    | ------------------ associated items in this implementation
[INFO] [stdout] 25 |     pub fn new() -> Self {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] ...
[INFO] [stdout] 32 |     pub fn push_front(&mut self, data: T)
[INFO] [stdout]    |            ^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 50 |     pub fn get_from_front(&self, index: usize) -> Rc<RefCell<T>> {
[INFO] [stdout]    |            ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `Link` is never used
[INFO] [stdout]  --> src/structures/linked_list.rs:3:10
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub enum Link<T>  {
[INFO] [stdout]   |          ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `LinkedNode` is never constructed
[INFO] [stdout]  --> src/structures/linked_list.rs:8:12
[INFO] [stdout]   |
[INFO] [stdout] 8 | pub struct LinkedNode<T> {
[INFO] [stdout]   |            ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated items `new` and `append` are never used
[INFO] [stdout]   --> src/structures/linked_list.rs:15:12
[INFO] [stdout]    |
[INFO] [stdout] 13 | impl <T> LinkedNode<T> {
[INFO] [stdout]    | ---------------------- associated items in this implementation
[INFO] [stdout] 14 |     
[INFO] [stdout] 15 |     pub fn new(data: T) -> Self{
[INFO] [stdout]    |            ^^^
[INFO] [stdout] ...
[INFO] [stdout] 19 |     pub fn append(&mut self, data: T) {
[INFO] [stdout]    |            ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `LinkedList` is never constructed
[INFO] [stdout]   --> src/structures/linked_list.rs:30:12
[INFO] [stdout]    |
[INFO] [stdout] 30 | pub struct LinkedList<T> {
[INFO] [stdout]    |            ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated items `new`, `append`, and `get` are never used
[INFO] [stdout]   --> src/structures/linked_list.rs:36:12
[INFO] [stdout]    |
[INFO] [stdout] 35 | impl <T> LinkedList<T> {
[INFO] [stdout]    | ---------------------- associated items in this implementation
[INFO] [stdout] 36 |     pub fn new() -> Self {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] ...
[INFO] [stdout] 40 |     pub fn append(&mut self, data: T) {
[INFO] [stdout]    |            ^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 53 |     pub fn get(&self, index: usize) -> Rc<RefCell<T>>{
[INFO] [stdout]    |            ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `BytesStorage` is never constructed
[INFO] [stdout]  --> src/structures/bytes_storage.rs:3:12
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub struct BytesStorage<'a> {
[INFO] [stdout]   |            ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: multiple associated items are never used
[INFO] [stdout]   --> src/structures/bytes_storage.rs:9:12
[INFO] [stdout]    |
[INFO] [stdout]  8 | impl<'a> BytesStorage<'a> {
[INFO] [stdout]    | ------------------------- associated items in this implementation
[INFO] [stdout]  9 |     pub fn new(bytes: &'a mut Vec<u8>) -> Self {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] ...
[INFO] [stdout] 14 |     pub fn set(&mut self, bytes: &'a mut Vec<u8>) {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] ...
[INFO] [stdout] 20 |     pub fn get(&self) -> &'_ Vec<u8> {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] ...
[INFO] [stdout] 24 |     pub fn len(&self) -> usize {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] ...
[INFO] [stdout] 28 |     pub fn or(&mut self, other: &Self) {
[INFO] [stdout]    |            ^^
[INFO] [stdout] ...
[INFO] [stdout] 37 |     pub fn and(&mut self, other: &Self) {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] ...
[INFO] [stdout] 46 |     pub fn xor(&mut self, other: &Self) {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `ExampleBox` is never constructed
[INFO] [stdout]  --> src/structures/example_box.rs:2:12
[INFO] [stdout]   |
[INFO] [stdout] 2 | pub struct ExampleBox<T: Display>(T);
[INFO] [stdout]   |            ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]  --> src/structures/example_box.rs:5:12
[INFO] [stdout]   |
[INFO] [stdout] 4 | impl <T: Display> ExampleBox<T> {
[INFO] [stdout]   | ------------------------------- associated function in this implementation
[INFO] [stdout] 5 |     pub fn new(x: T) -> Self {
[INFO] [stdout]   |            ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `Subscriber` is never used
[INFO] [stdout]  --> src/patterns/observer.rs:3:11
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub trait Subscriber<T: Clone> {
[INFO] [stdout]   |           ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `MessageSubscriber` is never constructed
[INFO] [stdout]  --> src/patterns/observer.rs:7:12
[INFO] [stdout]   |
[INFO] [stdout] 7 | pub struct MessageSubscriber {
[INFO] [stdout]   |            ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]   --> src/patterns/observer.rs:12:12
[INFO] [stdout]    |
[INFO] [stdout] 11 | impl MessageSubscriber {
[INFO] [stdout]    | ---------------------- associated function in this implementation
[INFO] [stdout] 12 |     pub fn new(message_placeholder: String) -> Self {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `Observer` is never used
[INFO] [stdout]   --> src/patterns/observer.rs:28:11
[INFO] [stdout]    |
[INFO] [stdout] 28 | pub trait Observer<'a, T: Clone> {
[INFO] [stdout]    |           ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `MessageObserver` is never constructed
[INFO] [stdout]   --> src/patterns/observer.rs:33:12
[INFO] [stdout]    |
[INFO] [stdout] 33 | pub struct MessageObserver<'a> {
[INFO] [stdout]    |            ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]   --> src/patterns/observer.rs:38:12
[INFO] [stdout]    |
[INFO] [stdout] 37 | impl <'a> MessageObserver<'a> {
[INFO] [stdout]    | ----------------------------- associated function in this implementation
[INFO] [stdout] 38 |     pub fn new() -> Self {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Cargo` is never constructed
[INFO] [stdout]  --> src/patterns/fabric.rs:3:12
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub struct Cargo {
[INFO] [stdout]   |            ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]  --> src/patterns/fabric.rs:9:12
[INFO] [stdout]   |
[INFO] [stdout] 8 | impl Cargo {
[INFO] [stdout]   | ---------- associated function in this implementation
[INFO] [stdout] 9 |     pub fn new(name: String, weight_kg: u32) -> Self {
[INFO] [stdout]   |            ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `Transport` is never used
[INFO] [stdout]   --> src/patterns/fabric.rs:14:11
[INFO] [stdout]    |
[INFO] [stdout] 14 | pub trait Transport {
[INFO] [stdout]    |           ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Taxi` is never constructed
[INFO] [stdout]   --> src/patterns/fabric.rs:18:12
[INFO] [stdout]    |
[INFO] [stdout] 18 | pub struct Taxi {
[INFO] [stdout]    |            ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Bus` is never constructed
[INFO] [stdout]   --> src/patterns/fabric.rs:31:12
[INFO] [stdout]    |
[INFO] [stdout] 31 | pub struct Bus {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `TransportFactory` is never constructed
[INFO] [stdout]   --> src/patterns/fabric.rs:44:12
[INFO] [stdout]    |
[INFO] [stdout] 44 | pub struct TransportFactory {}
[INFO] [stdout]    |            ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `create` is never used
[INFO] [stdout]   --> src/patterns/fabric.rs:47:12
[INFO] [stdout]    |
[INFO] [stdout] 46 | impl TransportFactory {
[INFO] [stdout]    | --------------------- associated function in this implementation
[INFO] [stdout] 47 |     pub fn create(
[INFO] [stdout]    |            ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `BadTransportTypeError` is never constructed
[INFO] [stdout]   --> src/patterns/fabric.rs:60:12
[INFO] [stdout]    |
[INFO] [stdout] 60 | pub struct BadTransportTypeError {}
[INFO] [stdout]    |            ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `List` is never used
[INFO] [stdout]  --> src/stdlib/pointers.rs:3:10
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub enum List {
[INFO] [stdout]   |          ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `some_action_with_value` is never used
[INFO] [stdout]  --> src/stdlib/pointers.rs:9:4
[INFO] [stdout]   |
[INFO] [stdout] 9 | fn some_action_with_value(value: &i32) {
[INFO] [stdout]   |    ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `iterate_list` is never used
[INFO] [stdout]   --> src/stdlib/pointers.rs:13:4
[INFO] [stdout]    |
[INFO] [stdout] 13 | fn iterate_list(current: Box<List>) {
[INFO] [stdout]    |    ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `simple_demo_box` is never used
[INFO] [stdout]   --> src/stdlib/pointers.rs:25:8
[INFO] [stdout]    |
[INFO] [stdout] 25 | pub fn simple_demo_box() {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `Tree` is never used
[INFO] [stdout]   --> src/stdlib/pointers.rs:31:10
[INFO] [stdout]    |
[INFO] [stdout] 31 | pub enum Tree {
[INFO] [stdout]    |          ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `iterate_tree` is never used
[INFO] [stdout]   --> src/stdlib/pointers.rs:36:4
[INFO] [stdout]    |
[INFO] [stdout] 36 | fn iterate_tree(root: Rc<Tree>) {
[INFO] [stdout]    |    ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `simple_demo_rc` is never used
[INFO] [stdout]   --> src/stdlib/pointers.rs:48:8
[INFO] [stdout]    |
[INFO] [stdout] 48 | pub fn simple_demo_rc() {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `Messenger` is never used
[INFO] [stdout]  --> src/stdlib/ref_cells.rs:3:11
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub trait Messenger {
[INFO] [stdout]   |           ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `LimitTracker` is never constructed
[INFO] [stdout]  --> src/stdlib/ref_cells.rs:7:12
[INFO] [stdout]   |
[INFO] [stdout] 7 | pub struct LimitTracker<'a, T: Messenger> {
[INFO] [stdout]   |            ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated items `new` and `set_value` are never used
[INFO] [stdout]   --> src/stdlib/ref_cells.rs:14:12
[INFO] [stdout]    |
[INFO] [stdout] 13 | impl <'a, T> LimitTracker<'a, T>  where T: Messenger {
[INFO] [stdout]    | ---------------------------------------------------- associated items in this implementation
[INFO] [stdout] 14 |     pub fn new(messenger: &'a T, max: usize) -> LimitTracker<'a, T> {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] ...
[INFO] [stdout] 18 |     pub fn set_value(&mut self, value: usize) {
[INFO] [stdout]    |            ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `AccumulativeMessenger` is never constructed
[INFO] [stdout]   --> src/stdlib/ref_cells.rs:29:8
[INFO] [stdout]    |
[INFO] [stdout] 29 | struct AccumulativeMessenger {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]   --> src/stdlib/ref_cells.rs:34:12
[INFO] [stdout]    |
[INFO] [stdout] 33 | impl  AccumulativeMessenger {
[INFO] [stdout]    | --------------------------- associated function in this implementation
[INFO] [stdout] 34 |     pub fn new() -> Self {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `ref_cell_demo` is never used
[INFO] [stdout]   --> src/stdlib/ref_cells.rs:45:8
[INFO] [stdout]    |
[INFO] [stdout] 45 | pub fn ref_cell_demo() {
[INFO] [stdout]    |        ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Tree` is never constructed
[INFO] [stdout]  --> src/stdlib/rc_refcell.rs:3:12
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub struct Tree {
[INFO] [stdout]   |            ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `AlreadyInTreeError` is never constructed
[INFO] [stdout]  --> src/stdlib/rc_refcell.rs:9:12
[INFO] [stdout]   |
[INFO] [stdout] 9 | pub struct AlreadyInTreeError {}
[INFO] [stdout]   |            ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated items `new`, `push`, and `traverse` are never used
[INFO] [stdout]   --> src/stdlib/rc_refcell.rs:12:12
[INFO] [stdout]    |
[INFO] [stdout] 11 | impl Tree {
[INFO] [stdout]    | --------- associated items in this implementation
[INFO] [stdout] 12 |     pub fn new(data: i32) -> Self {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] ...
[INFO] [stdout] 16 |     pub fn push(&self, data: i32) -> Result<i32, AlreadyInTreeError> {
[INFO] [stdout]    |            ^^^^
[INFO] [stdout] ...
[INFO] [stdout] 39 |     pub fn traverse(&self, apply_to_node_fn: fn(node: i32)) {
[INFO] [stdout]    |            ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]   --> src/structures/container.rs:44:17
[INFO] [stdout]    |
[INFO] [stdout] 44 |     pub fn iter(&self) -> Iter<T> {
[INFO] [stdout]    |                 ^^^^^     ^^^^^^^ the same lifetime is hidden here
[INFO] [stdout]    |                 |
[INFO] [stdout]    |                 the lifetime is elided here
[INFO] [stdout]    |
[INFO] [stdout]    = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout]    = note: `#[warn(mismatched_lifetime_syntaxes)]` on by default
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]    |
[INFO] [stdout] 44 |     pub fn iter(&self) -> Iter<'_, T> {
[INFO] [stdout]    |                                +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/stdlib/rc_refcell.rs:20:17
[INFO] [stdout]    |
[INFO] [stdout] 20 |                 right_node.push(data);
[INFO] [stdout]    |                 ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 20 |                 let _ = right_node.push(data);
[INFO] [stdout]    |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/stdlib/rc_refcell.rs:28:17
[INFO] [stdout]    |
[INFO] [stdout] 28 |                 left_node.push(data);
[INFO] [stdout]    |                 ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 28 |                 let _ = left_node.push(data);
[INFO] [stdout]    |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/stdlib/rc_refcell.rs:34:13
[INFO] [stdout]    |
[INFO] [stdout] 34 |             Err::<i32, AlreadyInTreeError>(AlreadyInTreeError{});
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 34 |             let _ = Err::<i32, AlreadyInTreeError>(AlreadyInTreeError{});
[INFO] [stdout]    |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.44s
[INFO] running `Command { std: "docker" "inspect" "e60e673849175780271eeab3b270116a1609ede7ff6459c2e1c09a7e06d3c2f3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e60e673849175780271eeab3b270116a1609ede7ff6459c2e1c09a7e06d3c2f3", kill_on_drop: false }`
[INFO] [stdout] e60e673849175780271eeab3b270116a1609ede7ff6459c2e1c09a7e06d3c2f3
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+c90bcb9571b7aab0d8beaa2ce8a998ffaf079d38" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 03407a2814dc63aae10da4498cc3c6acda28e8c81cb8983d48d6f0ce8372cfa9
[INFO] running `Command { std: "docker" "start" "-a" "03407a2814dc63aae10da4498cc3c6acda28e8c81cb8983d48d6f0ce8372cfa9", kill_on_drop: false }`
[INFO] [stderr]    Compiling rust-excercises v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `borrow::Borrow`
[INFO] [stdout]  --> src/structures/dequeue.rs:1:48
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::{cell::RefCell, fmt::Display, rc::Rc, borrow::Borrow};
[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: `vec`
[INFO] [stdout]  --> src/structures/bytes_storage.rs:1:25
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::{fmt::Display, vec};
[INFO] [stdout]   |                         ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: irrefutable `if let` pattern
[INFO] [stdout]   --> src/algorithms/binary_tree_inorder_traversal.rs:24:12
[INFO] [stdout]    |
[INFO] [stdout] 24 |         if let node = node.try_borrow().ok() {
[INFO] [stdout]    |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this pattern will always match, so the `if let` is useless
[INFO] [stdout]    = help: consider replacing the `if let` with a `let`
[INFO] [stdout]    = note: `#[warn(irrefutable_let_patterns)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `previous_result`
[INFO] [stdout]  --> src/algorithms/reverse_array.rs:8:9
[INFO] [stdout]   |
[INFO] [stdout] 8 |     let previous_result = replace(array, reversed);
[INFO] [stdout]   |         ^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_previous_result`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `TreeNode` is never constructed
[INFO] [stdout]  --> src/algorithms/binary_tree_inorder_traversal.rs:2:12
[INFO] [stdout]   |
[INFO] [stdout] 2 | pub struct TreeNode {
[INFO] [stdout]   |            ^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]   --> src/algorithms/binary_tree_inorder_traversal.rs:10:12
[INFO] [stdout]    |
[INFO] [stdout]  8 | impl TreeNode {
[INFO] [stdout]    | ------------- associated function in this implementation
[INFO] [stdout]  9 |     #[inline]
[INFO] [stdout] 10 |     pub fn new(val: i32) -> Self {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `inorder_traversal` is never used
[INFO] [stdout]   --> src/algorithms/binary_tree_inorder_traversal.rs:34:8
[INFO] [stdout]    |
[INFO] [stdout] 34 | pub fn inorder_traversal(root: Option<Rc<RefCell<TreeNode>>>) -> Vec<i32> {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `sorted_array_to_bst` is never used
[INFO] [stdout]  --> src/algorithms/convert_sorted_array_to_binary_search_tree.rs:8:8
[INFO] [stdout]   |
[INFO] [stdout] 8 | pub fn sorted_array_to_bst(nums: Vec<i32>) -> Option<Rc<RefCell<TreeNode>>> {
[INFO] [stdout]   |        ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `find_the_difference` is never used
[INFO] [stdout]  --> src/algorithms/find_the_difference.rs:1:8
[INFO] [stdout]   |
[INFO] [stdout] 1 | pub fn find_the_difference(s: String, t: String) -> char {
[INFO] [stdout]   |        ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `is_word_meets_criteria` is never used
[INFO] [stdout]  --> src/algorithms/find_words_that_can_be_formed_by_characters.rs:3:4
[INFO] [stdout]   |
[INFO] [stdout] 3 | fn is_word_meets_criteria(word: &String, mut criteria: HashMap<char, u8>) -> bool {
[INFO] [stdout]   |    ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `count_characters` is never used
[INFO] [stdout]   --> src/algorithms/find_words_that_can_be_formed_by_characters.rs:17:8
[INFO] [stdout]    |
[INFO] [stdout] 17 | pub fn count_characters(words: Vec<String>, chars: String) -> i32 {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `first_uniq_char` is never used
[INFO] [stdout]  --> src/algorithms/first_unique_character_in_a_string.rs:3:8
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub fn first_uniq_char(s: String) -> i32 {
[INFO] [stdout]   |        ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `get_squared_sum` is never used
[INFO] [stdout]  --> src/algorithms/is_happy.rs:3:8
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub fn get_squared_sum(number: i32) -> i32 {
[INFO] [stdout]   |        ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `is_happy` is never used
[INFO] [stdout]   --> src/algorithms/is_happy.rs:13:8
[INFO] [stdout]    |
[INFO] [stdout] 13 | pub fn is_happy(n: i32) -> bool {
[INFO] [stdout]    |        ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `longest_common_prefix` is never used
[INFO] [stdout]  --> src/algorithms/longest_common_prefix.rs:3:8
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub fn longest_common_prefix(strs: Vec<String>) -> String {
[INFO] [stdout]   |        ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `majority_element` is never used
[INFO] [stdout]  --> src/algorithms/majority_element.rs:3:8
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub fn majority_element(nums: Vec<i32>) -> i32 {
[INFO] [stdout]   |        ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `ListNode` is never constructed
[INFO] [stdout]  --> src/algorithms/palindrome_linked_list.rs:2:12
[INFO] [stdout]   |
[INFO] [stdout] 2 | pub struct ListNode {
[INFO] [stdout]   |            ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]  --> src/algorithms/palindrome_linked_list.rs:9:8
[INFO] [stdout]   |
[INFO] [stdout] 7 | impl ListNode {
[INFO] [stdout]   | ------------- associated function in this implementation
[INFO] [stdout] 8 |     #[inline]
[INFO] [stdout] 9 |     fn new(val: i32) -> Self {
[INFO] [stdout]   |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `is_palindrome` is never used
[INFO] [stdout]   --> src/algorithms/palindrome_linked_list.rs:18:8
[INFO] [stdout]    |
[INFO] [stdout] 18 | pub fn is_palindrome(head: Option<Box<ListNode>>) -> bool {
[INFO] [stdout]    |        ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `build_reverse` is never used
[INFO] [stdout]   --> src/algorithms/palindrome_linked_list.rs:39:8
[INFO] [stdout]    |
[INFO] [stdout] 39 | pub fn build_reverse(head: &mut Option<Box<ListNode>>) -> Option<Box<ListNode>> {
[INFO] [stdout]    |        ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `is_palindrome` is never used
[INFO] [stdout]  --> src/algorithms/palindrome_number.rs:1:8
[INFO] [stdout]   |
[INFO] [stdout] 1 | pub fn is_palindrome(x: i32) -> bool {
[INFO] [stdout]   |        ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `pascal_triangle` is never used
[INFO] [stdout]  --> src/algorithms/pascal_triangle.rs:1:8
[INFO] [stdout]   |
[INFO] [stdout] 1 | pub fn pascal_triangle(num_rows: u32) -> Vec<Vec<i32>> {
[INFO] [stdout]   |        ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `roman_to_int` is never used
[INFO] [stdout]  --> src/algorithms/roman_to_integer.rs:3:8
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub fn roman_to_int(s: String) -> i32 {
[INFO] [stdout]   |        ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `search_insert` is never used
[INFO] [stdout]   --> src/algorithms/search_insert_position.rs:29:8
[INFO] [stdout]    |
[INFO] [stdout] 29 | pub fn search_insert(nums: Vec<i32>, target: i32) -> i32 {
[INFO] [stdout]    |        ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `two_sum` is never used
[INFO] [stdout]  --> src/algorithms/two_sum.rs:1:8
[INFO] [stdout]   |
[INFO] [stdout] 1 | pub fn two_sum(nums: Vec<i32>, target: i32) -> Vec<i32> {
[INFO] [stdout]   |        ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `get_closing_parenthesis` is never used
[INFO] [stdout]  --> src/algorithms/valid_parentheses.rs:1:4
[INFO] [stdout]   |
[INFO] [stdout] 1 | fn get_closing_parenthesis(opening_parenthesis: &char) -> Option<char> {
[INFO] [stdout]   |    ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `is_valid` is never used
[INFO] [stdout]   --> src/algorithms/valid_parentheses.rs:10:8
[INFO] [stdout]    |
[INFO] [stdout] 10 | pub fn is_valid(s: String) -> bool {
[INFO] [stdout]    |        ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `first_earlier_than_second` is never used
[INFO] [stdout]  --> src/algorithms/verifying_an_alien_dictionary.rs:3:8
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub fn first_earlier_than_second(first: &String, second: &String, dictionary: &HashMap<char, usize>) -> bool {
[INFO] [stdout]   |        ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `is_alien_sorted` is never used
[INFO] [stdout]   --> src/algorithms/verifying_an_alien_dictionary.rs:26:8
[INFO] [stdout]    |
[INFO] [stdout] 26 | pub fn is_alien_sorted(words: Vec<String>, order: String) -> bool {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `reverse_array` is never used
[INFO] [stdout]  --> src/algorithms/reverse_array.rs:3:8
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub fn reverse_array<T: Default>(array: &mut Vec<T>) {
[INFO] [stdout]   |        ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Container` is never constructed
[INFO] [stdout]  --> src/structures/container.rs:3:12
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub struct Container<T: Eq + Hash + Clone> {
[INFO] [stdout]   |            ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated items `new`, `push`, `get`, `get_unique_items_count`, `get_size`, and `iter` are never used
[INFO] [stdout]   --> src/structures/container.rs:11:12
[INFO] [stdout]    |
[INFO] [stdout] 10 | impl <T: Eq + Hash + Clone> Container<T> {
[INFO] [stdout]    | ---------------------------------------- associated items in this implementation
[INFO] [stdout] 11 |     pub fn new() -> Self {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] ...
[INFO] [stdout] 20 |     pub fn push(&mut self, item: T) {
[INFO] [stdout]    |            ^^^^
[INFO] [stdout] ...
[INFO] [stdout] 32 |     pub fn get(&self, index: usize) -> Option<&T> {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] ...
[INFO] [stdout] 36 |     pub fn get_unique_items_count(&self) -> usize {
[INFO] [stdout]    |            ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 40 |     pub fn get_size(&self) -> usize {
[INFO] [stdout]    |            ^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 44 |     pub fn iter(&self) -> Iter<T> {
[INFO] [stdout]    |            ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `DequeueNode` is never constructed
[INFO] [stdout]  --> src/structures/dequeue.rs:3:12
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub struct DequeueNode<T> {
[INFO] [stdout]   |            ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]   --> src/structures/dequeue.rs:10:12
[INFO] [stdout]    |
[INFO] [stdout]  9 | impl<T> DequeueNode<T> {
[INFO] [stdout]    | ---------------------- associated function in this implementation
[INFO] [stdout] 10 |     pub fn new(data: T) -> Self {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Dequeue` is never constructed
[INFO] [stdout]   --> src/structures/dequeue.rs:19:12
[INFO] [stdout]    |
[INFO] [stdout] 19 | pub struct Dequeue<T> {
[INFO] [stdout]    |            ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated items `new`, `push_front`, and `get_from_front` are never used
[INFO] [stdout]   --> src/structures/dequeue.rs:25:12
[INFO] [stdout]    |
[INFO] [stdout] 24 | impl<T> Dequeue<T> {
[INFO] [stdout]    | ------------------ associated items in this implementation
[INFO] [stdout] 25 |     pub fn new() -> Self {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] ...
[INFO] [stdout] 32 |     pub fn push_front(&mut self, data: T)
[INFO] [stdout]    |            ^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 50 |     pub fn get_from_front(&self, index: usize) -> Rc<RefCell<T>> {
[INFO] [stdout]    |            ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `Link` is never used
[INFO] [stdout]  --> src/structures/linked_list.rs:3:10
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub enum Link<T>  {
[INFO] [stdout]   |          ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `LinkedNode` is never constructed
[INFO] [stdout]  --> src/structures/linked_list.rs:8:12
[INFO] [stdout]   |
[INFO] [stdout] 8 | pub struct LinkedNode<T> {
[INFO] [stdout]   |            ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated items `new` and `append` are never used
[INFO] [stdout]   --> src/structures/linked_list.rs:15:12
[INFO] [stdout]    |
[INFO] [stdout] 13 | impl <T> LinkedNode<T> {
[INFO] [stdout]    | ---------------------- associated items in this implementation
[INFO] [stdout] 14 |     
[INFO] [stdout] 15 |     pub fn new(data: T) -> Self{
[INFO] [stdout]    |            ^^^
[INFO] [stdout] ...
[INFO] [stdout] 19 |     pub fn append(&mut self, data: T) {
[INFO] [stdout]    |            ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `LinkedList` is never constructed
[INFO] [stdout]   --> src/structures/linked_list.rs:30:12
[INFO] [stdout]    |
[INFO] [stdout] 30 | pub struct LinkedList<T> {
[INFO] [stdout]    |            ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated items `new`, `append`, and `get` are never used
[INFO] [stdout]   --> src/structures/linked_list.rs:36:12
[INFO] [stdout]    |
[INFO] [stdout] 35 | impl <T> LinkedList<T> {
[INFO] [stdout]    | ---------------------- associated items in this implementation
[INFO] [stdout] 36 |     pub fn new() -> Self {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] ...
[INFO] [stdout] 40 |     pub fn append(&mut self, data: T) {
[INFO] [stdout]    |            ^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 53 |     pub fn get(&self, index: usize) -> Rc<RefCell<T>>{
[INFO] [stdout]    |            ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `BytesStorage` is never constructed
[INFO] [stdout]  --> src/structures/bytes_storage.rs:3:12
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub struct BytesStorage<'a> {
[INFO] [stdout]   |            ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: multiple associated items are never used
[INFO] [stdout]   --> src/structures/bytes_storage.rs:9:12
[INFO] [stdout]    |
[INFO] [stdout]  8 | impl<'a> BytesStorage<'a> {
[INFO] [stdout]    | ------------------------- associated items in this implementation
[INFO] [stdout]  9 |     pub fn new(bytes: &'a mut Vec<u8>) -> Self {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] ...
[INFO] [stdout] 14 |     pub fn set(&mut self, bytes: &'a mut Vec<u8>) {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] ...
[INFO] [stdout] 20 |     pub fn get(&self) -> &'_ Vec<u8> {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] ...
[INFO] [stdout] 24 |     pub fn len(&self) -> usize {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] ...
[INFO] [stdout] 28 |     pub fn or(&mut self, other: &Self) {
[INFO] [stdout]    |            ^^
[INFO] [stdout] ...
[INFO] [stdout] 37 |     pub fn and(&mut self, other: &Self) {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] ...
[INFO] [stdout] 46 |     pub fn xor(&mut self, other: &Self) {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `ExampleBox` is never constructed
[INFO] [stdout]  --> src/structures/example_box.rs:2:12
[INFO] [stdout]   |
[INFO] [stdout] 2 | pub struct ExampleBox<T: Display>(T);
[INFO] [stdout]   |            ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]  --> src/structures/example_box.rs:5:12
[INFO] [stdout]   |
[INFO] [stdout] 4 | impl <T: Display> ExampleBox<T> {
[INFO] [stdout]   | ------------------------------- associated function in this implementation
[INFO] [stdout] 5 |     pub fn new(x: T) -> Self {
[INFO] [stdout]   |            ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `Subscriber` is never used
[INFO] [stdout]  --> src/patterns/observer.rs:3:11
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub trait Subscriber<T: Clone> {
[INFO] [stdout]   |           ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `MessageSubscriber` is never constructed
[INFO] [stdout]  --> src/patterns/observer.rs:7:12
[INFO] [stdout]   |
[INFO] [stdout] 7 | pub struct MessageSubscriber {
[INFO] [stdout]   |            ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]   --> src/patterns/observer.rs:12:12
[INFO] [stdout]    |
[INFO] [stdout] 11 | impl MessageSubscriber {
[INFO] [stdout]    | ---------------------- associated function in this implementation
[INFO] [stdout] 12 |     pub fn new(message_placeholder: String) -> Self {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `Observer` is never used
[INFO] [stdout]   --> src/patterns/observer.rs:28:11
[INFO] [stdout]    |
[INFO] [stdout] 28 | pub trait Observer<'a, T: Clone> {
[INFO] [stdout]    |           ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `MessageObserver` is never constructed
[INFO] [stdout]   --> src/patterns/observer.rs:33:12
[INFO] [stdout]    |
[INFO] [stdout] 33 | pub struct MessageObserver<'a> {
[INFO] [stdout]    |            ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]   --> src/patterns/observer.rs:38:12
[INFO] [stdout]    |
[INFO] [stdout] 37 | impl <'a> MessageObserver<'a> {
[INFO] [stdout]    | ----------------------------- associated function in this implementation
[INFO] [stdout] 38 |     pub fn new() -> Self {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Cargo` is never constructed
[INFO] [stdout]  --> src/patterns/fabric.rs:3:12
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub struct Cargo {
[INFO] [stdout]   |            ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]  --> src/patterns/fabric.rs:9:12
[INFO] [stdout]   |
[INFO] [stdout] 8 | impl Cargo {
[INFO] [stdout]   | ---------- associated function in this implementation
[INFO] [stdout] 9 |     pub fn new(name: String, weight_kg: u32) -> Self {
[INFO] [stdout]   |            ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `Transport` is never used
[INFO] [stdout]   --> src/patterns/fabric.rs:14:11
[INFO] [stdout]    |
[INFO] [stdout] 14 | pub trait Transport {
[INFO] [stdout]    |           ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Taxi` is never constructed
[INFO] [stdout]   --> src/patterns/fabric.rs:18:12
[INFO] [stdout]    |
[INFO] [stdout] 18 | pub struct Taxi {
[INFO] [stdout]    |            ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Bus` is never constructed
[INFO] [stdout]   --> src/patterns/fabric.rs:31:12
[INFO] [stdout]    |
[INFO] [stdout] 31 | pub struct Bus {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `TransportFactory` is never constructed
[INFO] [stdout]   --> src/patterns/fabric.rs:44:12
[INFO] [stdout]    |
[INFO] [stdout] 44 | pub struct TransportFactory {}
[INFO] [stdout]    |            ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `create` is never used
[INFO] [stdout]   --> src/patterns/fabric.rs:47:12
[INFO] [stdout]    |
[INFO] [stdout] 46 | impl TransportFactory {
[INFO] [stdout]    | --------------------- associated function in this implementation
[INFO] [stdout] 47 |     pub fn create(
[INFO] [stdout]    |            ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `BadTransportTypeError` is never constructed
[INFO] [stdout]   --> src/patterns/fabric.rs:60:12
[INFO] [stdout]    |
[INFO] [stdout] 60 | pub struct BadTransportTypeError {}
[INFO] [stdout]    |            ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `List` is never used
[INFO] [stdout]  --> src/stdlib/pointers.rs:3:10
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub enum List {
[INFO] [stdout]   |          ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `some_action_with_value` is never used
[INFO] [stdout]  --> src/stdlib/pointers.rs:9:4
[INFO] [stdout]   |
[INFO] [stdout] 9 | fn some_action_with_value(value: &i32) {
[INFO] [stdout]   |    ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `iterate_list` is never used
[INFO] [stdout]   --> src/stdlib/pointers.rs:13:4
[INFO] [stdout]    |
[INFO] [stdout] 13 | fn iterate_list(current: Box<List>) {
[INFO] [stdout]    |    ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `simple_demo_box` is never used
[INFO] [stdout]   --> src/stdlib/pointers.rs:25:8
[INFO] [stdout]    |
[INFO] [stdout] 25 | pub fn simple_demo_box() {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `Tree` is never used
[INFO] [stdout]   --> src/stdlib/pointers.rs:31:10
[INFO] [stdout]    |
[INFO] [stdout] 31 | pub enum Tree {
[INFO] [stdout]    |          ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `iterate_tree` is never used
[INFO] [stdout]   --> src/stdlib/pointers.rs:36:4
[INFO] [stdout]    |
[INFO] [stdout] 36 | fn iterate_tree(root: Rc<Tree>) {
[INFO] [stdout]    |    ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `simple_demo_rc` is never used
[INFO] [stdout]   --> src/stdlib/pointers.rs:48:8
[INFO] [stdout]    |
[INFO] [stdout] 48 | pub fn simple_demo_rc() {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `Messenger` is never used
[INFO] [stdout]  --> src/stdlib/ref_cells.rs:3:11
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub trait Messenger {
[INFO] [stdout]   |           ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `LimitTracker` is never constructed
[INFO] [stdout]  --> src/stdlib/ref_cells.rs:7:12
[INFO] [stdout]   |
[INFO] [stdout] 7 | pub struct LimitTracker<'a, T: Messenger> {
[INFO] [stdout]   |            ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated items `new` and `set_value` are never used
[INFO] [stdout]   --> src/stdlib/ref_cells.rs:14:12
[INFO] [stdout]    |
[INFO] [stdout] 13 | impl <'a, T> LimitTracker<'a, T>  where T: Messenger {
[INFO] [stdout]    | ---------------------------------------------------- associated items in this implementation
[INFO] [stdout] 14 |     pub fn new(messenger: &'a T, max: usize) -> LimitTracker<'a, T> {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] ...
[INFO] [stdout] 18 |     pub fn set_value(&mut self, value: usize) {
[INFO] [stdout]    |            ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `AccumulativeMessenger` is never constructed
[INFO] [stdout]   --> src/stdlib/ref_cells.rs:29:8
[INFO] [stdout]    |
[INFO] [stdout] 29 | struct AccumulativeMessenger {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `new` is never used
[INFO] [stdout]   --> src/stdlib/ref_cells.rs:34:12
[INFO] [stdout]    |
[INFO] [stdout] 33 | impl  AccumulativeMessenger {
[INFO] [stdout]    | --------------------------- associated function in this implementation
[INFO] [stdout] 34 |     pub fn new() -> Self {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `ref_cell_demo` is never used
[INFO] [stdout]   --> src/stdlib/ref_cells.rs:45:8
[INFO] [stdout]    |
[INFO] [stdout] 45 | pub fn ref_cell_demo() {
[INFO] [stdout]    |        ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `Tree` is never constructed
[INFO] [stdout]  --> src/stdlib/rc_refcell.rs:3:12
[INFO] [stdout]   |
[INFO] [stdout] 3 | pub struct Tree {
[INFO] [stdout]   |            ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `AlreadyInTreeError` is never constructed
[INFO] [stdout]  --> src/stdlib/rc_refcell.rs:9:12
[INFO] [stdout]   |
[INFO] [stdout] 9 | pub struct AlreadyInTreeError {}
[INFO] [stdout]   |            ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated items `new`, `push`, and `traverse` are never used
[INFO] [stdout]   --> src/stdlib/rc_refcell.rs:12:12
[INFO] [stdout]    |
[INFO] [stdout] 11 | impl Tree {
[INFO] [stdout]    | --------- associated items in this implementation
[INFO] [stdout] 12 |     pub fn new(data: i32) -> Self {
[INFO] [stdout]    |            ^^^
[INFO] [stdout] ...
[INFO] [stdout] 16 |     pub fn push(&self, data: i32) -> Result<i32, AlreadyInTreeError> {
[INFO] [stdout]    |            ^^^^
[INFO] [stdout] ...
[INFO] [stdout] 39 |     pub fn traverse(&self, apply_to_node_fn: fn(node: i32)) {
[INFO] [stdout]    |            ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]   --> src/structures/container.rs:44:17
[INFO] [stdout]    |
[INFO] [stdout] 44 |     pub fn iter(&self) -> Iter<T> {
[INFO] [stdout]    |                 ^^^^^     ^^^^^^^ the same lifetime is hidden here
[INFO] [stdout]    |                 |
[INFO] [stdout]    |                 the lifetime is elided here
[INFO] [stdout]    |
[INFO] [stdout]    = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout]    = note: `#[warn(mismatched_lifetime_syntaxes)]` on by default
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]    |
[INFO] [stdout] 44 |     pub fn iter(&self) -> Iter<'_, T> {
[INFO] [stdout]    |                                +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/stdlib/rc_refcell.rs:20:17
[INFO] [stdout]    |
[INFO] [stdout] 20 |                 right_node.push(data);
[INFO] [stdout]    |                 ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 20 |                 let _ = right_node.push(data);
[INFO] [stdout]    |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/stdlib/rc_refcell.rs:28:17
[INFO] [stdout]    |
[INFO] [stdout] 28 |                 left_node.push(data);
[INFO] [stdout]    |                 ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 28 |                 let _ = left_node.push(data);
[INFO] [stdout]    |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/stdlib/rc_refcell.rs:34:13
[INFO] [stdout]    |
[INFO] [stdout] 34 |             Err::<i32, AlreadyInTreeError>(AlreadyInTreeError{});
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 34 |             let _ = Err::<i32, AlreadyInTreeError>(AlreadyInTreeError{});
[INFO] [stdout]    |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.53s
[INFO] running `Command { std: "docker" "inspect" "03407a2814dc63aae10da4498cc3c6acda28e8c81cb8983d48d6f0ce8372cfa9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "03407a2814dc63aae10da4498cc3c6acda28e8c81cb8983d48d6f0ce8372cfa9", kill_on_drop: false }`
[INFO] [stdout] 03407a2814dc63aae10da4498cc3c6acda28e8c81cb8983d48d6f0ce8372cfa9
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+c90bcb9571b7aab0d8beaa2ce8a998ffaf079d38" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 1ced85b770812ef6699f9cc413db734c480da47abf93239eed0a83a98e4ca56c
[INFO] running `Command { std: "docker" "start" "-a" "1ced85b770812ef6699f9cc413db734c480da47abf93239eed0a83a98e4ca56c", kill_on_drop: false }`
[INFO] [stderr] warning: unused import: `borrow::Borrow`
[INFO] [stderr]  --> src/structures/dequeue.rs:1:48
[INFO] [stderr]   |
[INFO] [stderr] 1 | use std::{cell::RefCell, fmt::Display, rc::Rc, borrow::Borrow};
[INFO] [stderr]   |                                                ^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `vec`
[INFO] [stderr]  --> src/structures/bytes_storage.rs:1:25
[INFO] [stderr]   |
[INFO] [stderr] 1 | use std::{fmt::Display, vec};
[INFO] [stderr]   |                         ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: irrefutable `if let` pattern
[INFO] [stderr]   --> src/algorithms/binary_tree_inorder_traversal.rs:24:12
[INFO] [stderr]    |
[INFO] [stderr] 24 |         if let node = node.try_borrow().ok() {
[INFO] [stderr]    |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: this pattern will always match, so the `if let` is useless
[INFO] [stderr]    = help: consider replacing the `if let` with a `let`
[INFO] [stderr]    = note: `#[warn(irrefutable_let_patterns)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `previous_result`
[INFO] [stderr]  --> src/algorithms/reverse_array.rs:8:9
[INFO] [stderr]   |
[INFO] [stderr] 8 |     let previous_result = replace(array, reversed);
[INFO] [stderr]   |         ^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_previous_result`
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stderr] 
[INFO] [stderr] warning: struct `TreeNode` is never constructed
[INFO] [stderr]  --> src/algorithms/binary_tree_inorder_traversal.rs:2:12
[INFO] [stderr]   |
[INFO] [stderr] 2 | pub struct TreeNode {
[INFO] [stderr]   |            ^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stderr] 
[INFO] [stderr] warning: associated function `new` is never used
[INFO] [stderr]   --> src/algorithms/binary_tree_inorder_traversal.rs:10:12
[INFO] [stderr]    |
[INFO] [stderr]  8 | impl TreeNode {
[INFO] [stderr]    | ------------- associated function in this implementation
[INFO] [stderr]  9 |     #[inline]
[INFO] [stderr] 10 |     pub fn new(val: i32) -> Self {
[INFO] [stderr]    |            ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `inorder_traversal` is never used
[INFO] [stderr]   --> src/algorithms/binary_tree_inorder_traversal.rs:34:8
[INFO] [stderr]    |
[INFO] [stderr] 34 | pub fn inorder_traversal(root: Option<Rc<RefCell<TreeNode>>>) -> Vec<i32> {
[INFO] [stderr]    |        ^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `sorted_array_to_bst` is never used
[INFO] [stderr]  --> src/algorithms/convert_sorted_array_to_binary_search_tree.rs:8:8
[INFO] [stderr]   |
[INFO] [stderr] 8 | pub fn sorted_array_to_bst(nums: Vec<i32>) -> Option<Rc<RefCell<TreeNode>>> {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `find_the_difference` is never used
[INFO] [stderr]  --> src/algorithms/find_the_difference.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn find_the_difference(s: String, t: String) -> char {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `is_word_meets_criteria` is never used
[INFO] [stderr]  --> src/algorithms/find_words_that_can_be_formed_by_characters.rs:3:4
[INFO] [stderr]   |
[INFO] [stderr] 3 | fn is_word_meets_criteria(word: &String, mut criteria: HashMap<char, u8>) -> bool {
[INFO] [stderr]   |    ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `count_characters` is never used
[INFO] [stderr]   --> src/algorithms/find_words_that_can_be_formed_by_characters.rs:17:8
[INFO] [stderr]    |
[INFO] [stderr] 17 | pub fn count_characters(words: Vec<String>, chars: String) -> i32 {
[INFO] [stderr]    |        ^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `first_uniq_char` is never used
[INFO] [stderr]  --> src/algorithms/first_unique_character_in_a_string.rs:3:8
[INFO] [stderr]   |
[INFO] [stderr] 3 | pub fn first_uniq_char(s: String) -> i32 {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `get_squared_sum` is never used
[INFO] [stderr]  --> src/algorithms/is_happy.rs:3:8
[INFO] [stderr]   |
[INFO] [stderr] 3 | pub fn get_squared_sum(number: i32) -> i32 {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `is_happy` is never used
[INFO] [stderr]   --> src/algorithms/is_happy.rs:13:8
[INFO] [stderr]    |
[INFO] [stderr] 13 | pub fn is_happy(n: i32) -> bool {
[INFO] [stderr]    |        ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `longest_common_prefix` is never used
[INFO] [stderr]  --> src/algorithms/longest_common_prefix.rs:3:8
[INFO] [stderr]   |
[INFO] [stderr] 3 | pub fn longest_common_prefix(strs: Vec<String>) -> String {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `majority_element` is never used
[INFO] [stderr]  --> src/algorithms/majority_element.rs:3:8
[INFO] [stderr]   |
[INFO] [stderr] 3 | pub fn majority_element(nums: Vec<i32>) -> i32 {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct `ListNode` is never constructed
[INFO] [stderr]  --> src/algorithms/palindrome_linked_list.rs:2:12
[INFO] [stderr]   |
[INFO] [stderr] 2 | pub struct ListNode {
[INFO] [stderr]   |            ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function `new` is never used
[INFO] [stderr]  --> src/algorithms/palindrome_linked_list.rs:9:8
[INFO] [stderr]   |
[INFO] [stderr] 7 | impl ListNode {
[INFO] [stderr]   | ------------- associated function in this implementation
[INFO] [stderr] 8 |     #[inline]
[INFO] [stderr] 9 |     fn new(val: i32) -> Self {
[INFO] [stderr]   |        ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `is_palindrome` is never used
[INFO] [stderr]   --> src/algorithms/palindrome_linked_list.rs:18:8
[INFO] [stderr]    |
[INFO] [stderr] 18 | pub fn is_palindrome(head: Option<Box<ListNode>>) -> bool {
[INFO] [stderr]    |        ^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `build_reverse` is never used
[INFO] [stderr]   --> src/algorithms/palindrome_linked_list.rs:39:8
[INFO] [stderr]    |
[INFO] [stderr] 39 | pub fn build_reverse(head: &mut Option<Box<ListNode>>) -> Option<Box<ListNode>> {
[INFO] [stderr]    |        ^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `is_palindrome` is never used
[INFO] [stderr]  --> src/algorithms/palindrome_number.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn is_palindrome(x: i32) -> bool {
[INFO] [stderr]   |        ^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `pascal_triangle` is never used
[INFO] [stderr]  --> src/algorithms/pascal_triangle.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn pascal_triangle(num_rows: u32) -> Vec<Vec<i32>> {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `roman_to_int` is never used
[INFO] [stderr]  --> src/algorithms/roman_to_integer.rs:3:8
[INFO] [stderr]   |
[INFO] [stderr] 3 | pub fn roman_to_int(s: String) -> i32 {
[INFO] [stderr]   |        ^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `search_insert` is never used
[INFO] [stderr]   --> src/algorithms/search_insert_position.rs:29:8
[INFO] [stderr]    |
[INFO] [stderr] 29 | pub fn search_insert(nums: Vec<i32>, target: i32) -> i32 {
[INFO] [stderr]    |        ^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `two_sum` is never used
[INFO] [stderr]  --> src/algorithms/two_sum.rs:1:8
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub fn two_sum(nums: Vec<i32>, target: i32) -> Vec<i32> {
[INFO] [stderr]   |        ^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `get_closing_parenthesis` is never used
[INFO] [stderr]  --> src/algorithms/valid_parentheses.rs:1:4
[INFO] [stderr]   |
[INFO] [stderr] 1 | fn get_closing_parenthesis(opening_parenthesis: &char) -> Option<char> {
[INFO] [stderr]   |    ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `is_valid` is never used
[INFO] [stderr]   --> src/algorithms/valid_parentheses.rs:10:8
[INFO] [stderr]    |
[INFO] [stderr] 10 | pub fn is_valid(s: String) -> bool {
[INFO] [stderr]    |        ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `first_earlier_than_second` is never used
[INFO] [stderr]  --> src/algorithms/verifying_an_alien_dictionary.rs:3:8
[INFO] [stderr]   |
[INFO] [stderr] 3 | pub fn first_earlier_than_second(first: &String, second: &String, dictionary: &HashMap<char, usize>) -> bool {
[INFO] [stderr]   |        ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `is_alien_sorted` is never used
[INFO] [stderr]   --> src/algorithms/verifying_an_alien_dictionary.rs:26:8
[INFO] [stderr]    |
[INFO] [stderr] 26 | pub fn is_alien_sorted(words: Vec<String>, order: String) -> bool {
[INFO] [stderr]    |        ^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `reverse_array` is never used
[INFO] [stderr]  --> src/algorithms/reverse_array.rs:3:8
[INFO] [stderr]   |
[INFO] [stderr] 3 | pub fn reverse_array<T: Default>(array: &mut Vec<T>) {
[INFO] [stderr]   |        ^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct `Container` is never constructed
[INFO] [stderr]  --> src/structures/container.rs:3:12
[INFO] [stderr]   |
[INFO] [stderr] 3 | pub struct Container<T: Eq + Hash + Clone> {
[INFO] [stderr]   |            ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated items `new`, `push`, `get`, `get_unique_items_count`, `get_size`, and `iter` are never used
[INFO] [stderr]   --> src/structures/container.rs:11:12
[INFO] [stderr]    |
[INFO] [stderr] 10 | impl <T: Eq + Hash + Clone> Container<T> {
[INFO] [stderr]    | ---------------------------------------- associated items in this implementation
[INFO] [stderr] 11 |     pub fn new() -> Self {
[INFO] [stderr]    |            ^^^
[INFO] [stderr] ...
[INFO] [stderr] 20 |     pub fn push(&mut self, item: T) {
[INFO] [stderr]    |            ^^^^
[INFO] [stderr] ...
[INFO] [stderr] 32 |     pub fn get(&self, index: usize) -> Option<&T> {
[INFO] [stderr]    |            ^^^
[INFO] [stderr] ...
[INFO] [stderr] 36 |     pub fn get_unique_items_count(&self) -> usize {
[INFO] [stderr]    |            ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] ...
[INFO] [stderr] 40 |     pub fn get_size(&self) -> usize {
[INFO] [stderr]    |            ^^^^^^^^
[INFO] [stderr] ...
[INFO] [stderr] 44 |     pub fn iter(&self) -> Iter<T> {
[INFO] [stderr]    |            ^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct `DequeueNode` is never constructed
[INFO] [stderr]  --> src/structures/dequeue.rs:3:12
[INFO] [stderr]   |
[INFO] [stderr] 3 | pub struct DequeueNode<T> {
[INFO] [stderr]   |            ^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function `new` is never used
[INFO] [stderr]   --> src/structures/dequeue.rs:10:12
[INFO] [stderr]    |
[INFO] [stderr]  9 | impl<T> DequeueNode<T> {
[INFO] [stderr]    | ---------------------- associated function in this implementation
[INFO] [stderr] 10 |     pub fn new(data: T) -> Self {
[INFO] [stderr]    |            ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct `Dequeue` is never constructed
[INFO] [stderr]   --> src/structures/dequeue.rs:19:12
[INFO] [stderr]    |
[INFO] [stderr] 19 | pub struct Dequeue<T> {
[INFO] [stderr]    |            ^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated items `new`, `push_front`, and `get_from_front` are never used
[INFO] [stderr]   --> src/structures/dequeue.rs:25:12
[INFO] [stderr]    |
[INFO] [stderr] 24 | impl<T> Dequeue<T> {
[INFO] [stderr]    | ------------------ associated items in this implementation
[INFO] [stderr] 25 |     pub fn new() -> Self {
[INFO] [stderr]    |            ^^^
[INFO] [stderr] ...
[INFO] [stderr] 32 |     pub fn push_front(&mut self, data: T)
[INFO] [stderr]    |            ^^^^^^^^^^
[INFO] [stderr] ...
[INFO] [stderr] 50 |     pub fn get_from_front(&self, index: usize) -> Rc<RefCell<T>> {
[INFO] [stderr]    |            ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: enum `Link` is never used
[INFO] [stderr]  --> src/structures/linked_list.rs:3:10
[INFO] [stderr]   |
[INFO] [stderr] 3 | pub enum Link<T>  {
[INFO] [stderr]   |          ^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct `LinkedNode` is never constructed
[INFO] [stderr]  --> src/structures/linked_list.rs:8:12
[INFO] [stderr]   |
[INFO] [stderr] 8 | pub struct LinkedNode<T> {
[INFO] [stderr]   |            ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated items `new` and `append` are never used
[INFO] [stderr]   --> src/structures/linked_list.rs:15:12
[INFO] [stderr]    |
[INFO] [stderr] 13 | impl <T> LinkedNode<T> {
[INFO] [stderr]    | ---------------------- associated items in this implementation
[INFO] [stderr] 14 |     
[INFO] [stderr] 15 |     pub fn new(data: T) -> Self{
[INFO] [stderr]    |            ^^^
[INFO] [stderr] ...
[INFO] [stderr] 19 |     pub fn append(&mut self, data: T) {
[INFO] [stderr]    |            ^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct `LinkedList` is never constructed
[INFO] [stderr]   --> src/structures/linked_list.rs:30:12
[INFO] [stderr]    |
[INFO] [stderr] 30 | pub struct LinkedList<T> {
[INFO] [stderr]    |            ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated items `new`, `append`, and `get` are never used
[INFO] [stderr]   --> src/structures/linked_list.rs:36:12
[INFO] [stderr]    |
[INFO] [stderr] 35 | impl <T> LinkedList<T> {
[INFO] [stderr]    | ---------------------- associated items in this implementation
[INFO] [stderr] 36 |     pub fn new() -> Self {
[INFO] [stderr]    |            ^^^
[INFO] [stderr] ...
[INFO] [stderr] 40 |     pub fn append(&mut self, data: T) {
[INFO] [stderr]    |            ^^^^^^
[INFO] [stderr] ...
[INFO] [stderr] 53 |     pub fn get(&self, index: usize) -> Rc<RefCell<T>>{
[INFO] [stderr]    |            ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct `BytesStorage` is never constructed
[INFO] [stderr]  --> src/structures/bytes_storage.rs:3:12
[INFO] [stderr]   |
[INFO] [stderr] 3 | pub struct BytesStorage<'a> {
[INFO] [stderr]   |            ^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: multiple associated items are never used
[INFO] [stderr]   --> src/structures/bytes_storage.rs:9:12
[INFO] [stderr]    |
[INFO] [stderr]  8 | impl<'a> BytesStorage<'a> {
[INFO] [stderr]    | ------------------------- associated items in this implementation
[INFO] [stderr]  9 |     pub fn new(bytes: &'a mut Vec<u8>) -> Self {
[INFO] [stderr]    |            ^^^
[INFO] [stderr] ...
[INFO] [stderr] 14 |     pub fn set(&mut self, bytes: &'a mut Vec<u8>) {
[INFO] [stderr]    |            ^^^
[INFO] [stderr] ...
[INFO] [stderr] 20 |     pub fn get(&self) -> &'_ Vec<u8> {
[INFO] [stderr]    |            ^^^
[INFO] [stderr] ...
[INFO] [stderr] 24 |     pub fn len(&self) -> usize {
[INFO] [stderr]    |            ^^^
[INFO] [stderr] ...
[INFO] [stderr] 28 |     pub fn or(&mut self, other: &Self) {
[INFO] [stderr]    |            ^^
[INFO] [stderr] ...
[INFO] [stderr] 37 |     pub fn and(&mut self, other: &Self) {
[INFO] [stderr]    |            ^^^
[INFO] [stderr] ...
[INFO] [stderr] 46 |     pub fn xor(&mut self, other: &Self) {
[INFO] [stderr]    |            ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct `ExampleBox` is never constructed
[INFO] [stderr]  --> src/structures/example_box.rs:2:12
[INFO] [stderr]   |
[INFO] [stderr] 2 | pub struct ExampleBox<T: Display>(T);
[INFO] [stderr]   |            ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function `new` is never used
[INFO] [stderr]  --> src/structures/example_box.rs:5:12
[INFO] [stderr]   |
[INFO] [stderr] 4 | impl <T: Display> ExampleBox<T> {
[INFO] [stderr]   | ------------------------------- associated function in this implementation
[INFO] [stderr] 5 |     pub fn new(x: T) -> Self {
[INFO] [stderr]   |            ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: trait `Subscriber` is never used
[INFO] [stderr]  --> src/patterns/observer.rs:3:11
[INFO] [stderr]   |
[INFO] [stderr] 3 | pub trait Subscriber<T: Clone> {
[INFO] [stderr]   |           ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct `MessageSubscriber` is never constructed
[INFO] [stderr]  --> src/patterns/observer.rs:7:12
[INFO] [stderr]   |
[INFO] [stderr] 7 | pub struct MessageSubscriber {
[INFO] [stderr]   |            ^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function `new` is never used
[INFO] [stderr]   --> src/patterns/observer.rs:12:12
[INFO] [stderr]    |
[INFO] [stderr] 11 | impl MessageSubscriber {
[INFO] [stderr]    | ---------------------- associated function in this implementation
[INFO] [stderr] 12 |     pub fn new(message_placeholder: String) -> Self {
[INFO] [stderr]    |            ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: trait `Observer` is never used
[INFO] [stderr]   --> src/patterns/observer.rs:28:11
[INFO] [stderr]    |
[INFO] [stderr] 28 | pub trait Observer<'a, T: Clone> {
[INFO] [stderr]    |           ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct `MessageObserver` is never constructed
[INFO] [stderr]   --> src/patterns/observer.rs:33:12
[INFO] [stderr]    |
[INFO] [stderr] 33 | pub struct MessageObserver<'a> {
[INFO] [stderr]    |            ^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function `new` is never used
[INFO] [stderr]   --> src/patterns/observer.rs:38:12
[INFO] [stderr]    |
[INFO] [stderr] 37 | impl <'a> MessageObserver<'a> {
[INFO] [stderr]    | ----------------------------- associated function in this implementation
[INFO] [stderr] 38 |     pub fn new() -> Self {
[INFO] [stderr]    |            ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct `Cargo` is never constructed
[INFO] [stderr]  --> src/patterns/fabric.rs:3:12
[INFO] [stderr]   |
[INFO] [stderr] 3 | pub struct Cargo {
[INFO] [stderr]   |            ^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function `new` is never used
[INFO] [stderr]  --> src/patterns/fabric.rs:9:12
[INFO] [stderr]   |
[INFO] [stderr] 8 | impl Cargo {
[INFO] [stderr]   | ---------- associated function in this implementation
[INFO] [stderr] 9 |     pub fn new(name: String, weight_kg: u32) -> Self {
[INFO] [stderr]   |            ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: trait `Transport` is never used
[INFO] [stderr]   --> src/patterns/fabric.rs:14:11
[INFO] [stderr]    |
[INFO] [stderr] 14 | pub trait Transport {
[INFO] [stderr]    |           ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct `Taxi` is never constructed
[INFO] [stderr]   --> src/patterns/fabric.rs:18:12
[INFO] [stderr]    |
[INFO] [stderr] 18 | pub struct Taxi {
[INFO] [stderr]    |            ^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct `Bus` is never constructed
[INFO] [stderr]   --> src/patterns/fabric.rs:31:12
[INFO] [stderr]    |
[INFO] [stderr] 31 | pub struct Bus {
[INFO] [stderr]    |            ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct `TransportFactory` is never constructed
[INFO] [stderr]   --> src/patterns/fabric.rs:44:12
[INFO] [stderr]    |
[INFO] [stderr] 44 | pub struct TransportFactory {}
[INFO] [stderr]    |            ^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function `create` is never used
[INFO] [stderr]   --> src/patterns/fabric.rs:47:12
[INFO] [stderr]    |
[INFO] [stderr] 46 | impl TransportFactory {
[INFO] [stderr]    | --------------------- associated function in this implementation
[INFO] [stderr] 47 |     pub fn create(
[INFO] [stderr]    |            ^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct `BadTransportTypeError` is never constructed
[INFO] [stderr]   --> src/patterns/fabric.rs:60:12
[INFO] [stderr]    |
[INFO] [stderr] 60 | pub struct BadTransportTypeError {}
[INFO] [stderr]    |            ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: enum `List` is never used
[INFO] [stderr]  --> src/stdlib/pointers.rs:3:10
[INFO] [stderr]   |
[INFO] [stderr] 3 | pub enum List {
[INFO] [stderr]   |          ^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `some_action_with_value` is never used
[INFO] [stderr]  --> src/stdlib/pointers.rs:9:4
[INFO] [stderr]   |
[INFO] [stderr] 9 | fn some_action_with_value(value: &i32) {
[INFO] [stderr]   |    ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `iterate_list` is never used
[INFO] [stderr]   --> src/stdlib/pointers.rs:13:4
[INFO] [stderr]    |
[INFO] [stderr] 13 | fn iterate_list(current: Box<List>) {
[INFO] [stderr]    |    ^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `simple_demo_box` is never used
[INFO] [stderr]   --> src/stdlib/pointers.rs:25:8
[INFO] [stderr]    |
[INFO] [stderr] 25 | pub fn simple_demo_box() {
[INFO] [stderr]    |        ^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: enum `Tree` is never used
[INFO] [stderr]   --> src/stdlib/pointers.rs:31:10
[INFO] [stderr]    |
[INFO] [stderr] 31 | pub enum Tree {
[INFO] [stderr]    |          ^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `iterate_tree` is never used
[INFO] [stderr]   --> src/stdlib/pointers.rs:36:4
[INFO] [stderr]    |
[INFO] [stderr] 36 | fn iterate_tree(root: Rc<Tree>) {
[INFO] [stderr]    |    ^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `simple_demo_rc` is never used
[INFO] [stderr]   --> src/stdlib/pointers.rs:48:8
[INFO] [stderr]    |
[INFO] [stderr] 48 | pub fn simple_demo_rc() {
[INFO] [stderr]    |        ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: trait `Messenger` is never used
[INFO] [stderr]  --> src/stdlib/ref_cells.rs:3:11
[INFO] [stderr]   |
[INFO] [stderr] 3 | pub trait Messenger {
[INFO] [stderr]   |           ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct `LimitTracker` is never constructed
[INFO] [stderr]  --> src/stdlib/ref_cells.rs:7:12
[INFO] [stderr]   |
[INFO] [stderr] 7 | pub struct LimitTracker<'a, T: Messenger> {
[INFO] [stderr]   |            ^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated items `new` and `set_value` are never used
[INFO] [stderr]   --> src/stdlib/ref_cells.rs:14:12
[INFO] [stderr]    |
[INFO] [stderr] 13 | impl <'a, T> LimitTracker<'a, T>  where T: Messenger {
[INFO] [stderr]    | ---------------------------------------------------- associated items in this implementation
[INFO] [stderr] 14 |     pub fn new(messenger: &'a T, max: usize) -> LimitTracker<'a, T> {
[INFO] [stderr]    |            ^^^
[INFO] [stderr] ...
[INFO] [stderr] 18 |     pub fn set_value(&mut self, value: usize) {
[INFO] [stderr]    |            ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct `AccumulativeMessenger` is never constructed
[INFO] [stderr]   --> src/stdlib/ref_cells.rs:29:8
[INFO] [stderr]    |
[INFO] [stderr] 29 | struct AccumulativeMessenger {
[INFO] [stderr]    |        ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function `new` is never used
[INFO] [stderr]   --> src/stdlib/ref_cells.rs:34:12
[INFO] [stderr]    |
[INFO] [stderr] 33 | impl  AccumulativeMessenger {
[INFO] [stderr]    | --------------------------- associated function in this implementation
[INFO] [stderr] 34 |     pub fn new() -> Self {
[INFO] [stderr]    |            ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: function `ref_cell_demo` is never used
[INFO] [stderr]   --> src/stdlib/ref_cells.rs:45:8
[INFO] [stderr]    |
[INFO] [stderr] 45 | pub fn ref_cell_demo() {
[INFO] [stderr]    |        ^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct `Tree` is never constructed
[INFO] [stderr]  --> src/stdlib/rc_refcell.rs:3:12
[INFO] [stderr]   |
[INFO] [stderr] 3 | pub struct Tree {
[INFO] [stderr]   |            ^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct `AlreadyInTreeError` is never constructed
[INFO] [stderr]  --> src/stdlib/rc_refcell.rs:9:12
[INFO] [stderr]   |
[INFO] [stderr] 9 | pub struct AlreadyInTreeError {}
[INFO] [stderr]   |            ^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated items `new`, `push`, and `traverse` are never used
[INFO] [stderr]   --> src/stdlib/rc_refcell.rs:12:12
[INFO] [stderr]    |
[INFO] [stderr] 11 | impl Tree {
[INFO] [stderr]    | --------- associated items in this implementation
[INFO] [stderr] 12 |     pub fn new(data: i32) -> Self {
[INFO] [stderr]    |            ^^^
[INFO] [stderr] ...
[INFO] [stderr] 16 |     pub fn push(&self, data: i32) -> Result<i32, AlreadyInTreeError> {
[INFO] [stderr]    |            ^^^^
[INFO] [stderr] ...
[INFO] [stderr] 39 |     pub fn traverse(&self, apply_to_node_fn: fn(node: i32)) {
[INFO] [stderr]    |            ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stderr]   --> src/structures/container.rs:44:17
[INFO] [stderr]    |
[INFO] [stderr] 44 |     pub fn iter(&self) -> Iter<T> {
[INFO] [stderr]    |                 ^^^^^     ^^^^^^^ the same lifetime is hidden here
[INFO] [stderr]    |                 |
[INFO] [stderr]    |                 the lifetime is elided here
[INFO] [stderr]    |
[INFO] [stderr]    = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stderr]    = note: `#[warn(mismatched_lifetime_syntaxes)]` on by default
[INFO] [stderr] help: use `'_` for type paths
[INFO] [stderr]    |
[INFO] [stderr] 44 |     pub fn iter(&self) -> Iter<'_, T> {
[INFO] [stderr]    |                                +++
[INFO] [stderr] 
[INFO] [stderr] warning: unused `Result` that must be used
[INFO] [stderr]   --> src/stdlib/rc_refcell.rs:20:17
[INFO] [stderr]    |
[INFO] [stderr] 20 |                 right_node.push(data);
[INFO] [stderr]    |                 ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr]    = note: `#[warn(unused_must_use)]` (part of `#[warn(unused)]`) on by default
[INFO] [stderr] help: use `let _ = ...` to ignore the resulting value
[INFO] [stderr]    |
[INFO] [stderr] 20 |                 let _ = right_node.push(data);
[INFO] [stderr]    |                 +++++++
[INFO] [stderr] 
[INFO] [stderr] warning: unused `Result` that must be used
[INFO] [stderr]   --> src/stdlib/rc_refcell.rs:28:17
[INFO] [stderr]    |
[INFO] [stderr] 28 |                 left_node.push(data);
[INFO] [stderr]    |                 ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr] help: use `let _ = ...` to ignore the resulting value
[INFO] [stderr]    |
[INFO] [stderr] 28 |                 let _ = left_node.push(data);
[INFO] [stderr]    |                 +++++++
[INFO] [stderr] 
[INFO] [stderr] warning: unused `Result` that must be used
[INFO] [stderr]   --> src/stdlib/rc_refcell.rs:34:13
[INFO] [stderr]    |
[INFO] [stderr] 34 |             Err::<i32, AlreadyInTreeError>(AlreadyInTreeError{});
[INFO] [stderr]    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr] help: use `let _ = ...` to ignore the resulting value
[INFO] [stderr]    |
[INFO] [stderr] 34 |             let _ = Err::<i32, AlreadyInTreeError>(AlreadyInTreeError{});
[INFO] [stderr]    |             +++++++
[INFO] [stderr] 
[INFO] [stderr] warning: `rust-excercises` (bin "rust-excercises" test) generated 79 warnings (run `cargo fix --bin "rust-excercises" -p rust-excercises --tests` to apply 4 suggestions)
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.03s
[INFO] [stderr]      Running unittests src/main.rs (/opt/rustwide/target/debug/deps/rust_excercises-db7c5064da081545)
[INFO] [stdout] 
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "1ced85b770812ef6699f9cc413db734c480da47abf93239eed0a83a98e4ca56c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1ced85b770812ef6699f9cc413db734c480da47abf93239eed0a83a98e4ca56c", kill_on_drop: false }`
[INFO] [stdout] 1ced85b770812ef6699f9cc413db734c480da47abf93239eed0a83a98e4ca56c
