release: 4.2.0

Co-authored-by: Volodymyr Patuta <6977238-fiplox@users.noreply.gitlab.com>

.all-contributorsrc

@@ -454,11 +454,194 @@
         "code",
         "content"
       ]
+    },
+    {
+      "login": "uce",
+      "name": "Ufuk Celebi",
+      "avatar_url": "https://avatars3.githubusercontent.com/u/1756620?v=4",
+      "profile": "https://github.com/uce",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "lebedevsergey",
+      "name": "lebedevsergey",
+      "avatar_url": "https://avatars2.githubusercontent.com/u/7325764?v=4",
+      "profile": "https://github.com/lebedevsergey",
+      "contributions": [
+        "doc"
+      ]
+    },
+    {
+      "login": "avrong",
+      "name": "Aleksei Trifonov",
+      "avatar_url": "https://avatars2.githubusercontent.com/u/6342851?v=4",
+      "profile": "https://github.com/avrong",
+      "contributions": [
+        "content"
+      ]
+    },
+    {
+      "login": "Darrenmeehan",
+      "name": "Darren Meehan",
+      "avatar_url": "https://avatars2.githubusercontent.com/u/411136?v=4",
+      "profile": "https://drn.ie",
+      "contributions": [
+        "content"
+      ]
+    },
+    {
+      "login": "jihchi",
+      "name": "Jihchi Lee",
+      "avatar_url": "https://avatars1.githubusercontent.com/u/87983?v=4",
+      "profile": "https://github.com/jihchi",
+      "contributions": [
+        "content"
+      ]
+    },
+    {
+      "login": "bertonha",
+      "name": "Christofer Bertonha",
+      "avatar_url": "https://avatars3.githubusercontent.com/u/1225902?v=4",
+      "profile": "https://github.com/bertonha",
+      "contributions": [
+        "content"
+      ]
+    },
+    {
+      "login": "apatniv",
+      "name": "Vivek Bharath Akupatni",
+      "avatar_url": "https://avatars2.githubusercontent.com/u/22565917?v=4",
+      "profile": "https://github.com/apatniv",
+      "contributions": [
+        "code",
+        "test"
+      ]
+    },
+    {
+      "login": "DiD92",
+      "name": "Dídac Sementé Fernández",
+      "avatar_url": "https://avatars3.githubusercontent.com/u/6002416?v=4",
+      "profile": "https://github.com/DiD92",
+      "contributions": [
+        "code",
+        "content"
+      ]
+    },
+    {
+      "login": "wrobstory",
+      "name": "Rob Story",
+      "avatar_url": "https://avatars3.githubusercontent.com/u/2601457?v=4",
+      "profile": "https://github.com/wrobstory",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "siobhanjacobson",
+      "name": "Siobhan Jacobson",
+      "avatar_url": "https://avatars2.githubusercontent.com/u/28983835?v=4",
+      "profile": "https://github.com/siobhanjacobson",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "EvanCarroll",
+      "name": "Evan Carroll",
+      "avatar_url": "https://avatars2.githubusercontent.com/u/19922?v=4",
+      "profile": "https://www.linkedin.com/in/evancarroll/",
+      "contributions": [
+        "content"
+      ]
+    },
+    {
+      "login": "jmahmood",
+      "name": "Jawaad Mahmood",
+      "avatar_url": "https://avatars3.githubusercontent.com/u/95606?v=4",
+      "profile": "http://www.jawaadmahmood.com",
+      "contributions": [
+        "content"
+      ]
+    },
+    {
+      "login": "GaurangTandon",
+      "name": "Gaurang Tandon",
+      "avatar_url": "https://avatars1.githubusercontent.com/u/6308683?v=4",
+      "profile": "https://github.com/GaurangTandon",
+      "contributions": [
+        "content"
+      ]
+    },
+    {
+      "login": "dev-cyprium",
+      "name": "Stefan Kupresak",
+      "avatar_url": "https://avatars1.githubusercontent.com/u/6002628?v=4",
+      "profile": "https://github.com/dev-cyprium",
+      "contributions": [
+        "content"
+      ]
+    },
+    {
+      "login": "greg-el",
+      "name": "Greg Leonard",
+      "avatar_url": "https://avatars3.githubusercontent.com/u/45019882?v=4",
+      "profile": "https://github.com/greg-el",
+      "contributions": [
+        "content"
+      ]
+    },
+    {
+      "login": "ryanpcmcquen",
+      "name": "Ryan McQuen",
+      "avatar_url": "https://avatars3.githubusercontent.com/u/772937?v=4",
+      "profile": "https://ryanpcmcquen.org",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "AnnikaCodes",
+      "name": "Annika",
+      "avatar_url": "https://avatars3.githubusercontent.com/u/56906084?v=4",
+      "profile": "https://github.com/AnnikaCodes",
+      "contributions": [
+        "review"
+      ]
+    },
+    {
+      "login": "darnuria",
+      "name": "Axel Viala",
+      "avatar_url": "https://avatars1.githubusercontent.com/u/2827553?v=4",
+      "profile": "https://darnuria.eu",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "sazid",
+      "name": "Mohammed Sazid Al Rashid",
+      "avatar_url": "https://avatars1.githubusercontent.com/u/2370167?v=4",
+      "profile": "https://sazid.github.io",
+      "contributions": [
+        "content",
+        "code"
+      ]
+    },
+    {
+      "login": "seeplusplus",
+      "name": "Caleb Webber",
+      "avatar_url": "https://avatars1.githubusercontent.com/u/17479099?v=4",
+      "profile": "https://codingthemsoftly.com",
+      "contributions": [
+        "maintenance"
+      ]
     }
   ],
   "contributorsPerLine": 8,
   "projectName": "rustlings",
-  "projectOwner": "fmoko",
+  "projectOwner": "rust-lang",
   "repoType": "github",
   "repoHost": "https://github.com",
   "skipCi": true

.gitignore

@@ -6,3 +6,4 @@ target/
 exercises/clippy/Cargo.toml
 exercises/clippy/Cargo.lock
 .idea
+.vscode

.gitpod.yml

@@ -0,0 +1,7 @@
+tasks:
+  - init: /workspace/rustlings/install.sh
+    command: /workspace/.cargo/bin/rustlings watch
+
+vscode:
+  extensions:
+    - rust-lang.rust@0.7.8:CvNqMTgDdt3UXt+6BCDTVg==

.replit

@@ -0,0 +1,2 @@
+language = "rust"
+run = "[ -x ~/.cargo/bin/rustlings ] && ~/.cargo/bin/rustlings watch || ./install.sh"

CHANGELOG.md

@@ -1,10 +1,54 @@
+<a name="4.2.0"></a>
+## 4.2.0 (2020-11-07)
+
+#### Features
+
+*   Add HashMap exercises ([633c00cf](https://github.com/rust-lang/rustlings/commit/633c00cf8071e1e82959a3010452a32f34f29fc9))
+*   Add Vec exercises ([0c12fa31](https://github.com/rust-lang/rustlings/commit/0c12fa31c57c03c6287458a0a8aca7afd057baf6))
+* **primitive_types6:**  Add a test (#548) ([2b1fb2b7](https://github.com/rust-lang/rustlings/commit/2b1fb2b739bf9ad8d6b7b12af25fee173011bfc4))
+* **try_from_into:**  Add tests (#571) ([95ccd926](https://github.com/rust-lang/rustlings/commit/95ccd92616ae79ba287cce221101e0bbe4f68cdc))
+
+#### Bug Fixes
+
+*   log error output when inotify limit is exceeded ([d61b4e5a](https://github.com/rust-lang/rustlings/commit/d61b4e5a13b44d72d004082f523fa1b6b24c1aca))
+*   more unique temp_file ([5643ef05](https://github.com/rust-lang/rustlings/commit/5643ef05bc81e4a840e9456f4406a769abbe1392))
+* **installation:**  Update the MinRustVersion ([21bfb2d4](https://github.com/rust-lang/rustlings/commit/21bfb2d4777429c87d8d3b5fbf0ce66006dcd034))
+* **iterators2:**  Update description (#578) ([197d3a3d](https://github.com/rust-lang/rustlings/commit/197d3a3d8961b2465579218a6749b2b2cefa8ddd))
+* **primitive_types6:**
+  *  remove 'unused doc comment' warning ([472d8592](https://github.com/rust-lang/rustlings/commit/472d8592d65c8275332a20dfc269e7ac0d41bc88))
+  *  missing comma in test ([4fb230da](https://github.com/rust-lang/rustlings/commit/4fb230daf1251444fcf29e085cee222a91f8a37e))
+* **quiz3:**  Second test is for odd numbers, not even. (#553) ([18e0bfef](https://github.com/rust-lang/rustlings/commit/18e0bfef1de53071e353ba1ec5837002ff7290e6))
+
+<a name="4.1.0"></a>
+## 4.1.0 (2020-10-05)
+
+#### Bug Fixes
+
+*   Update rustlings version in Cargo.lock ([1cc40bc9](https://github.com/rust-lang/rustlings/commit/1cc40bc9ce95c23d56f6d91fa1c4deb646231fef))
+* **arc1:**  index mod should equal thread count ([b4062ef6](https://github.com/rust-lang/rustlings/commit/b4062ef6993e80dac107c4093ea85166ad3ee0fa))
+* **enums3:**  Update Message::ChangeColor to take a tuple. (#457) ([4b6540c7](https://github.com/rust-lang/rustlings/commit/4b6540c71adabad647de8a09e57295e7c7c7d794))
+* **exercises:**  adding question mark to quiz2 ([101072ab](https://github.com/rust-lang/rustlings/commit/101072ab9f8c80b40b8b88cb06cbe38aca2481c5))
+* **generics3:**  clarify grade change ([47f7672c](https://github.com/rust-lang/rustlings/commit/47f7672c0307732056e7426e81d351f0dd7e22e5))
+* **structs3:**  Small adjustment of variable name ([114b54cb](https://github.com/rust-lang/rustlings/commit/114b54cbdb977234b39e5f180d937c14c78bb8b2))
+* **using_as:**  Add test so that proper type is returned. (#512) ([3286c5ec](https://github.com/rust-lang/rustlings/commit/3286c5ec19ea5fb7ded81d047da5f8594108a490))
+
+#### Features
+
+*   Added iterators1.rs exercise ([9642f5a3](https://github.com/rust-lang/rustlings/commit/9642f5a3f686270a4f8f6ba969919ddbbc4f7fdd))
+*   Add ability to run rustlings on repl.it (#471) ([8f7b5bd0](https://github.com/rust-lang/rustlings/commit/8f7b5bd00eb83542b959830ef55192d2d76db90a))
+*   Add gitpod support (#473) ([4821a8be](https://github.com/rust-lang/rustlings/commit/4821a8be94af4f669042a06ab917934cfacd032f))
+*   Remind the user of the hint option (#425) ([816b1f5e](https://github.com/rust-lang/rustlings/commit/816b1f5e85d6cc6e72673813a85d0ada2a8f84af))
+*   Remind the user of the hint option (#425) ([9f61db5d](https://github.com/rust-lang/rustlings/commit/9f61db5dbe38538cf06571fcdd5f806e7901e83a))
+* **cli:**  Added 'cls' command to 'watch' mode (#474) ([4f2468e1](https://github.com/rust-lang/rustlings/commit/4f2468e14f574a93a2e9b688367b5752ed96ae7b))
+* **try_from_into:**  Add insufficient length test (#469) ([523d18b8](https://github.com/rust-lang/rustlings/commit/523d18b873a319f7c09262f44bd40e2fab1830e5))
+
 <a name="4.0.0"></a>
 ## 4.0.0 (2020-07-08)
 
 #### Breaking Changes
 
-*   Add a --nocapture option to display test harnesses' outputs ([8ad5f9bf](https://github.com/rust-lang/rustlings/commit/8ad5f9bf531a4848b1104b7b389a20171624c82f)
-*   Rename test to quiz, fixes #244 ([010a0456](https://github.com/rust-lang/rustlings/commit/010a04569282149cea7f7a76fc4d7f4c9f0f08dd)
+*   Add a --nocapture option to display test harnesses' outputs ([8ad5f9bf](https://github.com/rust-lang/rustlings/commit/8ad5f9bf531a4848b1104b7b389a20171624c82f))
+*   Rename test to quiz, fixes #244 ([010a0456](https://github.com/rust-lang/rustlings/commit/010a04569282149cea7f7a76fc4d7f4c9f0f08dd))
 
 #### Features
 
@@ -83,14 +127,14 @@
 *   Update deps to version compatable with aarch64-pc-windows (#263) ([19a93428](https://github.com/rust-lang/rustlings/commit/19a93428b3c73d994292671f829bdc8e5b7b3401))
 * **docs:**
   * Added a necessary step to Windows installation process (#242) ([3906efcd](https://github.com/rust-lang/rustlings/commit/3906efcd52a004047b460ed548037093de3f523f))
-  * Fixed mangled sentence from book; edited for clarity (#266) ([ade52ff](https://github.com/rust-lang/rustlings/commit/ade52ffb739987287ddd5705944c8777705faed9)) 
+  * Fixed mangled sentence from book; edited for clarity (#266) ([ade52ff](https://github.com/rust-lang/rustlings/commit/ade52ffb739987287ddd5705944c8777705faed9))
   * Updated iterators readme to account for iterators4 exercise (#273) ([bec8e3a](https://github.com/rust-lang/rustlings/commit/bec8e3a644cbd88db1c73ea5f1d8a364f4a34016))
 * **installation:**  make fatal errors more obvious (#272) ([17d0951e](https://github.com/rust-lang/rustlings/commit/17d0951e66fda8e11b204d5c4c41a0d5e22e78f7))
 * **iterators2:**
   *  Remove reference to missing iterators2.rs (#245) ([419f7797](https://github.com/rust-lang/rustlings/commit/419f7797f294e4ce6a2b883199731b5bde77d262))
 * **as_ref_mut:** Enable a test and improve per clippy's suggestion (#256) ([dfdf809](https://github.com/rust-lang/rustlings/commit/dfdf8093ebbd4145864995627b812780de52f902))
 * **tests1:**
-  * Change test command ([fe10e06c](https://github.com/rust-lang/rustlings/commit/fe10e06c3733ddb4a21e90d09bf79bfe618e97ce) 
+  * Change test command ([fe10e06c](https://github.com/rust-lang/rustlings/commit/fe10e06c3733ddb4a21e90d09bf79bfe618e97ce)
   * Correct test command in tests1.rs comment (#263) ([39fa7ae](https://github.com/rust-lang/rustlings/commit/39fa7ae8b70ad468da49b06f11b2383135a63bcf))
 
 #### Features

Cargo.lock

@@ -592,7 +592,7 @@ dependencies = [
 
 [[package]]
 name = "rustlings"
-version = "3.0.0"
+version = "4.2.0"
 dependencies = [
  "assert_cmd 0.11.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "clap 2.33.0 (registry+https://github.com/rust-lang/crates.io-index)",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "rustlings"
-version = "4.0.0"
+version = "4.2.0"
 authors = ["Marisa <mokou@posteo.de>", "Carol (Nichols || Goulding) <carol.nichols@gmail.com>"]
 edition = "2018"
 

README.md

@@ -1,6 +1,6 @@
 ![crab pet](https://i.imgur.com/LbZJgmm.gif)
 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
-[![All Contributors](https://img.shields.io/badge/all_contributors-48-orange.svg?style=flat-square)](#contributors-)
+[![All Contributors](https://img.shields.io/badge/all_contributors-68-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
 # rustlings 🦀❤️ [![Build status](https://badge.buildkite.com/7af93d81dc522c67a1ec8e33ff5705861b1cb36360b774807f.svg)](https://buildkite.com/mokou/rustlings)
@@ -9,7 +9,7 @@ Greetings and welcome to `rustlings`. This project contains small exercises to g
 
 _...looking for the old, web-based version of Rustlings? Try [here](https://github.com/rust-lang/rustlings/tree/rustlings-1)_
 
-Alternatively, for a first-time Rust learner, there's several other resources:
+Alternatively, for a first-time Rust learner, there are several other resources:
 
 - [The Book](https://doc.rust-lang.org/book/index.html) - The most comprehensive resource for learning Rust, but a bit theoretical sometimes. You will be using this along with Rustlings!
 - [Rust By Example](https://doc.rust-lang.org/rust-by-example/index.html) - Learn Rust by solving little exercises! It's almost like `rustlings`, but online
@@ -48,6 +48,12 @@ Start-BitsTransfer -Source https://git.io/rustlings-win -Destination $env:TMP/in
 
 To install Rustlings. Same as on MacOS/Linux, you will have access to the `rustlings` command after it.
 
+## Browser:
+
+[Run on Repl.it](https://repl.it/github/rust-lang/rustlings)
+
+[Open in Gitpod](https://gitpod.io/#https://github.com/rust-lang/rustlings)
+
 ## Manually
 
 Basically: Clone the repository, checkout to the latest tag, run `cargo install`.
@@ -55,7 +61,7 @@ Basically: Clone the repository, checkout to the latest tag, run `cargo install`
 ```bash
 git clone https://github.com/rust-lang/rustlings
 cd rustlings
-git checkout tags/4.0.0 # or whatever the latest version is (find out at https://github.com/rust-lang/rustlings/releases/latest)
+git checkout tags/4.2.0 # or whatever the latest version is (find out at https://github.com/rust-lang/rustlings/releases/latest)
 cargo install --force --path .
 ```
 
@@ -70,7 +76,7 @@ Then, same as above, run `rustlings` to get started.
 
 The exercises are sorted by topic and can be found in the subdirectory `rustlings/exercises/<topic>`. For every topic there is an additional README file with some resources to get you started on the topic. We really recommend that you have a look at them before you start.
 
-The task is simple. Most exercises contain an error that keep it from compiling, and it's up to you to fix it! Some exercises are also run as tests, but rustlings handles them all the same. To run the exercises in the recommended order, execute:
+The task is simple. Most exercises contain an error that keeps them from compiling, and it's up to you to fix it! Some exercises are also run as tests, but rustlings handles them all the same. To run the exercises in the recommended order, execute:
 
 ```bash
 rustlings watch
@@ -101,6 +107,17 @@ rustlings hint myExercise1
 
 After every couple of sections, there will be a quiz that'll test your knowledge on a bunch of sections at once. These quizzes are found in `exercises/quizN.rs`.
 
+## Continuing On
+
+Once you've completed Rustlings, put your new knowledge to good use! Continue practicing your Rust skills by building your own projects, contributing to Rustlings, or finding other open-source projects to contribute to.
+
+If you'd like to uninstall Rustlings, you can do so by invoking cargo and removing the rustlings directory:
+
+```bash
+cargo uninstall rustlings
+rm -r rustlings/ # or on Windows: rmdir /s rustlings
+```
+
 ## Completion
 
 Rustlings isn't done; there are a couple of sections that are very experimental and don't have proper documentation. These include:
@@ -132,64 +149,90 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
 <!-- markdownlint-disable -->
 <table>
   <tr>
-    <td align="center"><a href="http://carol-nichols.com"><img src="https://avatars2.githubusercontent.com/u/193874?v=4" width="100px;" alt=""/><br /><sub><b>Carol (Nichols &#124;&#124; Goulding)</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=carols10cents" title="Code">💻</a> <a href="#content-carols10cents" title="Content">🖋</a></td>
-    <td align="center"><a href="https://twitter.com/QuietMisdreavus"><img src="https://avatars2.githubusercontent.com/u/5217170?v=4" width="100px;" alt=""/><br /><sub><b>QuietMisdreavus</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=QuietMisdreavus" title="Code">💻</a> <a href="#content-QuietMisdreavus" title="Content">🖋</a></td>
+    <td align="center"><a href="http://carol-nichols.com"><img src="https://avatars2.githubusercontent.com/u/193874?v=4" width="100px;" alt=""/><br /><sub><b>Carol (Nichols &#124;&#124; Goulding)</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=carols10cents" title="Code">💻</a> <a href="#content-carols10cents" title="Content">🖋</a></td>
+    <td align="center"><a href="https://twitter.com/QuietMisdreavus"><img src="https://avatars2.githubusercontent.com/u/5217170?v=4" width="100px;" alt=""/><br /><sub><b>QuietMisdreavus</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=QuietMisdreavus" title="Code">💻</a> <a href="#content-QuietMisdreavus" title="Content">🖋</a></td>
     <td align="center"><a href="https://github.com/robertlugg"><img src="https://avatars0.githubusercontent.com/u/6054540?v=4" width="100px;" alt=""/><br /><sub><b>Robert M Lugg</b></sub></a><br /><a href="#content-robertlugg" title="Content">🖋</a></td>
-    <td align="center"><a href="https://hynek.me/about/"><img src="https://avatars3.githubusercontent.com/u/41240?v=4" width="100px;" alt=""/><br /><sub><b>Hynek Schlawack</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=hynek" title="Code">💻</a></td>
-    <td align="center"><a href="https://spacekookie.de"><img src="https://avatars0.githubusercontent.com/u/7669898?v=4" width="100px;" alt=""/><br /><sub><b>Katharina Fey</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=spacekookie" title="Code">💻</a></td>
-    <td align="center"><a href="https://github.com/lukabavdaz"><img src="https://avatars0.githubusercontent.com/u/9624558?v=4" width="100px;" alt=""/><br /><sub><b>lukabavdaz</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=lukabavdaz" title="Code">💻</a> <a href="#content-lukabavdaz" title="Content">🖋</a></td>
-    <td align="center"><a href="http://vestera.as"><img src="https://avatars2.githubusercontent.com/u/4187449?v=4" width="100px;" alt=""/><br /><sub><b>Erik Vesteraas</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=evestera" title="Code">💻</a></td>
-    <td align="center"><a href="https://github.com/Delet0r"><img src="https://avatars1.githubusercontent.com/u/23195618?v=4" width="100px;" alt=""/><br /><sub><b>delet0r</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=Delet0r" title="Code">💻</a></td>
+    <td align="center"><a href="https://hynek.me/about/"><img src="https://avatars3.githubusercontent.com/u/41240?v=4" width="100px;" alt=""/><br /><sub><b>Hynek Schlawack</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=hynek" title="Code">💻</a></td>
+    <td align="center"><a href="https://spacekookie.de"><img src="https://avatars0.githubusercontent.com/u/7669898?v=4" width="100px;" alt=""/><br /><sub><b>Katharina Fey</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=spacekookie" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/lukabavdaz"><img src="https://avatars0.githubusercontent.com/u/9624558?v=4" width="100px;" alt=""/><br /><sub><b>lukabavdaz</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=lukabavdaz" title="Code">💻</a> <a href="#content-lukabavdaz" title="Content">🖋</a></td>
+    <td align="center"><a href="http://vestera.as"><img src="https://avatars2.githubusercontent.com/u/4187449?v=4" width="100px;" alt=""/><br /><sub><b>Erik Vesteraas</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=evestera" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/Delet0r"><img src="https://avatars1.githubusercontent.com/u/23195618?v=4" width="100px;" alt=""/><br /><sub><b>delet0r</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=Delet0r" title="Code">💻</a></td>
   </tr>
   <tr>
-    <td align="center"><a href="http://phinary.ca"><img src="https://avatars1.githubusercontent.com/u/10522375?v=4" width="100px;" alt=""/><br /><sub><b>Shaun Bennett</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=shaunbennett" title="Code">💻</a></td>
-    <td align="center"><a href="https://github.com/abagshaw"><img src="https://avatars2.githubusercontent.com/u/8594541?v=4" width="100px;" alt=""/><br /><sub><b>Andrew Bagshaw</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=abagshaw" title="Code">💻</a></td>
-    <td align="center"><a href="https://ai6ua.net/"><img src="https://avatars2.githubusercontent.com/u/175578?v=4" width="100px;" alt=""/><br /><sub><b>Kyle Isom</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=kisom" title="Code">💻</a></td>
-    <td align="center"><a href="https://github.com/ColinPitrat"><img src="https://avatars3.githubusercontent.com/u/1541863?v=4" width="100px;" alt=""/><br /><sub><b>Colin Pitrat</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=ColinPitrat" title="Code">💻</a></td>
-    <td align="center"><a href="https://zacanger.com"><img src="https://avatars3.githubusercontent.com/u/12520493?v=4" width="100px;" alt=""/><br /><sub><b>Zac Anger</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=zacanger" title="Code">💻</a></td>
-    <td align="center"><a href="https://github.com/mgeier"><img src="https://avatars1.githubusercontent.com/u/705404?v=4" width="100px;" alt=""/><br /><sub><b>Matthias Geier</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=mgeier" title="Code">💻</a></td>
-    <td align="center"><a href="https://github.com/cjpearce"><img src="https://avatars1.githubusercontent.com/u/3453268?v=4" width="100px;" alt=""/><br /><sub><b>Chris Pearce</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=cjpearce" title="Code">💻</a></td>
-    <td align="center"><a href="https://yvan-sraka.github.io"><img src="https://avatars2.githubusercontent.com/u/705213?v=4" width="100px;" alt=""/><br /><sub><b>Yvan Sraka</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=yvan-sraka" title="Code">💻</a></td>
+    <td align="center"><a href="http://phinary.ca"><img src="https://avatars1.githubusercontent.com/u/10522375?v=4" width="100px;" alt=""/><br /><sub><b>Shaun Bennett</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=shaunbennett" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/abagshaw"><img src="https://avatars2.githubusercontent.com/u/8594541?v=4" width="100px;" alt=""/><br /><sub><b>Andrew Bagshaw</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=abagshaw" title="Code">💻</a></td>
+    <td align="center"><a href="https://ai6ua.net/"><img src="https://avatars2.githubusercontent.com/u/175578?v=4" width="100px;" alt=""/><br /><sub><b>Kyle Isom</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=kisom" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/ColinPitrat"><img src="https://avatars3.githubusercontent.com/u/1541863?v=4" width="100px;" alt=""/><br /><sub><b>Colin Pitrat</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=ColinPitrat" title="Code">💻</a></td>
+    <td align="center"><a href="https://zacanger.com"><img src="https://avatars3.githubusercontent.com/u/12520493?v=4" width="100px;" alt=""/><br /><sub><b>Zac Anger</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=zacanger" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/mgeier"><img src="https://avatars1.githubusercontent.com/u/705404?v=4" width="100px;" alt=""/><br /><sub><b>Matthias Geier</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=mgeier" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/cjpearce"><img src="https://avatars1.githubusercontent.com/u/3453268?v=4" width="100px;" alt=""/><br /><sub><b>Chris Pearce</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=cjpearce" title="Code">💻</a></td>
+    <td align="center"><a href="https://yvan-sraka.github.io"><img src="https://avatars2.githubusercontent.com/u/705213?v=4" width="100px;" alt=""/><br /><sub><b>Yvan Sraka</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=yvan-sraka" title="Code">💻</a></td>
   </tr>
   <tr>
-    <td align="center"><a href="https://github.com/dendi239"><img src="https://avatars3.githubusercontent.com/u/16478650?v=4" width="100px;" alt=""/><br /><sub><b>Denys Smirnov</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=dendi239" title="Code">💻</a></td>
-    <td align="center"><a href="https://github.com/eddyp"><img src="https://avatars2.githubusercontent.com/u/123772?v=4" width="100px;" alt=""/><br /><sub><b>eddyp</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=eddyp" title="Code">💻</a></td>
-    <td align="center"><a href="http://about.me/BrianKung"><img src="https://avatars1.githubusercontent.com/u/2836167?v=4" width="100px;" alt=""/><br /><sub><b>Brian Kung</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=briankung" title="Code">💻</a> <a href="#content-briankung" title="Content">🖋</a></td>
-    <td align="center"><a href="https://rcousineau.gitlab.io"><img src="https://avatars3.githubusercontent.com/u/281039?v=4" width="100px;" alt=""/><br /><sub><b>Russell</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=miller-time" title="Code">💻</a></td>
-    <td align="center"><a href="http://danwilhelm.com"><img src="https://avatars3.githubusercontent.com/u/6137185?v=4" width="100px;" alt=""/><br /><sub><b>Dan Wilhelm</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=danwilhelm" title="Documentation">📖</a></td>
-    <td align="center"><a href="https://github.com/Jesse-Cameron"><img src="https://avatars3.githubusercontent.com/u/3723654?v=4" width="100px;" alt=""/><br /><sub><b>Jesse</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=Jesse-Cameron" title="Code">💻</a> <a href="#content-Jesse-Cameron" title="Content">🖋</a></td>
-    <td align="center"><a href="https://github.com/MrFroop"><img src="https://avatars3.githubusercontent.com/u/196700?v=4" width="100px;" alt=""/><br /><sub><b>Fredrik Jambrén</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=MrFroop" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/dendi239"><img src="https://avatars3.githubusercontent.com/u/16478650?v=4" width="100px;" alt=""/><br /><sub><b>Denys Smirnov</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=dendi239" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/eddyp"><img src="https://avatars2.githubusercontent.com/u/123772?v=4" width="100px;" alt=""/><br /><sub><b>eddyp</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=eddyp" title="Code">💻</a></td>
+    <td align="center"><a href="http://about.me/BrianKung"><img src="https://avatars1.githubusercontent.com/u/2836167?v=4" width="100px;" alt=""/><br /><sub><b>Brian Kung</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=briankung" title="Code">💻</a> <a href="#content-briankung" title="Content">🖋</a></td>
+    <td align="center"><a href="https://rcousineau.gitlab.io"><img src="https://avatars3.githubusercontent.com/u/281039?v=4" width="100px;" alt=""/><br /><sub><b>Russell</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=miller-time" title="Code">💻</a></td>
+    <td align="center"><a href="http://danwilhelm.com"><img src="https://avatars3.githubusercontent.com/u/6137185?v=4" width="100px;" alt=""/><br /><sub><b>Dan Wilhelm</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=danwilhelm" title="Documentation">📖</a></td>
+    <td align="center"><a href="https://github.com/Jesse-Cameron"><img src="https://avatars3.githubusercontent.com/u/3723654?v=4" width="100px;" alt=""/><br /><sub><b>Jesse</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=Jesse-Cameron" title="Code">💻</a> <a href="#content-Jesse-Cameron" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/MrFroop"><img src="https://avatars3.githubusercontent.com/u/196700?v=4" width="100px;" alt=""/><br /><sub><b>Fredrik Jambrén</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=MrFroop" title="Code">💻</a></td>
     <td align="center"><a href="https://github.com/petemcfarlane"><img src="https://avatars3.githubusercontent.com/u/3472717?v=4" width="100px;" alt=""/><br /><sub><b>Pete McFarlane</b></sub></a><br /><a href="#content-petemcfarlane" title="Content">🖋</a></td>
   </tr>
   <tr>
-    <td align="center"><a href="https://github.com/nkanderson"><img src="https://avatars0.githubusercontent.com/u/4128825?v=4" width="100px;" alt=""/><br /><sub><b>nkanderson</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=nkanderson" title="Code">💻</a> <a href="#content-nkanderson" title="Content">🖋</a></td>
-    <td align="center"><a href="https://github.com/ajaxm"><img src="https://avatars0.githubusercontent.com/u/13360138?v=4" width="100px;" alt=""/><br /><sub><b>Ajax M</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=ajaxm" title="Documentation">📖</a></td>
+    <td align="center"><a href="https://github.com/nkanderson"><img src="https://avatars0.githubusercontent.com/u/4128825?v=4" width="100px;" alt=""/><br /><sub><b>nkanderson</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=nkanderson" title="Code">💻</a> <a href="#content-nkanderson" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/ajaxm"><img src="https://avatars0.githubusercontent.com/u/13360138?v=4" width="100px;" alt=""/><br /><sub><b>Ajax M</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=ajaxm" title="Documentation">📖</a></td>
     <td align="center"><a href="https://dylnuge.com"><img src="https://avatars2.githubusercontent.com/u/118624?v=4" width="100px;" alt=""/><br /><sub><b>Dylan Nugent</b></sub></a><br /><a href="#content-Dylnuge" title="Content">🖋</a></td>
-    <td align="center"><a href="https://github.com/vyaslav"><img src="https://avatars0.githubusercontent.com/u/1385427?v=4" width="100px;" alt=""/><br /><sub><b>vyaslav</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=vyaslav" title="Code">💻</a> <a href="#content-vyaslav" title="Content">🖋</a></td>
-    <td align="center"><a href="https://join.sfxd.org"><img src="https://avatars1.githubusercontent.com/u/17297466?v=4" width="100px;" alt=""/><br /><sub><b>George</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=gdoenlen" title="Code">💻</a></td>
-    <td align="center"><a href="https://github.com/nyxtom"><img src="https://avatars2.githubusercontent.com/u/222763?v=4" width="100px;" alt=""/><br /><sub><b>Thomas Holloway</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=nyxtom" title="Code">💻</a> <a href="#content-nyxtom" title="Content">🖋</a></td>
-    <td align="center"><a href="https://github.com/workingjubilee"><img src="https://avatars1.githubusercontent.com/u/46493976?v=4" width="100px;" alt=""/><br /><sub><b>Jubilee</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=workingjubilee" title="Code">💻</a></td>
-    <td align="center"><a href="https://github.com/WofWca"><img src="https://avatars1.githubusercontent.com/u/39462442?v=4" width="100px;" alt=""/><br /><sub><b>WofWca</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=WofWca" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/vyaslav"><img src="https://avatars0.githubusercontent.com/u/1385427?v=4" width="100px;" alt=""/><br /><sub><b>vyaslav</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=vyaslav" title="Code">💻</a> <a href="#content-vyaslav" title="Content">🖋</a></td>
+    <td align="center"><a href="https://join.sfxd.org"><img src="https://avatars1.githubusercontent.com/u/17297466?v=4" width="100px;" alt=""/><br /><sub><b>George</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=gdoenlen" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/nyxtom"><img src="https://avatars2.githubusercontent.com/u/222763?v=4" width="100px;" alt=""/><br /><sub><b>Thomas Holloway</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=nyxtom" title="Code">💻</a> <a href="#content-nyxtom" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/workingjubilee"><img src="https://avatars1.githubusercontent.com/u/46493976?v=4" width="100px;" alt=""/><br /><sub><b>Jubilee</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=workingjubilee" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/WofWca"><img src="https://avatars1.githubusercontent.com/u/39462442?v=4" width="100px;" alt=""/><br /><sub><b>WofWca</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=WofWca" title="Code">💻</a></td>
   </tr>
   <tr>
-    <td align="center"><a href="https://github.com/jrvidal"><img src="https://avatars0.githubusercontent.com/u/1636604?v=4" width="100px;" alt=""/><br /><sub><b>Roberto Vidal</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=jrvidal" title="Code">💻</a> <a href="https://github.com/fmoko/rustlings/commits?author=jrvidal" title="Documentation">📖</a> <a href="#ideas-jrvidal" title="Ideas, Planning, & Feedback">🤔</a> <a href="#maintenance-jrvidal" title="Maintenance">🚧</a></td>
-    <td align="center"><a href="https://github.com/jensim"><img src="https://avatars0.githubusercontent.com/u/3663856?v=4" width="100px;" alt=""/><br /><sub><b>Jens</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=jensim" title="Documentation">📖</a></td>
-    <td align="center"><a href="http://rahatah.me/d"><img src="https://avatars3.githubusercontent.com/u/3174006?v=4" width="100px;" alt=""/><br /><sub><b>Rahat Ahmed</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=rahatarmanahmed" title="Documentation">📖</a></td>
-    <td align="center"><a href="https://github.com/AbdouSeck"><img src="https://avatars2.githubusercontent.com/u/6490055?v=4" width="100px;" alt=""/><br /><sub><b>Abdou Seck</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=AbdouSeck" title="Code">💻</a> <a href="#content-AbdouSeck" title="Content">🖋</a> <a href="https://github.com/fmoko/rustlings/pulls?q=is%3Apr+reviewed-by%3AAbdouSeck" title="Reviewed Pull Requests">👀</a></td>
-    <td align="center"><a href="https://codehearts.com"><img src="https://avatars0.githubusercontent.com/u/2885412?v=4" width="100px;" alt=""/><br /><sub><b>Katie</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=codehearts" title="Code">💻</a></td>
-    <td align="center"><a href="https://github.com/Socratides"><img src="https://avatars3.githubusercontent.com/u/27732983?v=4" width="100px;" alt=""/><br /><sub><b>Socrates</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=Socratides" title="Documentation">📖</a></td>
+    <td align="center"><a href="https://github.com/jrvidal"><img src="https://avatars0.githubusercontent.com/u/1636604?v=4" width="100px;" alt=""/><br /><sub><b>Roberto Vidal</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=jrvidal" title="Code">💻</a> <a href="https://github.com/rust-lang/rustlings/commits?author=jrvidal" title="Documentation">📖</a> <a href="#ideas-jrvidal" title="Ideas, Planning, & Feedback">🤔</a> <a href="#maintenance-jrvidal" title="Maintenance">🚧</a></td>
+    <td align="center"><a href="https://github.com/jensim"><img src="https://avatars0.githubusercontent.com/u/3663856?v=4" width="100px;" alt=""/><br /><sub><b>Jens</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=jensim" title="Documentation">📖</a></td>
+    <td align="center"><a href="http://rahatah.me/d"><img src="https://avatars3.githubusercontent.com/u/3174006?v=4" width="100px;" alt=""/><br /><sub><b>Rahat Ahmed</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=rahatarmanahmed" title="Documentation">📖</a></td>
+    <td align="center"><a href="https://github.com/AbdouSeck"><img src="https://avatars2.githubusercontent.com/u/6490055?v=4" width="100px;" alt=""/><br /><sub><b>Abdou Seck</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=AbdouSeck" title="Code">💻</a> <a href="#content-AbdouSeck" title="Content">🖋</a> <a href="https://github.com/rust-lang/rustlings/pulls?q=is%3Apr+reviewed-by%3AAbdouSeck" title="Reviewed Pull Requests">👀</a></td>
+    <td align="center"><a href="https://codehearts.com"><img src="https://avatars0.githubusercontent.com/u/2885412?v=4" width="100px;" alt=""/><br /><sub><b>Katie</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=codehearts" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/Socratides"><img src="https://avatars3.githubusercontent.com/u/27732983?v=4" width="100px;" alt=""/><br /><sub><b>Socrates</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=Socratides" title="Documentation">📖</a></td>
     <td align="center"><a href="https://github.com/gnodarse"><img src="https://avatars3.githubusercontent.com/u/46761795?v=4" width="100px;" alt=""/><br /><sub><b>gnodarse</b></sub></a><br /><a href="#content-gnodarse" title="Content">🖋</a></td>
-    <td align="center"><a href="https://github.com/harrisonmetz"><img src="https://avatars1.githubusercontent.com/u/7883408?v=4" width="100px;" alt=""/><br /><sub><b>Harrison Metzger</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=harrisonmetz" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/harrisonmetz"><img src="https://avatars1.githubusercontent.com/u/7883408?v=4" width="100px;" alt=""/><br /><sub><b>Harrison Metzger</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=harrisonmetz" title="Code">💻</a></td>
   </tr>
   <tr>
-    <td align="center"><a href="https://github.com/TorbenJ"><img src="https://avatars2.githubusercontent.com/u/9077102?v=4" width="100px;" alt=""/><br /><sub><b>Torben Jonas</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=TorbenJ" title="Code">💻</a> <a href="#content-TorbenJ" title="Content">🖋</a></td>
-    <td align="center"><a href="http://paulbissex.com/"><img src="https://avatars0.githubusercontent.com/u/641?v=4" width="100px;" alt=""/><br /><sub><b>Paul Bissex</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=pbx" title="Documentation">📖</a></td>
-    <td align="center"><a href="https://github.com/sjmann"><img src="https://avatars0.githubusercontent.com/u/6589896?v=4" width="100px;" alt=""/><br /><sub><b>Steven Mann</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=sjmann" title="Code">💻</a> <a href="#content-sjmann" title="Content">🖋</a></td>
-    <td align="center"><a href="https://smmdb.net/"><img src="https://avatars2.githubusercontent.com/u/5855071?v=4" width="100px;" alt=""/><br /><sub><b>Mario Reder</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=Tarnadas" title="Code">💻</a> <a href="#content-Tarnadas" title="Content">🖋</a></td>
-    <td align="center"><a href="https://keybase.io/skim"><img src="https://avatars0.githubusercontent.com/u/47347?v=4" width="100px;" alt=""/><br /><sub><b>skim</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=sl4m" title="Code">💻</a></td>
-    <td align="center"><a href="https://github.com/sanjaykdragon"><img src="https://avatars1.githubusercontent.com/u/10261698?v=4" width="100px;" alt=""/><br /><sub><b>Sanjay K</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=sanjaykdragon" title="Code">💻</a> <a href="#content-sanjaykdragon" title="Content">🖋</a></td>
-    <td align="center"><a href="http://www.rohanjain.in"><img src="https://avatars1.githubusercontent.com/u/343499?v=4" width="100px;" alt=""/><br /><sub><b>Rohan Jain</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=crodjer" title="Code">💻</a></td>
-    <td align="center"><a href="https://www.saidaspen.se"><img src="https://avatars1.githubusercontent.com/u/7727687?v=4" width="100px;" alt=""/><br /><sub><b>Said Aspen</b></sub></a><br /><a href="https://github.com/fmoko/rustlings/commits?author=saidaspen" title="Code">💻</a> <a href="#content-saidaspen" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/TorbenJ"><img src="https://avatars2.githubusercontent.com/u/9077102?v=4" width="100px;" alt=""/><br /><sub><b>Torben Jonas</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=TorbenJ" title="Code">💻</a> <a href="#content-TorbenJ" title="Content">🖋</a></td>
+    <td align="center"><a href="http://paulbissex.com/"><img src="https://avatars0.githubusercontent.com/u/641?v=4" width="100px;" alt=""/><br /><sub><b>Paul Bissex</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=pbx" title="Documentation">📖</a></td>
+    <td align="center"><a href="https://github.com/sjmann"><img src="https://avatars0.githubusercontent.com/u/6589896?v=4" width="100px;" alt=""/><br /><sub><b>Steven Mann</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=sjmann" title="Code">💻</a> <a href="#content-sjmann" title="Content">🖋</a></td>
+    <td align="center"><a href="https://smmdb.net/"><img src="https://avatars2.githubusercontent.com/u/5855071?v=4" width="100px;" alt=""/><br /><sub><b>Mario Reder</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=Tarnadas" title="Code">💻</a> <a href="#content-Tarnadas" title="Content">🖋</a></td>
+    <td align="center"><a href="https://keybase.io/skim"><img src="https://avatars0.githubusercontent.com/u/47347?v=4" width="100px;" alt=""/><br /><sub><b>skim</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=sl4m" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/sanjaykdragon"><img src="https://avatars1.githubusercontent.com/u/10261698?v=4" width="100px;" alt=""/><br /><sub><b>Sanjay K</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=sanjaykdragon" title="Code">💻</a> <a href="#content-sanjaykdragon" title="Content">🖋</a></td>
+    <td align="center"><a href="http://www.rohanjain.in"><img src="https://avatars1.githubusercontent.com/u/343499?v=4" width="100px;" alt=""/><br /><sub><b>Rohan Jain</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=crodjer" title="Code">💻</a></td>
+    <td align="center"><a href="https://www.saidaspen.se"><img src="https://avatars1.githubusercontent.com/u/7727687?v=4" width="100px;" alt=""/><br /><sub><b>Said Aspen</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=saidaspen" title="Code">💻</a> <a href="#content-saidaspen" title="Content">🖋</a></td>
+  </tr>
+  <tr>
+    <td align="center"><a href="https://github.com/uce"><img src="https://avatars3.githubusercontent.com/u/1756620?v=4" width="100px;" alt=""/><br /><sub><b>Ufuk Celebi</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=uce" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/lebedevsergey"><img src="https://avatars2.githubusercontent.com/u/7325764?v=4" width="100px;" alt=""/><br /><sub><b>lebedevsergey</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=lebedevsergey" title="Documentation">📖</a></td>
+    <td align="center"><a href="https://github.com/avrong"><img src="https://avatars2.githubusercontent.com/u/6342851?v=4" width="100px;" alt=""/><br /><sub><b>Aleksei Trifonov</b></sub></a><br /><a href="#content-avrong" title="Content">🖋</a></td>
+    <td align="center"><a href="https://drn.ie"><img src="https://avatars2.githubusercontent.com/u/411136?v=4" width="100px;" alt=""/><br /><sub><b>Darren Meehan</b></sub></a><br /><a href="#content-Darrenmeehan" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/jihchi"><img src="https://avatars1.githubusercontent.com/u/87983?v=4" width="100px;" alt=""/><br /><sub><b>Jihchi Lee</b></sub></a><br /><a href="#content-jihchi" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/bertonha"><img src="https://avatars3.githubusercontent.com/u/1225902?v=4" width="100px;" alt=""/><br /><sub><b>Christofer Bertonha</b></sub></a><br /><a href="#content-bertonha" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/apatniv"><img src="https://avatars2.githubusercontent.com/u/22565917?v=4" width="100px;" alt=""/><br /><sub><b>Vivek Bharath Akupatni</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=apatniv" title="Code">💻</a> <a href="https://github.com/rust-lang/rustlings/commits?author=apatniv" title="Tests">⚠️</a></td>
+    <td align="center"><a href="https://github.com/DiD92"><img src="https://avatars3.githubusercontent.com/u/6002416?v=4" width="100px;" alt=""/><br /><sub><b>Dídac Sementé Fernández</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=DiD92" title="Code">💻</a> <a href="#content-DiD92" title="Content">🖋</a></td>
+  </tr>
+  <tr>
+    <td align="center"><a href="https://github.com/wrobstory"><img src="https://avatars3.githubusercontent.com/u/2601457?v=4" width="100px;" alt=""/><br /><sub><b>Rob Story</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=wrobstory" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/siobhanjacobson"><img src="https://avatars2.githubusercontent.com/u/28983835?v=4" width="100px;" alt=""/><br /><sub><b>Siobhan Jacobson</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=siobhanjacobson" title="Code">💻</a></td>
+    <td align="center"><a href="https://www.linkedin.com/in/evancarroll/"><img src="https://avatars2.githubusercontent.com/u/19922?v=4" width="100px;" alt=""/><br /><sub><b>Evan Carroll</b></sub></a><br /><a href="#content-EvanCarroll" title="Content">🖋</a></td>
+    <td align="center"><a href="http://www.jawaadmahmood.com"><img src="https://avatars3.githubusercontent.com/u/95606?v=4" width="100px;" alt=""/><br /><sub><b>Jawaad Mahmood</b></sub></a><br /><a href="#content-jmahmood" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/GaurangTandon"><img src="https://avatars1.githubusercontent.com/u/6308683?v=4" width="100px;" alt=""/><br /><sub><b>Gaurang Tandon</b></sub></a><br /><a href="#content-GaurangTandon" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/dev-cyprium"><img src="https://avatars1.githubusercontent.com/u/6002628?v=4" width="100px;" alt=""/><br /><sub><b>Stefan Kupresak</b></sub></a><br /><a href="#content-dev-cyprium" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/greg-el"><img src="https://avatars3.githubusercontent.com/u/45019882?v=4" width="100px;" alt=""/><br /><sub><b>Greg Leonard</b></sub></a><br /><a href="#content-greg-el" title="Content">🖋</a></td>
+    <td align="center"><a href="https://ryanpcmcquen.org"><img src="https://avatars3.githubusercontent.com/u/772937?v=4" width="100px;" alt=""/><br /><sub><b>Ryan McQuen</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=ryanpcmcquen" title="Code">💻</a></td>
+  </tr>
+  <tr>
+    <td align="center"><a href="https://github.com/AnnikaCodes"><img src="https://avatars3.githubusercontent.com/u/56906084?v=4" width="100px;" alt=""/><br /><sub><b>Annika</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/pulls?q=is%3Apr+reviewed-by%3AAnnikaCodes" title="Reviewed Pull Requests">👀</a></td>
+    <td align="center"><a href="https://darnuria.eu"><img src="https://avatars1.githubusercontent.com/u/2827553?v=4" width="100px;" alt=""/><br /><sub><b>Axel Viala</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=darnuria" title="Code">💻</a></td>
+    <td align="center"><a href="https://sazid.github.io"><img src="https://avatars1.githubusercontent.com/u/2370167?v=4" width="100px;" alt=""/><br /><sub><b>Mohammed Sazid Al Rashid</b></sub></a><br /><a href="#content-sazid" title="Content">🖋</a> <a href="https://github.com/rust-lang/rustlings/commits?author=sazid" title="Code">💻</a></td>
+    <td align="center"><a href="https://codingthemsoftly.com"><img src="https://avatars1.githubusercontent.com/u/17479099?v=4" width="100px;" alt=""/><br /><sub><b>Caleb Webber</b></sub></a><br /><a href="#maintenance-seeplusplus" title="Maintenance">🚧</a></td>
   </tr>
 </table>
 

exercises/collections/README.md

@@ -0,0 +1,20 @@
+### Collections
+
+Rust’s standard library includes a number of very useful data
+structures called collections. Most other data types represent one
+specific value, but collections can contain multiple values. Unlike
+the built-in array and tuple types, the data these collections point
+to is stored on the heap, which means the amount of data does not need
+to be known at compile time and can grow or shrink as the program
+runs.
+
+This exercise will get you familiar with two fundamental data
+structures that are used very often in Rust programs:
+
+* A *vector* allows you to store a variable number of values next to
+  each other.
+* A *hash map* allows you to associate a value with a particular key.
+  You may also know this by the names *map* in C++, *dictionary* in
+  Python or an *associative array* in other languages.
+
+[Rust book chapter](https://doc.rust-lang.org/stable/book/ch08-01-vectors.html)

exercises/collections/hashmap1.rs

@@ -0,0 +1,46 @@
+// hashmap1.rs
+// A basket of fruits in the form of a hash map needs to be defined.
+// The key represents the name of the fruit and the value represents
+// how many of that particular fruit is in the basket. You have to put
+// at least three different types of fruits (e.g apple, banana, mango)
+// in the basket and the total count of all the fruits should be at
+// least five.
+//
+// Make me compile and pass the tests!
+//
+// Execute the command `rustlings hint collections3` if you need
+// hints.
+
+// I AM NOT DONE
+
+use std::collections::HashMap;
+
+fn fruit_basket() -> HashMap<String, u32> {
+    let mut basket = // TODO: declare your hash map here.
+
+    // Two bananas are already given for you :)
+    basket.insert(String::from("banana"), 2);
+
+    // TODO: Put more fruits in your basket here.
+
+    basket
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn at_least_three_types_of_fruits() {
+        let basket = fruit_basket();
+        assert!(basket.len() >= 3);
+    }
+
+    #[test]
+    fn at_least_five_fruits() {
+        let basket = fruit_basket();
+        assert!(basket
+            .values()
+            .sum::<u32>() >= 5);
+    }
+}

exercises/collections/hashmap2.rs

@@ -0,0 +1,83 @@
+// hashmap2.rs
+
+// A basket of fruits in the form of a hash map is given. The key
+// represents the name of the fruit and the value represents how many
+// of that particular fruit is in the basket. You have to put *MORE
+// THAN 11* fruits in the basket. Three types of fruits - Apple (4),
+// Mango (2) and Lichi (5) are already given in the basket. You are
+// not allowed to insert any more of these fruits!
+//
+// Make me pass the tests!
+//
+// Execute the command `rustlings hint collections4` if you need
+// hints.
+
+// I AM NOT DONE
+
+use std::collections::HashMap;
+
+#[derive(Hash, PartialEq, Eq)]
+enum Fruit {
+    Apple,
+    Banana,
+    Mango,
+    Lichi,
+    Pineapple,
+}
+
+fn fruit_basket(basket: &mut HashMap<Fruit, u32>) {
+    let fruit_kinds = vec![
+        Fruit::Apple,
+        Fruit::Banana,
+        Fruit::Mango,
+        Fruit::Lichi,
+        Fruit::Pineapple,
+    ];
+
+    for fruit in fruit_kinds {
+        // TODO: Put new fruits if not already present. Note that you
+        // are not allowed to put any type of fruit that's already
+        // present!
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn get_fruit_basket() -> HashMap<Fruit, u32> {
+        let mut basket = HashMap::<Fruit, u32>::new();
+        basket.insert(Fruit::Apple, 4);
+        basket.insert(Fruit::Mango, 2);
+        basket.insert(Fruit::Lichi, 5);
+
+        basket
+    }
+
+    #[test]
+    fn test_given_fruits_are_not_modified() {
+        let mut basket = get_fruit_basket();
+        fruit_basket(&mut basket);
+        assert_eq!(*basket.get(&Fruit::Apple).unwrap(), 4);
+        assert_eq!(*basket.get(&Fruit::Mango).unwrap(), 2);
+        assert_eq!(*basket.get(&Fruit::Lichi).unwrap(), 5);
+    }
+
+    #[test]
+    fn at_least_five_types_of_fruits() {
+        let mut basket = get_fruit_basket();
+        fruit_basket(&mut basket);
+        let count_fruit_kinds = basket.len();
+        assert!(count_fruit_kinds == 5);
+    }
+
+    #[test]
+    fn greater_than_eleven_fruits() {
+        let mut basket = get_fruit_basket();
+        fruit_basket(&mut basket);
+        let count = basket
+            .values()
+            .sum::<u32>();
+        assert!(count > 11);
+    }
+}

exercises/collections/vec1.rs

@@ -0,0 +1,25 @@
+// vec1.rs
+// Your task is to create a `Vec` which holds the exact same elements
+// as in the array `a`.
+// Make me compile and pass the test!
+// Execute the command `rustlings hint collections1` if you need hints.
+
+// I AM NOT DONE
+
+fn array_and_vec() -> ([i32; 4], Vec<i32>) {
+    let a = [10, 20, 30, 40]; // a plain array
+    let v = // TODO: declare your vector here with the macro for vectors
+
+    (a, v)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_array_and_vec_similarity() {
+        let (a, v) = array_and_vec();
+        assert!(a.iter().zip(v.iter()).all(|(x, y)| x == y));
+    }
+}

exercises/collections/vec2.rs

@@ -0,0 +1,38 @@
+// vec2.rs
+// A Vec of even numbers is given. Your task is to complete the loop
+// so that each number in the Vec is multiplied by 2.
+//
+// Make me pass the test!
+//
+// Execute the command `rustlings hint collections2` if you need
+// hints.
+
+// I AM NOT DONE
+
+fn vec_loop(mut v: Vec<i32>) -> Vec<i32> {
+    for i in v.iter_mut() {
+        // TODO: Fill this up so that each element in the Vec `v` is
+        // multiplied by 2.
+    }
+
+    // At this point, `v` should be equal to [4, 8, 12, 16, 20].
+    v
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_vec_loop() {
+        let v: Vec<i32> = (1..).filter(|x| x % 2 == 0).take(5).collect();
+        let ans = vec_loop(v.clone());
+
+        assert_eq!(
+            ans,
+            v.iter()
+                .map(|x| x * 2)
+                .collect::<Vec<i32>>()
+        );
+    }
+}

exercises/conversions/as_ref_mut.rs

@@ -3,6 +3,7 @@
 // and https://doc.rust-lang.org/std/convert/trait.AsMut.html, respectively.
 
 // I AM NOT DONE
+
 // Obtain the number of bytes (not characters) in the given argument
 // Add the AsRef trait appropriately as a trait bound
 fn byte_counter<T>(arg: T) -> usize {

exercises/conversions/from_into.rs

@@ -18,7 +18,6 @@ impl Default for Person {
     }
 }
 
-// I AM NOT DONE
 // Your task is to complete this implementation
 // in order for the line `let p = Person::from("Mark,20")` to compile
 // Please note that you'll need to parse the age component into a `usize`
@@ -33,6 +32,9 @@ impl Default for Person {
 // 5. Extract the other element from the split operation and parse it into a `usize` as the age
 // If while parsing the age, something goes wrong, then return the default of Person
 // Otherwise, then return an instantiated Person object with the results
+
+// I AM NOT DONE
+
 impl From<&str> for Person {
     fn from(s: &str) -> Person {
     }
@@ -73,7 +75,7 @@ mod tests {
     }
     #[test]
     fn test_bad_age() {
-        // Test that "Mark.twenty" will return the default person due to an error in parsing age
+        // Test that "Mark,twenty" will return the default person due to an error in parsing age
         let p = Person::from("Mark,twenty");
         assert_eq!(p.name, "John");
         assert_eq!(p.age, 30);

exercises/conversions/from_str.rs

@@ -82,5 +82,4 @@ mod tests {
     fn missing_name_and_invalid_age() {
         ",one".parse::<Person>().unwrap();
     }
-
 }

exercises/conversions/try_from_into.rs

@@ -2,9 +2,9 @@
 // Basically, this is the same as From. The main difference is that this should return a Result type
 // instead of the target type itself.
 // You can read more about it at https://doc.rust-lang.org/std/convert/trait.TryFrom.html
-use std::convert::{TryInto, TryFrom};
+use std::convert::{TryFrom, TryInto};
 
-#[derive(Debug)]
+#[derive(Debug, PartialEq)]
 struct Color {
     red: u8,
     green: u8,
@@ -25,22 +25,19 @@ struct Color {
 // Tuple implementation
 impl TryFrom<(i16, i16, i16)> for Color {
     type Error = String;
-    fn try_from(tuple: (i16, i16, i16)) -> Result<Self, Self::Error> {
-    }
+    fn try_from(tuple: (i16, i16, i16)) -> Result<Self, Self::Error> {}
 }
 
 // Array implementation
 impl TryFrom<[i16; 3]> for Color {
     type Error = String;
-    fn try_from(arr: [i16; 3]) -> Result<Self, Self::Error> {
-    }
+    fn try_from(arr: [i16; 3]) -> Result<Self, Self::Error> {}
 }
 
 // Slice implementation
 impl TryFrom<&[i16]> for Color {
     type Error = String;
-    fn try_from(slice: &[i16]) -> Result<Self, Self::Error> {
-    }
+    fn try_from(slice: &[i16]) -> Result<Self, Self::Error> {}
 }
 
 fn main() {
@@ -66,65 +63,93 @@ mod tests {
     use super::*;
 
     #[test]
-    #[should_panic]
     fn test_tuple_out_of_range_positive() {
-        let _ = Color::try_from((256, 1000, 10000)).unwrap();
+        assert!(Color::try_from((256, 1000, 10000)).is_err());
     }
     #[test]
-    #[should_panic]
     fn test_tuple_out_of_range_negative() {
-        let _ = Color::try_from((-1, -10, -256)).unwrap();
+        assert!(Color::try_from((-1, -10, -256)).is_err());
+    }
+    #[test]
+    fn test_tuple_sum() {
+        assert!(Color::try_from((-1, 255, 255)).is_err());
     }
     #[test]
     fn test_tuple_correct() {
-        let c: Color = (183, 65, 14).try_into().unwrap();
-        assert_eq!(c.red, 183);
-        assert_eq!(c.green, 65);
-        assert_eq!(c.blue, 14);
+        let c: Result<Color, String> = (183, 65, 14).try_into();
+        assert_eq!(
+            c,
+            Ok(Color {
+                red: 183,
+                green: 65,
+                blue: 14
+            })
+        );
     }
-
     #[test]
-    #[should_panic]
     fn test_array_out_of_range_positive() {
-        let _: Color = [1000, 10000, 256].try_into().unwrap();
+        let c: Color = [1000, 10000, 256].try_into();
+        assert!(c.is_err());
     }
     #[test]
-    #[should_panic]
     fn test_array_out_of_range_negative() {
-        let _: Color = [-10, -256, -1].try_into().unwrap();
+        let c: Color = [-10, -256, -1].try_into();
+        assert!(c.is_err());
     }
     #[test]
+    fn test_array_sum() {
+        let c: Color = [-1, 255, 255].try_into();
+        assert!(c.is_err());
+    }
+    #[test]
+    #[test]
     fn test_array_correct() {
-        let c: Color = [183, 65, 14].try_into().unwrap();
-        assert_eq!(c.red, 183);
-        assert_eq!(c.green, 65);
-        assert_eq!(c.blue, 14);
+        let c: Result<Color, String> = [183, 65, 14].try_into();
+        assert_eq!(
+            c,
+            Ok(Color {
+                red: 183,
+                green: 65,
+                blue: 14
+            })
+        );
     }
-
     #[test]
-    #[should_panic]
     fn test_slice_out_of_range_positive() {
         let arr = [10000, 256, 1000];
-        let _ = Color::try_from(&arr[..]).unwrap();
+        assert!(Color::try_from(&arr[..]).is_err());
     }
     #[test]
-    #[should_panic]
     fn test_slice_out_of_range_negative() {
         let arr = [-256, -1, -10];
-        let _ = Color::try_from(&arr[..]).unwrap();
+        assert!(Color::try_from(&arr[..]).is_err());
+    }
+    #[test]
+    fn test_slice_sum() {
+        let arr = [-1, 255, 255];
+        assert!(Color::try_from(&arr[..]).is_err());
     }
     #[test]
     fn test_slice_correct() {
         let v = vec![183, 65, 14];
-        let c = Color::try_from(&v[..]).unwrap();
-        assert_eq!(c.red, 183);
-        assert_eq!(c.green, 65);
-        assert_eq!(c.blue, 14);
+        let c: Result<Color, String> = Color::try_from(&v[..]);
+        assert_eq!(
+            c,
+            Ok(Color {
+                red: 183,
+                green: 65,
+                blue: 14
+            })
+        );
     }
     #[test]
-    #[should_panic]
     fn test_slice_excess_length() {
         let v = vec![0, 0, 0, 0];
-        let _ = Color::try_from(&v[..]).unwrap();
+        assert!(Color::try_from(&v[..]).is_err());
+    }
+    #[test]
+    fn test_slice_insufficient_length() {
+        let v = vec![0, 0];
+        assert!(Color::try_from(&v[..]).is_err());
     }
 }

exercises/conversions/using_as.rs

@@ -1,17 +1,28 @@
 // Type casting in Rust is done via the usage of the `as` operator.
 // Please note that the `as` operator is not only used when type casting.
 // It also helps with renaming imports.
+//
+// The goal is to make sure that the division does not fail to compile
+// and returns the proper type.
 
 // I AM NOT DONE
-// The goal is to make sure that the division does not fail to compile
+
 fn average(values: &[f64]) -> f64 {
-    let total = values
-        .iter()
-        .fold(0.0, |a, b| a + b);
+    let total = values.iter().fold(0.0, |a, b| a + b);
     total / values.len()
 }
 
 fn main() {
     let values = [3.5, 0.3, 13.0, 11.7];
     println!("{}", average(&values));
-}
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn returns_proper_type_and_value() {
+        assert_eq!(average(&[3.5, 0.3, 13.0, 11.7]), 7.125);
+    }
+}

exercises/enums/README.md

@@ -1,8 +1,8 @@
 ### Enums
 
-Rust allows you to define types called "enums" which enumerate possible values. 
+Rust allows you to define types called "enums" which enumerate possible values.
 Enums are a feature in many languages, but their capabilities differ in each language. Rust’s enums are most similar to algebraic data types in functional languages, such as F#, OCaml, and Haskell.
-Useful in combination with enums is Rust's "pattern matching" facility, which makes it easy to run different code for different values of an enumeration.  
+Useful in combination with enums is Rust's "pattern matching" facility, which makes it easy to run different code for different values of an enumeration.
 
 #### Book Sections
 

exercises/enums/enums2.rs

@@ -16,10 +16,10 @@ impl Message {
 
 fn main() {
     let messages = [
-        Message::Move{ x: 10, y: 30 },
+        Message::Move { x: 10, y: 30 },
         Message::Echo(String::from("hello world")),
         Message::ChangeColor(200, 255, 255),
-        Message::Quit
+        Message::Quit,
     ];
 
     for message in &messages {

exercises/enums/enums3.rs

@@ -9,13 +9,13 @@ enum Message {
 
 struct Point {
     x: u8,
-    y: u8
+    y: u8,
 }
 
 struct State {
     color: (u8, u8, u8),
     position: Point,
-    quit: bool
+    quit: bool,
 }
 
 impl State {
@@ -46,14 +46,14 @@ mod tests {
 
     #[test]
     fn test_match_message_call() {
-        let mut state = State{
+        let mut state = State {
             quit: false,
-            position: Point{ x: 0, y: 0 },
-            color: (0, 0, 0)
+            position: Point { x: 0, y: 0 },
+            color: (0, 0, 0),
         };
-        state.process(Message::ChangeColor(255, 0, 255));
+        state.process(Message::ChangeColor((255, 0, 255)));
         state.process(Message::Echo(String::from("hello world")));
-        state.process(Message::Move(Point{ x: 10, y: 15 }));
+        state.process(Message::Move(Point { x: 10, y: 15 }));
         state.process(Message::Quit);
 
         assert_eq!(state.color, (255, 0, 255));
@@ -61,5 +61,4 @@ mod tests {
         assert_eq!(state.position.y, 15);
         assert_eq!(state.quit, true);
     }
-
 }

exercises/error_handling/README.md

@@ -1,5 +1,5 @@
 For this exercise check out the sections:
-- [Error Handling](https://doc.rust-lang.org/book/ch09-02-recoverable-errors-with-result.html) 
-- [Generics](https://doc.rust-lang.org/book/ch10-01-syntax.html) 
+- [Error Handling](https://doc.rust-lang.org/book/ch09-02-recoverable-errors-with-result.html)
+- [Generics](https://doc.rust-lang.org/book/ch10-01-syntax.html)
 
 of the Rust Book.

exercises/generics/generics1.rs

@@ -1,4 +1,4 @@
-// This shopping list program isn't compiling! 
+// This shopping list program isn't compiling!
 // Use your knowledge of generics to fix it.
 
 // I AM NOT DONE
@@ -7,4 +7,3 @@ fn main() {
     let mut shopping_list: Vec<?> = Vec::new();
     shopping_list.push("milk");
 }
-

exercises/generics/generics2.rs

@@ -2,8 +2,9 @@
 // Rewrite it using generics so that it supports wrapping ANY type.
 
 // I AM NOT DONE
+
 struct Wrapper {
-    value: u32
+    value: u32,
 }
 
 impl Wrapper {
@@ -18,11 +19,11 @@ mod tests {
 
     #[test]
     fn store_u32_in_wrapper() {
-        assert_eq!(Wrapper::new(42).value,  42);
+        assert_eq!(Wrapper::new(42).value, 42);
     }
 
     #[test]
     fn store_str_in_wrapper() {
         assert_eq!(Wrapper::new("Foo").value, "Foo");
     }
-}
+}

exercises/generics/generics3.rs

@@ -1,13 +1,17 @@
 // An imaginary magical school has a new report card generation system written in Rust!
-// Currently the system only supports creating report cards where the student's grade 
-// is represented numerically (e.g. 1.0 -> 5.5). 
-// However, the school also issues alphabetical grades (A+ -> F-) and needs 
+// Currently the system only supports creating report cards where the student's grade
+// is represented numerically (e.g. 1.0 -> 5.5).
+// However, the school also issues alphabetical grades (A+ -> F-) and needs
 // to be able to print both types of report card!
 
-// Make the necessary code changes to support alphabetical report cards, thereby making 
-// the second test pass.
+// Make the necessary code changes in the struct ReportCard and the impl block
+// to support alphabetical report cards. Change the Grade in the second test to "A+"
+// to show that your changes allow alphabetical grades.
+
+// Execute 'rustlings hint generics3' for hints!
 
 // I AM NOT DONE
+
 pub struct ReportCard {
     pub grade: f32,
     pub student_name: String,
@@ -16,7 +20,7 @@ pub struct ReportCard {
 
 impl ReportCard {
     pub fn print(&self) -> String {
-        format!("{} ({}) - achieved a grade of {}", 
+        format!("{} ({}) - achieved a grade of {}",
             &self.student_name, &self.student_age, &self.grade)
     }
 }
@@ -28,21 +32,27 @@ mod tests {
     #[test]
     fn generate_numeric_report_card() {
         let report_card = ReportCard {
-            grade: 2.1, 
-            student_name: "Tom Wriggle".to_string(), 
+            grade: 2.1,
+            student_name: "Tom Wriggle".to_string(),
             student_age: 12,
         };
-        assert_eq!(report_card.print(), "Tom Wriggle (12) - achieved a grade of 2.1");
+        assert_eq!(
+            report_card.print(),
+            "Tom Wriggle (12) - achieved a grade of 2.1"
+        );
     }
 
     #[test]
     fn generate_alphabetic_report_card() {
         // TODO: Make sure to change the grade here after you finish the exercise.
         let report_card = ReportCard {
-            grade: 2.1, 
-            student_name: "Gary Plotter".to_string(), 
+            grade: 2.1,
+            student_name: "Gary Plotter".to_string(),
             student_age: 11,
         };
-        assert_eq!(report_card.print(), "Gary Plotter (11) - achieved a grade of A+");
+        assert_eq!(
+            report_card.print(),
+            "Gary Plotter (11) - achieved a grade of A+"
+        );
     }
-}
+}

exercises/primitive_types/primitive_types3.rs

@@ -1,5 +1,5 @@
 // primitive_types3.rs
-// Create an array with at least 100 elements in it where the ??? is. 
+// Create an array with at least 100 elements in it where the ??? is.
 // Execute `rustlings hint primitive_types3` for hints!
 
 // I AM NOT DONE

exercises/primitive_types/primitive_types6.rs

@@ -1,11 +1,16 @@
 // primitive_types6.rs
 // Use a tuple index to access the second element of `numbers`.
-// You can put this right into the `println!` where the ??? is.
+// You can put the expression for the second element where ??? is so that the test passes.
 // Execute `rustlings hint primitive_types6` for hints!
 
 // I AM NOT DONE
 
-fn main() {
+#[test]
+fn indexing_tuple() {
     let numbers = (1, 2, 3);
-    println!("The second number is {}", ???);
+    // Replace below ??? with the tuple indexing syntax.
+    let second = ???;
+
+    assert_eq!(2, second,
+        "This is not the 2nd number in the tuple!")
 }

exercises/quiz2.rs

@@ -17,14 +17,14 @@ fn string(arg: String) {
 }
 
 fn main() {
-    ("blue");
-    ("red".to_string());
-    (String::from("hi"));
-    ("rust is fun!".to_owned());
-    ("nice weather".into());
-    (format!("Interpolation {}", "Station"));
-    (&String::from("abc")[0..1]);
-    ("  hello there ".trim());
-    ("Happy Monday!".to_string().replace("Mon", "Tues"));
-    ("mY sHiFt KeY iS sTiCkY".to_lowercase());
+    ???("blue");
+    ???("red".to_string());
+    ???(String::from("hi"));
+    ???("rust is fun!".to_owned());
+    ???("nice weather".into());
+    ???(format!("Interpolation {}", "Station"));
+    ???(&String::from("abc")[0..1]);
+    ???("  hello there ".trim());
+    ???("Happy Monday!".to_string().replace("Mon", "Tues"));
+    ???("mY sHiFt KeY iS sTiCkY".to_lowercase());
 }

exercises/standard_library_types/README.md

@@ -3,5 +3,3 @@ For the Box exercise check out the chapter [Using Box to Point to Data on the He
 For the Arc exercise check out the chapter [Shared-State Concurrency](https://doc.rust-lang.org/book/ch16-03-shared-state.html) of the Rust Book.
 
 For the Iterator exercise check out the chapters [Iterator](https://doc.rust-lang.org/book/ch13-02-iterators.html) of the Rust Book and the [Iterator documentation](https://doc.rust-lang.org/stable/std/iter/).
-Do not adjust your monitors-- iterators1.rs is indeed missing. Iterators is a challenging topic, so we're leaving space for a simpler exercise!
-

exercises/standard_library_types/arc1.rs

@@ -21,7 +21,7 @@ fn main() {
             let mut sum = 0;
             while i < child_numbers.len() {
                 sum += child_numbers[i];
-                i += 5;
+                i += 8;
             }
             println!("Sum of offset {} is {}", offset, sum);
         }));

exercises/standard_library_types/box1.rs

@@ -26,7 +26,10 @@ pub enum List {
 
 fn main() {
     println!("This is an empty cons list: {:?}", create_empty_list());
-    println!("This is a non-empty cons list: {:?}", create_non_empty_list());
+    println!(
+        "This is a non-empty cons list: {:?}",
+        create_non_empty_list()
+    );
 }
 
 pub fn create_empty_list() -> List {

exercises/standard_library_types/iterators1.rs

@@ -0,0 +1,24 @@
+// iterators1.rs
+// 
+//  Make me compile by filling in the `???`s
+//
+// When performing operations on elements within a collection, iterators are essential.
+// This module helps you get familiar with the structure of using an iterator and 
+// how to go through elements within an iterable collection.
+// 
+// Execute `rustlings hint iterators1` for hints :D
+
+// I AM NOT DONE
+
+fn main () {
+    let my_fav_fruits = vec!["banana", "custard apple", "avocado", "peach", "raspberry"];
+
+    let mut my_iterable_fav_fruits = ???;   // TODO: Step 1
+
+    assert_eq!(my_iterable_fav_fruits.next(), Some(&"banana"));
+    assert_eq!(my_iterable_fav_fruits.next(), ???);     // TODO: Step 2
+    assert_eq!(my_iterable_fav_fruits.next(), Some(&"avocado"));
+    assert_eq!(my_iterable_fav_fruits.next(), ???);     // TODO: Step 2.1
+    assert_eq!(my_iterable_fav_fruits.next(), Some(&"raspberry"));
+    assert_eq!(my_iterable_fav_fruits.next(), ???);     // TODO: Step 3
+}

exercises/standard_library_types/iterators2.rs

@@ -1,5 +1,5 @@
 // iterators2.rs
-// In this module, you'll learn some of unique advantages that iterators can offer.
+// In this module, you'll learn some of the unique advantages that iterators can offer.
 // Step 1. Complete the `capitalize_first` function to pass the first two cases.
 // Step 2. Apply the `capitalize_first` function to a vector of strings.
 //         Ensure that it returns a vector of strings as well.

exercises/structs/structs3.rs

@@ -17,7 +17,11 @@ impl Package {
         if weight_in_grams <= 0 {
             // Something goes here...
         } else {
-            return Package {sender_country, recipient_country, weight_in_grams};
+            return Package {
+                sender_country,
+                recipient_country,
+                weight_in_grams,
+            };
         }
     }
 
@@ -25,8 +29,8 @@ impl Package {
         // Something goes here...
     }
 
-    fn get_fees(&self, cents_per_kg: i32) -> ??? {
-        // Something goes here... (beware of grams to kg conversion)
+    fn get_fees(&self, cents_per_gram: i32) -> ??? {
+        // Something goes here... 
     }
 }
 
@@ -47,7 +51,7 @@ mod tests {
     fn create_international_package() {
         let sender_country = String::from("Spain");
         let recipient_country = String::from("Russia");
-        
+
         let package = Package::new(sender_country, recipient_country, 1200);
 
         assert!(package.is_international());
@@ -58,10 +62,10 @@ mod tests {
         let sender_country = String::from("Spain");
         let recipient_country = String::from("Spain");
 
-        let cents_per_kg = ???;
-        
+        let cents_per_gram = ???;
+
         let package = Package::new(sender_country, recipient_country, 1500);
-        
-        assert_eq!(package.get_fees(cents_per_kg), 4500);
+
+        assert_eq!(package.get_fees(cents_per_gram), 4500);
     }
 }

exercises/tests/tests3.rs

@@ -18,4 +18,9 @@ mod tests {
     fn is_true_when_even() {
         assert!();
     }
+
+    #[test]
+    fn is_false_when_odd() {
+        assert!();
+    }
 }

exercises/traits/README.md

@@ -1,6 +1,6 @@
 ### Traits
 
-A trait is a collection of methods. 
+A trait is a collection of methods.
 
 Data types can implement traits. To do so, the methods making up the trait are defined for the data type. For example, the `String` data type implements the `From<&str>` trait. This allows a user to write `String::from("hello")`.
 
@@ -8,7 +8,7 @@ In this way, traits are somewhat similar to Java interfaces and C++ abstract cla
 
 Some additional common Rust traits include:
 
-+ `Clone` (the `clone` method), 
++ `Clone` (the `clone` method),
 + `Display` (which allows formatted display via `{}`), and
 + `Debug` (which allows formatted display via `{:?}`).
 
@@ -17,4 +17,4 @@ Because traits indicate shared behavior between data types, they are useful when
 
 #### Book Sections
 
-- [Traits](https://doc.rust-lang.org/book/ch10-02-traits.html)
+- [Traits](https://doc.rust-lang.org/book/ch10-02-traits.html)

exercises/traits/traits1.rs

@@ -1,21 +1,21 @@
 // traits1.rs
 // Time to implement some traits!
-// 
+//
 // Your task is to implement the trait
 // `AppendBar' for the type `String'.
-// 
+//
 // The trait AppendBar has only one function,
 // which appends "Bar" to any object
 // implementing this trait.
 
 // I AM NOT DONE
+
 trait AppendBar {
     fn append_bar(self) -> Self;
 }
 
 impl AppendBar for String {
     //Add your code here
-
 }
 
 fn main() {
@@ -40,5 +40,4 @@ mod tests {
             String::from("BarBar")
         );
     }
-
-}
+}

exercises/traits/traits2.rs

@@ -1,12 +1,12 @@
 // traits2.rs
-// 
+//
 // Your task is to implement the trait
 // `AppendBar' for a vector of strings.
-// 
+//
 // To implement this trait, consider for
 // a moment what it means to 'append "Bar"'
 // to a vector of strings.
-// 
+//
 // No boiler plate code this time,
 // you can do this!
 
@@ -18,9 +18,6 @@ trait AppendBar {
 
 //TODO: Add your code here
 
-
-
-
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -31,5 +28,4 @@ mod tests {
         assert_eq!(foo.pop().unwrap(), String::from("Bar"));
         assert_eq!(foo.pop().unwrap(), String::from("Foo"));
     }
-
 }

exercises/variables/variables5.rs

@@ -4,8 +4,8 @@
 // I AM NOT DONE
 
 fn main() {
-    let number = "3"; // don't change this line
-    println!("Number {}", number);
+    let number = "T-H-R-E-E";
+    println!("Spell a Number : {}", number);
     number = 3;
-    println!("Number {}", number);
+    println!("Number plus two is : {}", number + 2);
 }

info.toml

@@ -52,7 +52,7 @@ because we want to assign a different typed value to an existing variable. Somet
 you may also like to reuse existing variable names because you are just converting
 values to different types like in this exercise.
 Fortunately Rust has a powerful solution to this problem: 'Shadowing'!
-You can read more about 'Shadowing' in the book's section 'Variables and Mutability': 
+You can read more about 'Shadowing' in the book's section 'Variables and Mutability':
 https://doc.rust-lang.org/book/ch03-01-variables-and-mutability.html#shadowing
 Try to solve this exercise afterwards using this technique."""
 
@@ -61,13 +61,13 @@ name = "variables6"
 path = "exercises/variables/variables6.rs"
 mode = "compile"
 hint = """
-We know about variables and mutability, but there is another important type of 
-variable available; constants. 
-Constants are always immutable and they are declared with keyword 'const' rather 
+We know about variables and mutability, but there is another important type of
+variable available; constants.
+Constants are always immutable and they are declared with keyword 'const' rather
 than keyword 'let'.
 Constants types must also always be annotated.
 
-Read more about constants under 'Differences Between Variables and Constants' in the book's section 'Variables and Mutability': 
+Read more about constants under 'Differences Between Variables and Constants' in the book's section 'Variables and Mutability':
 https://doc.rust-lang.org/book/ch03-01-variables-and-mutability.html#differences-between-variables-and-constants
 """
 
@@ -210,7 +210,7 @@ of the tuple. You can do it!!"""
 [[exercises]]
 name = "primitive_types6"
 path = "exercises/primitive_types/primitive_types6.rs"
-mode = "compile"
+mode = "test"
 hint = """
 While you could use a destructuring `let` for the tuple here, try
 indexing into it instead, as explained in the last example of the
@@ -237,8 +237,8 @@ name = "structs2"
 path = "exercises/structs/structs2.rs"
 mode = "test"
 hint = """
-Creating instances of structs is easy, all you need to do is assign some values to its fields. 
-There is however some shortcuts that can be taken when instantiating structs. 
+Creating instances of structs is easy, all you need to do is assign some values to its fields.
+There is however some shortcuts that can be taken when instantiating structs.
 Have a look in The Book, to find out more: https://doc.rust-lang.org/stable/book/ch05-01-defining-structs.html#creating-instances-from-other-instances-with-struct-update-syntax"""
 
 [[exercises]]
@@ -370,6 +370,58 @@ its internal structure (the `fruits` and `veggies` modules and
 associated constants). It's almost there except for one keyword missing for
 each constant."""
 
+# COLLECTIONS
+
+[[exercises]]
+name = "collections1"
+path = "exercises/collections/vec1.rs"
+mode = "test"
+hint = """
+In Rust, there are two ways to define a Vector.
+
+1. One way is to use the `Vec::new()` function to create a new vector
+  and fill it with the `push()` method.
+
+2. The second way, which is simpler is to use the `vec![]` macro and
+  define your elements inside the square brackets.
+
+Check this chapter: https://doc.rust-lang.org/stable/book/ch08-01-vectors.html
+of the Rust book to learn more.
+"""
+
+[[exercises]]
+name = "collections2"
+path = "exercises/collections/vec2.rs"
+mode = "test"
+hint = """
+Hint 1: `i` is each element from the Vec as they are being iterated.
+  Can you try multiplying this?
+
+Hint 2: Check the suggestion from the compiler error ;)
+"""
+
+[[exercises]]
+name = "collections3"
+path = "exercises/collections/hashmap1.rs"
+mode = "test"
+hint = """
+Hint 1: Take a look at the return type of the function to figure out
+  the type for the `basket`.
+
+Hint 2: Number of fruits should be at least 5. And you have to put
+  at least three different types of fruits.
+"""
+
+[[exercises]]
+name = "collections4"
+path = "exercises/collections/hashmap2.rs"
+mode = "test"
+hint = """
+Use the `entry()` and `or_insert()` methods of `HashMap` to achieve this.
+
+Learn more at https://doc.rust-lang.org/stable/book/ch08-03-hash-maps.html#only-inserting-a-value-if-the-key-has-no-value
+"""
+
 # MACROS
 
 [[exercises]]
@@ -644,6 +696,27 @@ inside the loop but still in the main thread.
 `child_numbers` should be a clone of the Arc of the numbers instead of a
 thread-local copy of the numbers."""
 
+[[exercises]]
+name = "iterators1"
+path = "exercises/standard_library_types/iterators1.rs"
+mode = "compile"
+hint = """
+Step 1:
+We need to apply something to the collection `my_fav_fruits` before we start to go through
+it. What could that be? Take a look at the struct definition for a vector for inspiration:
+https://doc.rust-lang.org/std/vec/struct.Vec.html.
+
+
+Step 2 & step 2.1:
+Very similar to the lines above and below. You've got this!
+
+
+Step 3:
+An iterator goes through all elements in a collection, but what if we've run out of
+elements? What should we expect here? If you're stuck, take a look at 
+https://doc.rust-lang.org/std/iter/trait.Iterator.html for some ideas.
+"""
+
 [[exercises]]
 name = "iterators2"
 path = "exercises/standard_library_types/iterators2.rs"
@@ -682,8 +755,8 @@ name = "iterators4"
 path = "exercises/standard_library_types/iterators4.rs"
 mode = "test"
 hint = """
-In an imperative language, you might write a for loop that updates 
-a mutable variable. Or, you might write code utilizing recursion 
+In an imperative language, you might write a for loop that updates
+a mutable variable. Or, you might write code utilizing recursion
 and a match clause. In Rust you can take another functional
 approach, computing the factorial elegantly with ranges and iterators."""
 
@@ -703,10 +776,10 @@ name = "traits2"
 path = "exercises/traits/traits2.rs"
 mode = "test"
 hint = """
-Notice how the trait takes ownership of 'self',and returns `Self'. 
+Notice how the trait takes ownership of 'self',and returns `Self'.
 Try mutating the incoming string vector.
 
-Vectors provide suitable methods for adding an element at the end. See 
+Vectors provide suitable methods for adding an element at the end. See
 the documentation at: https://doc.rust-lang.org/std/vec/struct.Vec.html"""
 
 # Generics
@@ -724,7 +797,7 @@ name = "generics2"
 path = "exercises/generics/generics2.rs"
 mode = "test"
 hint = """
-Currently we are wrapping only values of type 'u32'. 
+Currently we are wrapping only values of type 'u32'.
 Maybe we could update the explicit references to this data type somehow?
 
 If you are still stuck https://doc.rust-lang.org/stable/book/ch10-01-syntax.html#in-method-definitions
@@ -735,7 +808,7 @@ name = "generics3"
 path = "exercises/generics/generics3.rs"
 mode = "test"
 hint = """
-To find the best solution to this challenge you're going to need to think back to your 
+To find the best solution to this challenge you're going to need to think back to your
 knowledge of traits, specifically Trait Bound Syntax -  you may also need this: "use std::fmt::Display;"
 
 This is definitely harder than the last two exercises! You need to think about not only making the
@@ -787,7 +860,7 @@ what you've learned :)"""
 [[exercises]]
 name = "using_as"
 path = "exercises/conversions/using_as.rs"
-mode = "compile"
+mode = "test"
 hint = """
 Use the `as` operator to cast one of the operands in the last line of the
 `average` function into the expected return type."""

install.ps1

@@ -35,7 +35,7 @@ if (Get-Command cargo -ErrorAction SilentlyContinue) {
 function vercomp($v1, $v2) {
     if ($v1 -eq $v2) {
        return 0
-    } 
+    }
 
     $v1 = $v1.Replace(".", "0")
     $v2 = $v2.Replace(".", "0")
@@ -53,7 +53,7 @@ function vercomp($v1, $v2) {
 }
 
 $rustVersion = $(rustc --version).Split(" ")[1]
-$minRustVersion = "1.31"
+$minRustVersion = "1.39"
 if ((vercomp $rustVersion $minRustVersion) -eq 2) {
     Write-Host "WARNING: Rust version is too old: $rustVersion - needs at least $minRustVersion"
     Write-Host "Please update Rust with 'rustup update'"

install.sh

@@ -87,7 +87,7 @@ function vercomp() {
 }
 
 RustVersion=$(rustc --version | cut -d " " -f 2)
-MinRustVersion=1.31
+MinRustVersion=1.39
 vercomp $RustVersion $MinRustVersion
 if [ $? -eq 2 ]
 then

src/exercise.rs

@@ -11,10 +11,15 @@ const I_AM_DONE_REGEX: &str = r"(?m)^\s*///?\s*I\s+AM\s+NOT\s+DONE";
 const CONTEXT: usize = 2;
 const CLIPPY_CARGO_TOML_PATH: &str = "./exercises/clippy/Cargo.toml";
 
-// Get a temporary file name that is hopefully unique to this process
+// Get a temporary file name that is hopefully unique
 #[inline]
 fn temp_file() -> String {
-    format!("./temp_{}", process::id())
+    let thread_id: String = format!("{:?}", std::thread::current().id())
+        .chars()
+        .filter(|c| c.is_alphanumeric())
+        .collect();
+
+    format!("./temp_{}_{}", process::id(), thread_id)
 }
 
 // The mode of the exercise.
@@ -167,9 +172,10 @@ path = "{}.rs""#,
     fn run(&self) -> Result<ExerciseOutput, ExerciseOutput> {
         let arg = match self.mode {
             Mode::Test => "--show-output",
-            _ => ""
+            _ => "",
         };
-        let cmd = Command::new(&temp_file()).arg(arg)
+        let cmd = Command::new(&temp_file())
+            .arg(arg)
             .output()
             .expect("Failed to run 'run' command");
 
@@ -314,7 +320,7 @@ mod test {
     #[test]
     fn test_exercise_with_output() {
         let exercise = Exercise {
-            name: "finished_exercise".into(),
+            name: "exercise_with_output".into(),
             path: PathBuf::from("tests/fixture/success/testSuccess.rs"),
             mode: Mode::Test,
             hint: String::new(),

src/main.rs

@@ -119,16 +119,19 @@ fn main() {
         verify(&exercises, verbose).unwrap_or_else(|_| std::process::exit(1));
     }
 
-    if matches.subcommand_matches("watch").is_some() && watch(&exercises, verbose).is_ok() {
+    if matches.subcommand_matches("watch").is_some() {
+        if let Err(e) = watch(&exercises, verbose) {
+            println!("Error: Could not watch your progess. Error message was {:?}.", e);
+            println!("Most likely you've run out of disk space or your 'inotify limit' has been reached.");
+            std::process::exit(1);
+        }
         println!(
             "{emoji} All exercises completed! {emoji}",
             emoji = Emoji("🎉", "★")
         );
         println!();
         println!("We hope you enjoyed learning about the various aspects of Rust!");
-        println!(
-            "If you noticed any issues, please don't hesitate to report them to our repo."
-        );
+        println!("If you noticed any issues, please don't hesitate to report them to our repo.");
         println!("You can also contribute your own exercises to help the greater community!");
         println!();
         println!("Before reporting an issue or contributing, please read our guidelines:");
@@ -143,15 +146,18 @@ fn main() {
 
 fn spawn_watch_shell(failed_exercise_hint: &Arc<Mutex<Option<String>>>) {
     let failed_exercise_hint = Arc::clone(failed_exercise_hint);
-    println!("Type 'hint' to get help");
+    println!("Type 'hint' to get help or 'clear' to clear the screen");
     thread::spawn(move || loop {
         let mut input = String::new();
         match io::stdin().read_line(&mut input) {
             Ok(_) => {
-                if input.trim().eq("hint") {
+                let input = input.trim();
+                if input.eq("hint") {
                     if let Some(hint) = &*failed_exercise_hint.lock().unwrap() {
                         println!("{}", hint);
                     }
+                } else if input.eq("clear") {
+                    println!("\x1B[2J\x1B[1;1H");
                 } else {
                     println!("unknown command: {}", input);
                 }

src/verify.rs

@@ -9,7 +9,7 @@ use indicatif::ProgressBar;
 // determines whether or not the test harness outputs are displayed.
 pub fn verify<'a>(
     start_at: impl IntoIterator<Item = &'a Exercise>,
-    verbose: bool
+    verbose: bool,
 ) -> Result<(), &'a Exercise> {
     for exercise in start_at {
         let compile_result = match exercise.mode {
@@ -65,6 +65,7 @@ fn compile_and_run_interactively(exercise: &Exercise) -> Result<bool, ()> {
         Err(output) => {
             warn!("Ran {} with errors", exercise);
             println!("{}", output.stdout);
+            println!("{}", output.stderr);
             return Err(());
         }
     };
@@ -76,9 +77,7 @@ fn compile_and_run_interactively(exercise: &Exercise) -> Result<bool, ()> {
 
 // Compile the given Exercise as a test harness and display
 // the output if verbose is set to true
-fn compile_and_test(
-    exercise: &Exercise, run_mode: RunMode, verbose: bool
-) -> Result<bool, ()> {
+fn compile_and_test(exercise: &Exercise, run_mode: RunMode, verbose: bool) -> Result<bool, ()> {
     let progress_bar = ProgressBar::new_spinner();
     progress_bar.set_message(format!("Testing {}...", exercise).as_str());
     progress_bar.enable_steady_tick(100);

tests/integration_tests.rs

@@ -180,4 +180,4 @@ fn run_single_test_success_without_output() {
         .assert()
         .code(0)
         .stdout(predicates::str::contains("THIS TEST TOO SHALL PAS").not());
-}
+}