# Introducing Rust

During all the sessions, I talked about quality in terms of code validation: you write tests to check your program; you build Docker images to provide everybody with a packaged environment.

But, quality also comes with the programming language itself.
During the last years, Rust emerged as the programming language to build (more) robust, safe software systems (compared to C++ and C).
Mozilla created Rust to replace C++ in the development of Firefox. Their goal is to have a language more focused on memory access and errors.

Rust has no garbage collector, compiles to native code.


Rust may make C++ and C deprecated during the coming decade(s).


## Installation

Rust installer: https://rustup.rs


Then, `rustup default stable`


Then, install the tutorials: 

`curl -L https://raw.githubusercontent.com/rust-lang/rustlings/main/install.sh | bash`


You can also run Rust code directly on:

https://play.rust-lang.org/



## Running Rustlings, the Rust tutorials


`cd rustlings`


Finally run to launch the exercises:

`~/.cargo/bin/rustlings watch`


Follow the given instructions while editing `rs` files with a text editor.


Focus on code quality:
- `variables4.rs`, what is the difference between mutability and immutability? Which relation with code safety? 
- You can skip the exercises on primitive types (by removing `// I AM NOT DONE`) as these are very simple and not related to the course.
- `vecs2.rs`. Rust has pointers as in C++/C. Why the second function (the one that uses `map`) should be used instead of the first one? (still related to mutability)
- `move_semantics1.rs`. As suggested by the *hint* command, why the code does not compile if you put `println!("{} has length {} content `{:?}`", "vec0", vec0.len(), vec0);` after the call to `fill_vec`? For that read: https://doc.rust-lang.org/stable/rust-by-example/scope/move.html On this point Rust strongly differs from C++/C/Java