diff --git a/src/todo/rust-basics.md b/src/todo/rust-basics.md index 9f077700f41..2b279e1c6c6 100644 --- a/src/todo/rust-basics.md +++ b/src/todo/rust-basics.md @@ -2,6 +2,28 @@ {{#include ../banners/hacktricks-training.md}} +### Ownership of variables + +Memory is managed through a system of ownership with the following rules that the compiler checks at compile time: + +1. Each value in Rust has a variable that's called its owner. +2. There can only be one owner at a time. +3. When the owner goes out of scope, the value will be dropped. + +```rust +fn main() { + let student_age: u32 = 20; + { // Scope of a variable is within the block it is declared in, which is denoted by brackets + let teacher_age: u32 = 41; + println!("The student is {} and teacher is {}", student_age, teacher_age); + } // when an owning variable goes out of scope, it will be dropped + + // println!("the teacher is {}", teacher_age); // this will not work as teacher_age has been dropped +} +``` + + + ### Generic Types Create a struct where 1 of their values could be any type @@ -34,6 +56,24 @@ pub enum Option { You can use functions such as `is_some()` or `is_none()` to check the value of the Option. + +### Result, Ok & Err + +Used for returning and propagating errors + +```rust +pub enum Result { + Ok(T), + Err(E), +} +``` + +You can use functions such as `is_ok()` or `is_err()` to check the value of the result + +The `Option` enum should be used in situations where a value might not exist (be `None`). +The `Result` enum should be used in situations where you do something that might go wrong + + ### Macros Macros are more powerful than functions because they expand to produce more code than the code you’ve written manually. For example, a function signature must declare the number and type of parameters the function has. Macros, on the other hand, can take a variable number of parameters: we can call `println!("hello")` with one argument or `println!("hello {}", name)` with two arguments. Also, macros are expanded before the compiler interprets the meaning of the code, so a macro can, for example, implement a trait on a given type. A function can’t, because it gets called at runtime and a trait needs to be implemented at compile time. @@ -363,6 +403,16 @@ Integrate it in CI and fail on `--deny warnings`. `cargo deny check advisories` offers similar functionality plus licence and ban-list checks. +#### Code coverage with cargo-tarpaulin + +`cargo tarpaulin` is a code coverage reporting tool for the Cargo build system + +```bash +cargo binstall cargo-tarpaulin +cargo tarpaulin # no options are required, if no root directory is defined Tarpaulin will run in the current working directory. +``` +On Linux, Tarpaulin's default tracing backend is still Ptrace and will only work on x86_64 processors. This can be changed to the llvm coverage instrumentation with `--engine llvm`. For Mac and Windows, this is the default collection method. + #### Supply-chain verification with cargo-vet (2024) `cargo vet` records a review hash for every crate you import and prevents unnoticed upgrades: