Rust Macros

Contains a smorgasbord of advanced topics of interest, including unsafe Rust, macros, and more about lifetimes, traits, types, functions, and closures.

Unsafe Rust

opt out of some of Rust’s guarantees and take responsibility for manually upholding those guarantees.

Advanced traits

associated types, default type parameters, fully qualified syntax, supertraits, and new type pattern in relation to traits.

Advanced types

new type pattern, type aliases, the never type, and dynamically sized types.

Advanced functions and closures

function pointers and returning closures.

Macros

The ways to define code that defines more code at compile time.

What a macro is?

The term macro refers to a family of features in Rust: declarative macros with macro_rules! and three kinds of procedural macros:

• custom #[derive] macros that specify code added with the derive attribute used on structs and enums
• attribute-like macros that define custom attributes usable on any item
• function-like macros that look like function calls but operate ont eh tokens specified as their argument

Why we even need macros when we already have functions?

macros are a way of writing code that writes other code, which is known as metaprogramming, for example, write Rust code that writes Rust code

The additional power of macros

• can take a variable number of parameters
• macros are expanded before the complier interprets the meaning of the code
  • functions get called at runtime and a trait needs to be implemented ar compile time

downside

• macros more complex than functions definitions

How it works?

Need to add more contents.