defer-lite

A Rust implementation of Go's defer statement as the defer! macro, which executes a block of code when the surrounding scope ends.

This crate focuses on providing a lightweight, high-performance, no_std implementation of the defer! macro.

Usage

Add the dependency in your Cargo.toml:

[dependencies]
defer-lite = "1.0.0"

Examples

Simplest example:

use defer_lite::defer; // import the defer! macro

fn main() {
    defer! { println!("Second"); }
    println!("First");
}

Multiple statements:

use defer_lite::defer;

fn main() {
    defer! {
        println!("Second");
        println!("Third");
    }
    println!("First");
}

In Go, the defer code runs when the function exits. In this Rust implementation, the code runs when the surrounding scope ends – this makes it possible to use defer inside loops:

use defer_lite::defer;

fn main() {
    defer! { println!("End"); }
    println!("Before");

    for i in 0..2 {
        defer! { println!("Defer {}", i); }
        println!("Loop {}", i);
    }

    println!("After");
}

License

Licensed under MIT license, see LICENSE.md for details.