Closures - Idiomatic Rust Snippets

Closures in Rust

Closures are anonymous functions that can capture their environment. They are similar to lambdas in other programming languages. Closures in Rust are defined using the | syntax.

Basic Syntax

#![allow(unused)]
fn main() {
let add = |a, b| a + b;
println!("Sum: {}", add(2, 3)); // Output: Sum: 5
}

Capturing Environment

Closures can capture variables from their enclosing scope.

#![allow(unused)]
fn main() {
let x = 10;
let print_x = || println!("x: {}", x);
print_x(); // Output: x: 10
}

Mutable Captures

Closures can also capture variables mutably.

#![allow(unused)]
fn main() {
let mut x = 10;
{
    let mut add_to_x = || x += 5;
    add_to_x();
}
println!("x: {}", x); // Output: x: 15
}

Moving Captures

Closures can take ownership of captured variables using the move keyword.

#![allow(unused)]
fn main() {
let x = vec![1, 2, 3];
let print_x = move || println!("x: {:?}", x);
print_x(); // Output: x: [1, 2, 3]
// x is no longer accessible here
}

Closures are a powerful feature in Rust, enabling concise and expressive code.