How to Use Higher-Order Functions in Rust

Higher-order functions in Rust are functions that take other functions or closures as arguments or return them, enabling powerful abstractions like map, filter, and fold. You use them by passing closures (anonymous functions) to iterator methods or defining custom functions that accept function pointers or closures.

fn main() {
    let numbers = vec![1, 2, 3, 4, 5];
    let doubled: Vec<i32> = numbers.iter().map(|x| x * 2).collect();
    println!("{:?}", doubled); // [2, 4, 6, 8, 10]
}

Higher-order functions let you treat functions like data, passing them around to other functions to customize behavior without rewriting code. Think of it like handing a recipe to a chef who then decides how to cook your meal based on your specific instructions. You use this when you need to apply the same logic to many items or want to make your code more flexible and reusable.