How to Use Const Generics for Advanced Type-Level Programming

Use const generics by adding a const parameter to your struct or function definition to pass compile-time values like array sizes. This allows the compiler to generate specialized code for each size, enabling advanced type-level programming without runtime overhead.

struct ArrayWrapper<const N: usize> {
    data: [i32; N],
}

impl<const N: usize> ArrayWrapper<N> {
    fn new() -> Self {
        ArrayWrapper { data: [0; N] }
    }
}

fn main() {
    let a = ArrayWrapper::<5>::new();
    let b = ArrayWrapper::<10>::new();
}

Const generics let you pass fixed numbers, like array sizes, directly into your types so the compiler knows exactly how much memory to use. It is like ordering a custom-sized box where the size is stamped on the box itself, ensuring it fits perfectly without needing to measure it later.