How to Write Compile-Time Assertions in Rust

Use the assert! macro with a boolean expression that must be true at compile time, or use a const function with a panic! to enforce constraints during compilation.

const fn assert_compile_time(condition: bool) {
    if !condition {
        panic!("Compile-time assertion failed");
    }
}

const MY_CONST: u32 = 10;
assert_compile_time(MY_CONST > 5);

Alternatively, use const_assert! from the standard library in newer Rust versions:

const_assert!(MY_CONST > 5);

Compile-time assertions check conditions while your code is being built, not when it runs. If the condition fails, the build stops immediately, preventing bad code from ever executing. Think of it as a safety inspector who checks the blueprints before construction begins, rather than inspecting the building after it's built.