seer/src/utils/static_assert.rs

29 lines
773 B
Rust

//! Static assert.
/// Assert a condition at compile-time.
///
/// See [RFC 2790] for potential addition into Rust itself.
///
/// [RFC 2790]: https://github.com/rust-lang/rfcs/issues/2790
///
/// # Examples
///
/// ```
/// use seer::utils::static_assert;
///
/// static_assert!(42 > 0);
/// ```
#[macro_export]
macro_rules! static_assert {
($condition:expr) => {
// Based on the latest one in `rustc`'s one before it was [removed].
//
// [removed]: https://github.com/rust-lang/rust/commit/c2dad1c6b9f9636198d7c561b47a2974f5103f6d
#[allow(dead_code)]
const _: () = [()][!($condition) as usize];
};
}
// I want it namespaced, even though it is exported to the root of the crate by `#[macro_export]`.
pub use static_assert;