linux/rust/kernel/static_assert.rs
Miguel Ojeda ef9e37973c rust: static_assert: add static_assert! macro
Add the `static_assert!` macro, which is a compile-time assert, similar
to the C11 `_Static_assert` and C++11 `static_assert` declarations [1,2].
Do so in a new module, called `static_assert`.

For instance:

    static_assert!(42 > 24);
    static_assert!(core::mem::size_of::<u8>() == 1);

    const X: &[u8] = b"bar";
    static_assert!(X[1] == b'a');

    const fn f(x: i32) -> i32 {
        x + 2
    }
    static_assert!(f(40) == 42);

Link: https://en.cppreference.com/w/c/language/_Static_assert [1]
Link: https://en.cppreference.com/w/cpp/language/static_assert [2]
Co-developed-by: Alex Gaynor <alex.gaynor@gmail.com>
Signed-off-by: Alex Gaynor <alex.gaynor@gmail.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-12-04 01:59:16 +01:00

35 lines
879 B
Rust

// SPDX-License-Identifier: GPL-2.0
//! Static assert.
/// Static assert (i.e. compile-time assert).
///
/// Similar to C11 [`_Static_assert`] and C++11 [`static_assert`].
///
/// The feature may be added to Rust in the future: see [RFC 2790].
///
/// [`_Static_assert`]: https://en.cppreference.com/w/c/language/_Static_assert
/// [`static_assert`]: https://en.cppreference.com/w/cpp/language/static_assert
/// [RFC 2790]: https://github.com/rust-lang/rfcs/issues/2790
///
/// # Examples
///
/// ```
/// static_assert!(42 > 24);
/// static_assert!(core::mem::size_of::<u8>() == 1);
///
/// const X: &[u8] = b"bar";
/// static_assert!(X[1] == b'a');
///
/// const fn f(x: i32) -> i32 {
/// x + 2
/// }
/// static_assert!(f(40) == 42);
/// ```
#[macro_export]
macro_rules! static_assert {
($condition:expr) => {
const _: () = core::assert!($condition);
};
}