// 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`]. /// /// An optional panic message can be supplied after the expression. /// Currently only a string literal without formatting is supported /// due to constness limitations of the [`assert!`] macro. /// /// 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); /// static_assert!(f(40) == 42, "f(x) must add 2 to the given input."); /// ``` #[macro_export] macro_rules! static_assert { ($condition:expr $(,$arg:literal)?) => { const _: () = ::core::assert!($condition $(,$arg)?); }; }