Macro unsafe_precondition_assert 

macro_rules! unsafe_precondition_assert {
    ($cond:expr $(,)?) => { ... };
    ($cond:expr, $($arg:tt)+) => { ... };
    (@inner $cond:expr, $msg:expr) => { ... };
}

Checks that a precondition of an unsafe function is followed.

The check is enabled at runtime if debug assertions (CONFIG_RUST_DEBUG_ASSERTIONS) are enabled. Otherwise, this macro is a no-op.

Examples

use kernel::unsafe_precondition_assert;

struct RawBuffer<T: Copy, const N: usize> {
    data: [T; N],
}

impl<T: Copy, const N: usize> RawBuffer<T, N> {
    /// # Safety
    ///
    /// The caller must ensure that `index` is less than `N`.
    unsafe fn set_unchecked(&mut self, index: usize, value: T) {
        unsafe_precondition_assert!(
            index < N,
            "RawBuffer::set_unchecked() requires index ({index}) < N ({N})"
        );

        // SAFETY: By the safety requirements of this function, `index` is valid.
        unsafe {
            *self.data.get_unchecked_mut(index) = value;
        }
    }
}

Panics

Panics if the expression is evaluated to false at runtime.