Macro kernel::build_error
source · macro_rules! build_error { () => { ... }; ($msg:expr) => { ... }; }
Expand description
Fails the build if the code path calling build_error!
can possibly be executed.
If the macro is executed in const context, build_error!
will panic.
If the compiler or optimizer cannot guarantee that build_error!
can never
be called, a build error will be triggered.
§Examples
#[inline]
fn foo(a: usize) -> usize {
a.checked_add(1).unwrap_or_else(|| build_error!("overflow"))
}
assert_eq!(foo(usize::MAX - 1), usize::MAX); // OK.
// foo(usize::MAX); // Fails to compile.