macro_rules! maybe_const_fn {
(
#[cfg($cfg_predicate:meta)]
$(#[$attr:meta])*
$vis:vis $(unsafe $($unsafe:lifetime)?)? fn $name:ident $($rest:tt)*
) => { ... };
}
Expand description
A macro for conditionally const-ifying a function.
#[allow(unused)] because currently it is only used with the must_cast
feature.