Macro mirai_annotations::assume_unreachable

macro_rules! assume_unreachable {
    () => { ... };
    ($message:literal) => { ... };
    ($msg:expr,) => { ... };
    ($fmt:expr, $($arg:tt)*) => { ... };
}

Equivalent to unreachable! when used with an unmodified Rust compiler. When compiled with MIRAI, this causes MIRAI to assume that the annotation statement cannot be reached.