/// Polyfill for `Option::unwrap()` as a const fn; feature `const_option`.
/// https://github.com/rust-lang/rust/issues/67441.
/// TODO(MSRV): Replace this with `x.unwrap()`.
////// `T: Copy` avoids "constant functions cannot evaluate destructors."
pubconstfnunwrap_const<T>(x:Option<T>)-> T
where
T: Copy,
{ifletSome(x)= x {
x
}else{panic!("unwrap_const on `None`");}}