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equals

typewit::const_marker

Function equals 

Source 
pub const fn equals<L, R>(_lhs: &L, _rhs: &R) -> TypeCmp<L, R>
where
    L: ConstMarkerEq,
    R: ConstMarkerEq<Of = L::Of>,
Available on crate feature rust_1_83 only.
Expand description

Compared any two ConstMarkerEq types that have constants of the same type, returning a proof of their type (in)equality.

ยงExample

use typewit::TypeCmp;
use typewit::const_marker::{self, ConstMarkerEq, Char, U8};
 
assert_eq!(typecast(Char::<' '>, Char::<' '>), Ok([Char::<' '>, Char::<' '>]));
assert_eq!(typecast(Char::<'X'>, Char::<'Y'>), Err((Char::<'X'>, Char::<'Y'>)));
 
assert_eq!(typecast(U8::<3>, U8::<3>), Ok([U8::<3>, U8::<3>]));
assert_eq!(typecast(U8::<5>, U8::<8>), Err((U8::<5>, U8::<8>)));
 
 
 
const fn typecast<L, R>(lhs: L, rhs: R) -> Result<[L; 2], (L, R)>
where
   L: ConstMarkerEq,
   R: ConstMarkerEq<Of = L::Of>,
{
    match const_marker::equals(&lhs, &rhs) {
        TypeCmp::Eq(te) => Ok([lhs, te.to_left(rhs)]),
        TypeCmp::Ne(_) => Err((lhs, rhs))
    }
}