} else {
relation.relate_with_variance(ty::Contravariant, a, b)
}
+ })
+ .enumerate()
+ .map(|(i, r)| match r {
+ Err(TypeError::Sorts(exp_found)) => Err(TypeError::ArgumentSorts(exp_found, i)),
+ Err(TypeError::Mutability) => Err(TypeError::ArgumentMutability(i)),
+ r => r,
});
Ok(ty::FnSig {
inputs_and_output: tcx.mk_type_list(inputs_and_output)?,