Auto merge of #116756 - fee1-dead-contrib:dupe-those-bounds, r=oli-obk

Duplicate `~const` bounds with a non-const one in effects desugaring

This should unblock #116058.

r? `@oli-obk`
This commit is contained in:
bors
2023-10-17 12:16:54 +00:00
10 changed files with 661 additions and 40 deletions

View File

@@ -1091,7 +1091,8 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
self.trait_defines_associated_item_named(r.def_id(), ty::AssocKind::Const, assoc_name)
});
let (bound, next_cand) = match (matching_candidates.next(), const_candidates.next()) {
let (mut bound, mut next_cand) = match (matching_candidates.next(), const_candidates.next())
{
(Some(bound), _) => (bound, matching_candidates.next()),
(None, Some(bound)) => (bound, const_candidates.next()),
(None, None) => {
@@ -1107,6 +1108,37 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
};
debug!(?bound);
// look for a candidate that is not the same as our first bound, disregarding
// whether the bound is const.
while let Some(mut bound2) = next_cand {
debug!(?bound2);
let tcx = self.tcx();
if bound2.bound_vars() != bound.bound_vars() {
break;
}
let generics = tcx.generics_of(bound.def_id());
let Some(host_index) = generics.host_effect_index else { break };
// always return the bound that contains the host param.
if let ty::ConstKind::Param(_) = bound2.skip_binder().args.const_at(host_index).kind() {
(bound, bound2) = (bound2, bound);
}
let unconsted_args = bound
.skip_binder()
.args
.iter()
.enumerate()
.map(|(n, arg)| if host_index == n { tcx.consts.true_.into() } else { arg });
if unconsted_args.eq(bound2.skip_binder().args.iter()) {
next_cand = matching_candidates.next().or_else(|| const_candidates.next());
} else {
break;
}
}
if let Some(bound2) = next_cand {
debug!(?bound2);