rust-lang/rust
1
0
Fork 0
Code Issues Pull Requests Actions 1 Packages Projects Releases Wiki Activity

Coroutine closures implement regular Fn traits, when possible

Browse Source
This commit is contained in:
Michael Goulet
2024-02-05 19:59:05 +00:00
parent 08af64e96b
commit b8c93f1223
5 changed files with 142 additions and 18 deletions
Download Patch File Download Diff File Expand all files Collapse all files

25
compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs
View File

@@ -332,6 +332,31 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
}
}
}
ty::CoroutineClosure(def_id, args) => {
let is_const = self.tcx().is_const_fn_raw(def_id);
match self.infcx.closure_kind(self_ty) {
Some(closure_kind) => {
let no_borrows = self
.infcx
.shallow_resolve(args.as_coroutine_closure().tupled_upvars_ty())
.tuple_fields()
.is_empty();
if no_borrows && closure_kind.extends(kind) {
candidates.vec.push(ClosureCandidate { is_const });
} else if kind == ty::ClosureKind::FnOnce {
candidates.vec.push(ClosureCandidate { is_const });
}
}
None => {
if kind == ty::ClosureKind::FnOnce {
candidates.vec.push(ClosureCandidate { is_const });
} else {
// This stays ambiguous until kind+upvars are determined.
candidates.ambiguous = true;
}
}
}
}
ty::Infer(ty::TyVar(_)) => {
debug!("assemble_unboxed_closure_candidates: ambiguous self-type");
candidates.ambiguous = true;

26
compiler/rustc_trait_selection/src/traits/select/confirmation.rs
View File

@@ -865,17 +865,25 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
// touch bound regions, they just capture the in-scope
// type/region parameters.
let self_ty = self.infcx.shallow_resolve(obligation.self_ty().skip_binder());
let ty::Closure(closure_def_id, args) = *self_ty.kind() else {
bug!("closure candidate for non-closure {:?}", obligation);
let trait_ref = match *self_ty.kind() {
ty::Closure(_, args) => {
self.closure_trait_ref_unnormalized(obligation, args, self.tcx().consts.true_)
}
ty::CoroutineClosure(_, args) => {
args.as_coroutine_closure().coroutine_closure_sig().map_bound(|sig| {
ty::TraitRef::new(
self.tcx(),
obligation.predicate.def_id(),
[self_ty, sig.tupled_inputs_ty],
)
})
}
_ => {
bug!("closure candidate for non-closure {:?}", obligation);
}
};
let trait_ref =
self.closure_trait_ref_unnormalized(obligation, args, self.tcx().consts.true_);
let nested = self.confirm_poly_trait_refs(obligation, trait_ref)?;
debug!(?closure_def_id, ?trait_ref, ?nested, "confirm closure candidate obligations");
Ok(nested)
self.confirm_poly_trait_refs(obligation, trait_ref)
}
#[instrument(skip(self), level = "debug")]