bjoernager/rust
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Member constraints already covered all of E0482 already, so that error never occurred anymore

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This commit is contained in:
Oli Scherer 2021-10-16 13:54:08 +00:00
parent 2220fafa8c
commit 4413f8c709
4 changed files with 6 additions and 65 deletions
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41
compiler/rustc_trait_selection/src/opaque_types.rs
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@ -6,7 +6,7 @@ use rustc_hir::def_id::{DefId, LocalDefId};
use rustc_infer::infer::error_reporting::unexpected_hidden_region_diagnostic;
use rustc_infer::infer::opaque_types::OpaqueTypeDecl;
use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
use rustc_infer::infer::{self, InferCtxt, InferOk};
use rustc_infer::infer::{InferCtxt, InferOk};
use rustc_middle::ty::fold::{BottomUpFolder, TypeFoldable, TypeFolder, TypeVisitor};
use rustc_middle::ty::subst::{GenericArg, GenericArgKind, InternalSubsts, Subst};
use rustc_middle::ty::{self, OpaqueTypeKey, Ty, TyCtxt};
@ -295,36 +295,7 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
hir::OpaqueTyOrigin::TyAlias => 0,
};
let span = tcx.def_span(def_id);
// Check if the `impl Trait` bounds include region bounds.
// For example, this would be true for:
//
// fn foo<'a, 'b, 'c>() -> impl Trait<'c> + 'a + 'b
//
// but false for:
//
// fn foo<'c>() -> impl Trait<'c>
//
// unless `Trait` was declared like:
//
// trait Trait<'c>: 'c
//
// in which case it would be true.
//
// This is used during regionck to decide whether we need to
// impose any additional constraints to ensure that region
// variables in `concrete_ty` wind up being constrained to
// something from `substs` (or, at minimum, things that outlive
// the fn body). (Ultimately, writeback is responsible for this
// check.)
let bounds = tcx.explicit_item_bounds(def_id);
debug!("{:#?}", bounds);
let bounds = bounds.iter().map(|(bound, _)| bound.subst(tcx, opaque_type_key.substs));
debug!("{:#?}", bounds);
let opaque_type = tcx.mk_opaque(def_id, opaque_type_key.substs);
// (A) The regions that appear in the hidden type must be equal to
// The regions that appear in the hidden type must be equal to
// one of the regions in scope for the opaque type.
self.generate_member_constraint(
concrete_ty,
@ -332,14 +303,6 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
opaque_type_key,
first_own_region,
);
// (B) We can also generate outlives bounds that must be enforced.
for required_region in required_region_bounds(tcx, opaque_type, bounds) {
concrete_ty.visit_with(&mut ConstrainOpaqueTypeRegionVisitor {
tcx,
op: |r| self.sub_regions(infer::CallReturn(span), required_region, r),
});
}
}
/// As a fallback, we sometimes generate an "in constraint". For