From e4c1a0016c0bd1b6579123c785e38e63b4ccf143 Mon Sep 17 00:00:00 2001 From: Michael Goulet Date: Fri, 8 Nov 2024 03:46:23 +0000 Subject: [PATCH] Get rid of check_opaque_type_well_formed --- .../src/region_infer/opaque_types.rs | 90 +------------ .../rustc_hir_analysis/src/check/check.rs | 122 +++++++++++++++--- .../async-await/issue-70935-complex-spans.rs | 2 +- .../issue-70935-complex-spans.stderr | 16 ++- tests/ui/pattern/usefulness/impl-trait.stderr | 56 ++++---- .../closure_wf_outlives.rs | 6 +- .../closure_wf_outlives.stderr | 38 +++--- .../generic_duplicate_param_use3.rs | 3 +- .../generic_duplicate_param_use3.stderr | 29 ++--- .../generic_duplicate_param_use5.rs | 5 +- .../generic_duplicate_param_use5.stderr | 55 ++------ .../generic_duplicate_param_use6.rs | 4 +- .../generic_duplicate_param_use6.stderr | 43 ++---- .../generic_duplicate_param_use8.rs | 3 +- .../generic_duplicate_param_use8.stderr | 31 ++--- .../generic_duplicate_param_use9.rs | 6 +- .../generic_duplicate_param_use9.stderr | 64 ++------- .../implied_lifetime_wf_check4_static.rs | 2 +- .../implied_lifetime_wf_check4_static.stderr | 12 +- .../not_a_defining_use.rs | 4 +- .../not_a_defining_use.stderr | 42 ++---- .../underconstrained_lifetime.rs | 2 +- .../underconstrained_lifetime.stderr | 6 +- .../wf-in-associated-type.fail.stderr | 14 +- .../wf-in-associated-type.rs | 4 +- 25 files changed, 247 insertions(+), 412 deletions(-) diff --git a/compiler/rustc_borrowck/src/region_infer/opaque_types.rs b/compiler/rustc_borrowck/src/region_infer/opaque_types.rs index f9dd649ab9f..d676ce59cfe 100644 --- a/compiler/rustc_borrowck/src/region_infer/opaque_types.rs +++ b/compiler/rustc_borrowck/src/region_infer/opaque_types.rs @@ -1,10 +1,7 @@ use rustc_data_structures::fx::FxIndexMap; use rustc_errors::ErrorGuaranteed; -use rustc_hir::OpaqueTyOrigin; -use rustc_hir::def::DefKind; use rustc_hir::def_id::LocalDefId; use rustc_infer::infer::{InferCtxt, NllRegionVariableOrigin, TyCtxtInferExt as _}; -use rustc_infer::traits::{Obligation, ObligationCause}; use rustc_macros::extension; use rustc_middle::ty::visit::TypeVisitableExt; use rustc_middle::ty::{ @@ -12,7 +9,6 @@ TypingMode, }; use rustc_span::Span; -use rustc_trait_selection::error_reporting::InferCtxtErrorExt; use rustc_trait_selection::traits::ObligationCtxt; use tracing::{debug, instrument}; @@ -303,91 +299,7 @@ fn infer_opaque_definition_from_instantiation( return Ty::new_error(self.tcx, e); } - // `definition_ty` does not live in of the current inference context, - // so lets make sure that we don't accidentally misuse our current `infcx`. - match check_opaque_type_well_formed( - self.tcx, - self.next_trait_solver(), - opaque_type_key.def_id, - instantiated_ty.span, - definition_ty, - ) { - Ok(hidden_ty) => hidden_ty, - Err(guar) => Ty::new_error(self.tcx, guar), - } - } -} - -/// This logic duplicates most of `check_opaque_meets_bounds`. -/// FIXME(oli-obk): Also do region checks here and then consider removing -/// `check_opaque_meets_bounds` entirely. -fn check_opaque_type_well_formed<'tcx>( - tcx: TyCtxt<'tcx>, - next_trait_solver: bool, - def_id: LocalDefId, - definition_span: Span, - definition_ty: Ty<'tcx>, -) -> Result, ErrorGuaranteed> { - // Only check this for TAIT. RPIT already supports `tests/ui/impl-trait/nested-return-type2.rs` - // on stable and we'd break that. - let opaque_ty_hir = tcx.hir().expect_opaque_ty(def_id); - let OpaqueTyOrigin::TyAlias { .. } = opaque_ty_hir.origin else { - return Ok(definition_ty); - }; - let param_env = tcx.param_env(def_id); - - let mut parent_def_id = def_id; - while tcx.def_kind(parent_def_id) == DefKind::OpaqueTy { - parent_def_id = tcx.local_parent(parent_def_id); - } - - // FIXME(#132279): This should eventually use the already defined hidden types - // instead. Alternatively we'll entirely remove this function given we also check - // the opaque in `check_opaque_meets_bounds` later. - let infcx = tcx - .infer_ctxt() - .with_next_trait_solver(next_trait_solver) - .build(TypingMode::analysis_in_body(tcx, parent_def_id)); - let ocx = ObligationCtxt::new_with_diagnostics(&infcx); - let identity_args = GenericArgs::identity_for_item(tcx, def_id); - - // Require that the hidden type actually fulfills all the bounds of the opaque type, even without - // the bounds that the function supplies. - let opaque_ty = Ty::new_opaque(tcx, def_id.to_def_id(), identity_args); - ocx.eq(&ObligationCause::misc(definition_span, def_id), param_env, opaque_ty, definition_ty) - .map_err(|err| { - infcx - .err_ctxt() - .report_mismatched_types( - &ObligationCause::misc(definition_span, def_id), - param_env, - opaque_ty, - definition_ty, - err, - ) - .emit() - })?; - - // Require the hidden type to be well-formed with only the generics of the opaque type. - // Defining use functions may have more bounds than the opaque type, which is ok, as long as the - // hidden type is well formed even without those bounds. - let predicate = ty::Binder::dummy(ty::PredicateKind::Clause(ty::ClauseKind::WellFormed( - definition_ty.into(), - ))); - ocx.register_obligation(Obligation::misc(tcx, definition_span, def_id, param_env, predicate)); - - // Check that all obligations are satisfied by the implementation's - // version. - let errors = ocx.select_all_or_error(); - - // This is fishy, but we check it again in `check_opaque_meets_bounds`. - // Remove once we can prepopulate with known hidden types. - let _ = infcx.take_opaque_types(); - - if errors.is_empty() { - Ok(definition_ty) - } else { - Err(infcx.err_ctxt().report_fulfillment_errors(errors)) + definition_ty } } diff --git a/compiler/rustc_hir_analysis/src/check/check.rs b/compiler/rustc_hir_analysis/src/check/check.rs index 50ea8018e76..12b842e70b7 100644 --- a/compiler/rustc_hir_analysis/src/check/check.rs +++ b/compiler/rustc_hir_analysis/src/check/check.rs @@ -5,13 +5,14 @@ use rustc_data_structures::unord::{UnordMap, UnordSet}; use rustc_errors::MultiSpan; use rustc_errors::codes::*; -use rustc_hir::Node; use rustc_hir::def::{CtorKind, DefKind}; +use rustc_hir::{Node, intravisit}; use rustc_infer::infer::{RegionVariableOrigin, TyCtxtInferExt}; use rustc_infer::traits::Obligation; use rustc_lint_defs::builtin::{ REPR_TRANSPARENT_EXTERNAL_PRIVATE_FIELDS, UNSUPPORTED_FN_PTR_CALLING_CONVENTIONS, }; +use rustc_middle::hir::nested_filter; use rustc_middle::middle::resolve_bound_vars::ResolvedArg; use rustc_middle::middle::stability::EvalResult; use rustc_middle::span_bug; @@ -190,7 +191,7 @@ fn check_static_inhabited(tcx: TyCtxt<'_>, def_id: LocalDefId) { /// Checks that an opaque type does not contain cycles and does not use `Self` or `T::Foo` /// projections that would result in "inheriting lifetimes". fn check_opaque(tcx: TyCtxt<'_>, def_id: LocalDefId) { - let hir::OpaqueTy { origin, .. } = tcx.hir().expect_opaque_ty(def_id); + let hir::OpaqueTy { origin, .. } = *tcx.hir().expect_opaque_ty(def_id); // HACK(jynelson): trying to infer the type of `impl trait` breaks documenting // `async-std` (and `pub async fn` in general). @@ -200,23 +201,20 @@ fn check_opaque(tcx: TyCtxt<'_>, def_id: LocalDefId) { return; } - let span = tcx.def_span(def_id); - if tcx.type_of(def_id).instantiate_identity().references_error() { return; } - if check_opaque_for_cycles(tcx, def_id, span).is_err() { + if check_opaque_for_cycles(tcx, def_id).is_err() { return; } - let _ = check_opaque_meets_bounds(tcx, def_id, span, origin); + let _ = check_opaque_meets_bounds(tcx, def_id, origin); } /// Checks that an opaque type does not contain cycles. pub(super) fn check_opaque_for_cycles<'tcx>( tcx: TyCtxt<'tcx>, def_id: LocalDefId, - span: Span, ) -> Result<(), ErrorGuaranteed> { let args = GenericArgs::identity_for_item(tcx, def_id); @@ -233,7 +231,7 @@ pub(super) fn check_opaque_for_cycles<'tcx>( .try_expand_impl_trait_type(def_id.to_def_id(), args, InspectCoroutineFields::No) .is_err() { - let reported = opaque_type_cycle_error(tcx, def_id, span); + let reported = opaque_type_cycle_error(tcx, def_id); return Err(reported); } @@ -267,10 +265,11 @@ pub(super) fn check_opaque_for_cycles<'tcx>( fn check_opaque_meets_bounds<'tcx>( tcx: TyCtxt<'tcx>, def_id: LocalDefId, - span: Span, - origin: &hir::OpaqueTyOrigin, + origin: hir::OpaqueTyOrigin, ) -> Result<(), ErrorGuaranteed> { - let defining_use_anchor = match *origin { + let span = span_of_opaque(tcx, def_id, origin).unwrap_or_else(|| tcx.def_span(def_id)); + + let defining_use_anchor = match origin { hir::OpaqueTyOrigin::FnReturn { parent, .. } | hir::OpaqueTyOrigin::AsyncFn { parent, .. } | hir::OpaqueTyOrigin::TyAlias { parent, .. } => parent, @@ -281,7 +280,7 @@ fn check_opaque_meets_bounds<'tcx>( let infcx = tcx.infer_ctxt().build(TypingMode::analysis_in_body(tcx, defining_use_anchor)); let ocx = ObligationCtxt::new_with_diagnostics(&infcx); - let args = match *origin { + let args = match origin { hir::OpaqueTyOrigin::FnReturn { parent, .. } | hir::OpaqueTyOrigin::AsyncFn { parent, .. } | hir::OpaqueTyOrigin::TyAlias { parent, .. } => GenericArgs::identity_for_item( @@ -308,6 +307,7 @@ fn check_opaque_meets_bounds<'tcx>( let misc_cause = traits::ObligationCause::misc(span, def_id); + // FIXME: We should just register the item bounds here, rather than equating. match ocx.eq(&misc_cause, param_env, opaque_ty, hidden_ty) { Ok(()) => {} Err(ty_err) => { @@ -364,6 +364,97 @@ fn check_opaque_meets_bounds<'tcx>( } } +fn span_of_opaque<'tcx>( + tcx: TyCtxt<'tcx>, + opaque_def_id: LocalDefId, + origin: hir::OpaqueTyOrigin, +) -> Option { + struct TaitConstraintLocator<'tcx> { + opaque_def_id: LocalDefId, + tcx: TyCtxt<'tcx>, + } + impl<'tcx> TaitConstraintLocator<'tcx> { + fn check(&self, item_def_id: LocalDefId) -> ControlFlow { + if !self.tcx.has_typeck_results(item_def_id) { + return ControlFlow::Continue(()); + } + + if let Some(hidden_ty) = + self.tcx.mir_borrowck(item_def_id).concrete_opaque_types.get(&self.opaque_def_id) + { + ControlFlow::Break(hidden_ty.span) + } else { + ControlFlow::Continue(()) + } + } + } + impl<'tcx> intravisit::Visitor<'tcx> for TaitConstraintLocator<'tcx> { + type NestedFilter = nested_filter::All; + type Result = ControlFlow; + fn nested_visit_map(&mut self) -> Self::Map { + self.tcx.hir() + } + fn visit_expr(&mut self, ex: &'tcx hir::Expr<'tcx>) -> Self::Result { + if let hir::ExprKind::Closure(closure) = ex.kind { + self.check(closure.def_id)?; + } + intravisit::walk_expr(self, ex) + } + fn visit_item(&mut self, it: &'tcx hir::Item<'tcx>) -> Self::Result { + self.check(it.owner_id.def_id)?; + intravisit::walk_item(self, it) + } + fn visit_impl_item(&mut self, it: &'tcx hir::ImplItem<'tcx>) -> Self::Result { + self.check(it.owner_id.def_id)?; + intravisit::walk_impl_item(self, it) + } + fn visit_trait_item(&mut self, it: &'tcx hir::TraitItem<'tcx>) -> Self::Result { + self.check(it.owner_id.def_id)?; + intravisit::walk_trait_item(self, it) + } + fn visit_foreign_item(&mut self, it: &'tcx hir::ForeignItem<'tcx>) -> Self::Result { + intravisit::walk_foreign_item(self, it) + } + } + + let mut locator = TaitConstraintLocator { tcx, opaque_def_id }; + match origin { + hir::OpaqueTyOrigin::FnReturn { parent, .. } + | hir::OpaqueTyOrigin::AsyncFn { parent, .. } => locator.check(parent).break_value(), + hir::OpaqueTyOrigin::TyAlias { parent, in_assoc_ty: true } => { + let impl_def_id = tcx.local_parent(parent); + for assoc in tcx.associated_items(impl_def_id).in_definition_order() { + match assoc.kind { + ty::AssocKind::Const | ty::AssocKind::Fn => { + if let ControlFlow::Break(span) = locator.check(assoc.def_id.expect_local()) + { + return Some(span); + } + } + ty::AssocKind::Type => {} + } + } + + None + } + hir::OpaqueTyOrigin::TyAlias { in_assoc_ty: false, .. } => { + let scope = tcx.hir().get_defining_scope(tcx.local_def_id_to_hir_id(opaque_def_id)); + let found = if scope == hir::CRATE_HIR_ID { + tcx.hir().walk_toplevel_module(&mut locator) + } else { + match tcx.hir_node(scope) { + Node::Item(it) => locator.visit_item(it), + Node::ImplItem(it) => locator.visit_impl_item(it), + Node::TraitItem(it) => locator.visit_trait_item(it), + Node::ForeignItem(it) => locator.visit_foreign_item(it), + other => bug!("{:?} is not a valid scope for an opaque type item", other), + } + }; + found.break_value() + } + } +} + fn sanity_check_found_hidden_type<'tcx>( tcx: TyCtxt<'tcx>, key: ty::OpaqueTypeKey<'tcx>, @@ -1535,11 +1626,8 @@ fn check_type_alias_type_params_are_used<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalD /// /// If all the return expressions evaluate to `!`, then we explain that the error will go away /// after changing it. This can happen when a user uses `panic!()` or similar as a placeholder. -fn opaque_type_cycle_error( - tcx: TyCtxt<'_>, - opaque_def_id: LocalDefId, - span: Span, -) -> ErrorGuaranteed { +fn opaque_type_cycle_error(tcx: TyCtxt<'_>, opaque_def_id: LocalDefId) -> ErrorGuaranteed { + let span = tcx.def_span(opaque_def_id); let mut err = struct_span_code_err!(tcx.dcx(), span, E0720, "cannot resolve opaque type"); let mut label = false; diff --git a/tests/ui/async-await/issue-70935-complex-spans.rs b/tests/ui/async-await/issue-70935-complex-spans.rs index a74bd9890ca..2851637ae78 100644 --- a/tests/ui/async-await/issue-70935-complex-spans.rs +++ b/tests/ui/async-await/issue-70935-complex-spans.rs @@ -14,8 +14,8 @@ async fn baz(_c: impl FnMut() -> T) where T: Future { fn foo(x: NotSync) -> impl Future + Send { //~^ ERROR `*mut ()` cannot be shared between threads safely - //~| ERROR `*mut ()` cannot be shared between threads safely async move { + //~^ ERROR `*mut ()` cannot be shared between threads safely baz(|| async { foo(x.clone()); }).await; diff --git a/tests/ui/async-await/issue-70935-complex-spans.stderr b/tests/ui/async-await/issue-70935-complex-spans.stderr index c6b7e21b9dd..777eefe897b 100644 --- a/tests/ui/async-await/issue-70935-complex-spans.stderr +++ b/tests/ui/async-await/issue-70935-complex-spans.stderr @@ -1,8 +1,13 @@ error[E0277]: `*mut ()` cannot be shared between threads safely - --> $DIR/issue-70935-complex-spans.rs:15:23 + --> $DIR/issue-70935-complex-spans.rs:17:5 | -LL | fn foo(x: NotSync) -> impl Future + Send { - | ^^^^^^^^^^^^^^^^^^ `*mut ()` cannot be shared between threads safely +LL | / async move { +LL | | +LL | | baz(|| async { +LL | | foo(x.clone()); +LL | | }).await; +LL | | } + | |_____^ `*mut ()` cannot be shared between threads safely | = help: within `NotSync`, the trait `Sync` is not implemented for `*mut ()` note: required because it appears within the type `PhantomData<*mut ()>` @@ -26,7 +31,7 @@ LL | async fn baz(_c: impl FnMut() -> T) where T: Future { LL | | } | |_^ note: required because it's used within this `async` block - --> $DIR/issue-70935-complex-spans.rs:18:5 + --> $DIR/issue-70935-complex-spans.rs:17:5 | LL | async move { | ^^^^^^^^^^ @@ -59,11 +64,10 @@ LL | async fn baz(_c: impl FnMut() -> T) where T: Future { LL | | } | |_^ note: required because it's used within this `async` block - --> $DIR/issue-70935-complex-spans.rs:18:5 + --> $DIR/issue-70935-complex-spans.rs:17:5 | LL | async move { | ^^^^^^^^^^ - = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no` error: aborting due to 2 previous errors diff --git a/tests/ui/pattern/usefulness/impl-trait.stderr b/tests/ui/pattern/usefulness/impl-trait.stderr index 75cba4b5f02..34f8eb1e163 100644 --- a/tests/ui/pattern/usefulness/impl-trait.stderr +++ b/tests/ui/pattern/usefulness/impl-trait.stderr @@ -25,6 +25,20 @@ LL | _ => {} | = note: to learn more about uninhabited types, see https://doc.rust-lang.org/nomicon/exotic-sizes.html#empty-types +error[E0004]: non-exhaustive patterns: type `impl Copy` is non-empty + --> $DIR/impl-trait.rs:23:11 + | +LL | match return_never_rpit(x) {} + | ^^^^^^^^^^^^^^^^^^^^ + | + = note: the matched value is of type `impl Copy` +help: ensure that all possible cases are being handled by adding a match arm with a wildcard pattern as shown + | +LL ~ match return_never_rpit(x) { +LL + _ => todo!(), +LL + } + | + error: unreachable pattern --> $DIR/impl-trait.rs:45:13 | @@ -93,6 +107,20 @@ LL | _ => {} | = note: to learn more about uninhabited types, see https://doc.rust-lang.org/nomicon/exotic-sizes.html#empty-types +error[E0004]: non-exhaustive patterns: type `T` is non-empty + --> $DIR/impl-trait.rs:37:11 + | +LL | match return_never_tait(x) {} + | ^^^^^^^^^^^^^^^^^^^^ + | + = note: the matched value is of type `T` +help: ensure that all possible cases are being handled by adding a match arm with a wildcard pattern as shown + | +LL ~ match return_never_tait(x) { +LL + _ => todo!(), +LL + } + | + error: unreachable pattern --> $DIR/impl-trait.rs:105:9 | @@ -131,34 +159,6 @@ LL | _ => {} | = note: to learn more about uninhabited types, see https://doc.rust-lang.org/nomicon/exotic-sizes.html#empty-types -error[E0004]: non-exhaustive patterns: type `impl Copy` is non-empty - --> $DIR/impl-trait.rs:23:11 - | -LL | match return_never_rpit(x) {} - | ^^^^^^^^^^^^^^^^^^^^ - | - = note: the matched value is of type `impl Copy` -help: ensure that all possible cases are being handled by adding a match arm with a wildcard pattern as shown - | -LL ~ match return_never_rpit(x) { -LL + _ => todo!(), -LL + } - | - -error[E0004]: non-exhaustive patterns: type `T` is non-empty - --> $DIR/impl-trait.rs:37:11 - | -LL | match return_never_tait(x) {} - | ^^^^^^^^^^^^^^^^^^^^ - | - = note: the matched value is of type `T` -help: ensure that all possible cases are being handled by adding a match arm with a wildcard pattern as shown - | -LL ~ match return_never_tait(x) { -LL + _ => todo!(), -LL + } - | - error: aborting due to 15 previous errors For more information about this error, try `rustc --explain E0004`. diff --git a/tests/ui/type-alias-impl-trait/closure_wf_outlives.rs b/tests/ui/type-alias-impl-trait/closure_wf_outlives.rs index 430b444aae1..caa9b6d979a 100644 --- a/tests/ui/type-alias-impl-trait/closure_wf_outlives.rs +++ b/tests/ui/type-alias-impl-trait/closure_wf_outlives.rs @@ -12,20 +12,19 @@ // requires `'a: 'b` bound mod test1 { type Opaque<'a, 'b> = impl Sized + 'a + 'b; - //~^ ERROR lifetime bound not satisfied fn define<'a, 'b>() -> Opaque<'a, 'b> where 'a: 'b, { || {} + //~^ ERROR lifetime bound not satisfied } } // Same as the above but through indirection `'x` mod test2 { type Opaque<'a, 'b> = impl Sized + 'a + 'b; - //~^ ERROR cannot infer an appropriate lifetime fn define<'a, 'b, 'x>() -> Opaque<'a, 'b> where @@ -33,6 +32,7 @@ fn define<'a, 'b, 'x>() -> Opaque<'a, 'b> 'x: 'b, { || {} + //~^ ERROR cannot infer an appropriate lifetime } } @@ -52,13 +52,13 @@ fn define<'a, 'b, 'x>() -> Opaque<'a, 'b> // requires `T: 'static` mod test3 { type Opaque = impl Sized; - //~^ ERROR the parameter type `T` may not live long enough fn define() -> Opaque where T: 'static, { || {} + //~^ ERROR the parameter type `T` may not live long enough } } diff --git a/tests/ui/type-alias-impl-trait/closure_wf_outlives.stderr b/tests/ui/type-alias-impl-trait/closure_wf_outlives.stderr index 3484485e3fd..04288112fa8 100644 --- a/tests/ui/type-alias-impl-trait/closure_wf_outlives.stderr +++ b/tests/ui/type-alias-impl-trait/closure_wf_outlives.stderr @@ -1,8 +1,8 @@ error[E0478]: lifetime bound not satisfied - --> $DIR/closure_wf_outlives.rs:14:27 + --> $DIR/closure_wf_outlives.rs:20:9 | -LL | type Opaque<'a, 'b> = impl Sized + 'a + 'b; - | ^^^^^^^^^^^^^^^^^^^^ +LL | || {} + | ^^^^^ | note: lifetime parameter instantiated with the lifetime `'a` as defined here --> $DIR/closure_wf_outlives.rs:14:17 @@ -16,10 +16,10 @@ LL | type Opaque<'a, 'b> = impl Sized + 'a + 'b; | ^^ error[E0495]: cannot infer an appropriate lifetime due to conflicting requirements - --> $DIR/closure_wf_outlives.rs:27:27 + --> $DIR/closure_wf_outlives.rs:34:9 | -LL | type Opaque<'a, 'b> = impl Sized + 'a + 'b; - | ^^^^^^^^^^^^^^^^^^^^ +LL | || {} + | ^^^^^ | note: first, the lifetime cannot outlive the lifetime `'a` as defined here... --> $DIR/closure_wf_outlives.rs:27:17 @@ -27,32 +27,32 @@ note: first, the lifetime cannot outlive the lifetime `'a` as defined here... LL | type Opaque<'a, 'b> = impl Sized + 'a + 'b; | ^^ note: ...so that the declared lifetime parameter bounds are satisfied - --> $DIR/closure_wf_outlives.rs:27:27 + --> $DIR/closure_wf_outlives.rs:34:9 | -LL | type Opaque<'a, 'b> = impl Sized + 'a + 'b; - | ^^^^^^^^^^^^^^^^^^^^ +LL | || {} + | ^^^^^ note: but, the lifetime must be valid for the lifetime `'b` as defined here... --> $DIR/closure_wf_outlives.rs:27:21 | LL | type Opaque<'a, 'b> = impl Sized + 'a + 'b; | ^^ note: ...so that the declared lifetime parameter bounds are satisfied - --> $DIR/closure_wf_outlives.rs:27:27 + --> $DIR/closure_wf_outlives.rs:34:9 | -LL | type Opaque<'a, 'b> = impl Sized + 'a + 'b; - | ^^^^^^^^^^^^^^^^^^^^ +LL | || {} + | ^^^^^ error[E0310]: the parameter type `T` may not live long enough - --> $DIR/closure_wf_outlives.rs:54:22 + --> $DIR/closure_wf_outlives.rs:60:9 | -LL | type Opaque = impl Sized; - | ^^^^^^^^^^ - | | - | the parameter type `T` must be valid for the static lifetime... - | ...so that the type `T` will meet its required lifetime bounds... +LL | || {} + | ^^^^^ + | | + | the parameter type `T` must be valid for the static lifetime... + | ...so that the type `T` will meet its required lifetime bounds... | note: ...that is required by this bound - --> $DIR/closure_wf_outlives.rs:59:12 + --> $DIR/closure_wf_outlives.rs:58:12 | LL | T: 'static, | ^^^^^^^ diff --git a/tests/ui/type-alias-impl-trait/generic_duplicate_param_use3.rs b/tests/ui/type-alias-impl-trait/generic_duplicate_param_use3.rs index e7a25fc7240..2074f12750f 100644 --- a/tests/ui/type-alias-impl-trait/generic_duplicate_param_use3.rs +++ b/tests/ui/type-alias-impl-trait/generic_duplicate_param_use3.rs @@ -9,10 +9,9 @@ fn main() {} fn two(t: T, _: U) -> Two { t - //~^ ERROR `T` doesn't implement `Debug` } fn three(_: T, u: U) -> Two { u - //~^ ERROR `U` doesn't implement `Debug` + //~^ ERROR concrete type differs } diff --git a/tests/ui/type-alias-impl-trait/generic_duplicate_param_use3.stderr b/tests/ui/type-alias-impl-trait/generic_duplicate_param_use3.stderr index 7bec3822071..9a10a4980d8 100644 --- a/tests/ui/type-alias-impl-trait/generic_duplicate_param_use3.stderr +++ b/tests/ui/type-alias-impl-trait/generic_duplicate_param_use3.stderr @@ -1,25 +1,14 @@ -error[E0277]: `T` doesn't implement `Debug` +error: concrete type differs from previous defining opaque type use + --> $DIR/generic_duplicate_param_use3.rs:15:5 + | +LL | u + | ^ expected `T`, got `U` + | +note: previous use here --> $DIR/generic_duplicate_param_use3.rs:11:5 | LL | t - | ^ `T` cannot be formatted using `{:?}` because it doesn't implement `Debug` - | -help: consider restricting type parameter `T` - | -LL | type Two = impl Debug; - | +++++++++++++++++ + | ^ -error[E0277]: `U` doesn't implement `Debug` - --> $DIR/generic_duplicate_param_use3.rs:16:5 - | -LL | u - | ^ `U` cannot be formatted using `{:?}` because it doesn't implement `Debug` - | -help: consider restricting type parameter `U` - | -LL | type Two = impl Debug; - | +++++++++++++++++ +error: aborting due to 1 previous error -error: aborting due to 2 previous errors - -For more information about this error, try `rustc --explain E0277`. diff --git a/tests/ui/type-alias-impl-trait/generic_duplicate_param_use5.rs b/tests/ui/type-alias-impl-trait/generic_duplicate_param_use5.rs index 3bd1dda6331..b3d6beaf848 100644 --- a/tests/ui/type-alias-impl-trait/generic_duplicate_param_use5.rs +++ b/tests/ui/type-alias-impl-trait/generic_duplicate_param_use5.rs @@ -9,12 +9,9 @@ fn main() {} fn two(t: T, u: U) -> Two { (t, u) - //~^ ERROR `T` doesn't implement `Debug` - //~| ERROR `U` doesn't implement `Debug` } fn three(t: T, u: U) -> Two { (u, t) - //~^ ERROR `T` doesn't implement `Debug` - //~| ERROR `U` doesn't implement `Debug` + //~^ ERROR concrete type differs } diff --git a/tests/ui/type-alias-impl-trait/generic_duplicate_param_use5.stderr b/tests/ui/type-alias-impl-trait/generic_duplicate_param_use5.stderr index 586ea82342a..b0027f8fa57 100644 --- a/tests/ui/type-alias-impl-trait/generic_duplicate_param_use5.stderr +++ b/tests/ui/type-alias-impl-trait/generic_duplicate_param_use5.stderr @@ -1,51 +1,14 @@ -error[E0277]: `T` doesn't implement `Debug` +error: concrete type differs from previous defining opaque type use + --> $DIR/generic_duplicate_param_use5.rs:15:5 + | +LL | (u, t) + | ^^^^^^ expected `(T, U)`, got `(U, T)` + | +note: previous use here --> $DIR/generic_duplicate_param_use5.rs:11:5 | LL | (t, u) - | ^^^^^^ `T` cannot be formatted using `{:?}` because it doesn't implement `Debug` - | - = note: required for `(T, U)` to implement `Debug` -help: consider restricting type parameter `T` - | -LL | type Two = impl Debug; - | +++++++++++++++++ + | ^^^^^^ -error[E0277]: `U` doesn't implement `Debug` - --> $DIR/generic_duplicate_param_use5.rs:11:5 - | -LL | (t, u) - | ^^^^^^ `U` cannot be formatted using `{:?}` because it doesn't implement `Debug` - | - = note: required for `(T, U)` to implement `Debug` -help: consider restricting type parameter `U` - | -LL | type Two = impl Debug; - | +++++++++++++++++ +error: aborting due to 1 previous error -error[E0277]: `U` doesn't implement `Debug` - --> $DIR/generic_duplicate_param_use5.rs:17:5 - | -LL | (u, t) - | ^^^^^^ `U` cannot be formatted using `{:?}` because it doesn't implement `Debug` - | - = note: required for `(U, T)` to implement `Debug` -help: consider restricting type parameter `U` - | -LL | type Two = impl Debug; - | +++++++++++++++++ - -error[E0277]: `T` doesn't implement `Debug` - --> $DIR/generic_duplicate_param_use5.rs:17:5 - | -LL | (u, t) - | ^^^^^^ `T` cannot be formatted using `{:?}` because it doesn't implement `Debug` - | - = note: required for `(U, T)` to implement `Debug` -help: consider restricting type parameter `T` - | -LL | type Two = impl Debug; - | +++++++++++++++++ - -error: aborting due to 4 previous errors - -For more information about this error, try `rustc --explain E0277`. diff --git a/tests/ui/type-alias-impl-trait/generic_duplicate_param_use6.rs b/tests/ui/type-alias-impl-trait/generic_duplicate_param_use6.rs index 5120925e5a4..fa8b2a290b9 100644 --- a/tests/ui/type-alias-impl-trait/generic_duplicate_param_use6.rs +++ b/tests/ui/type-alias-impl-trait/generic_duplicate_param_use6.rs @@ -9,11 +9,9 @@ fn main() {} fn two(t: T, u: U) -> Two { (t, t) - //~^ ERROR `T` doesn't implement `Debug` } fn three(t: T, u: U) -> Two { (u, t) - //~^ ERROR `T` doesn't implement `Debug` - //~| ERROR `U` doesn't implement `Debug` + //~^ ERROR concrete type differs } diff --git a/tests/ui/type-alias-impl-trait/generic_duplicate_param_use6.stderr b/tests/ui/type-alias-impl-trait/generic_duplicate_param_use6.stderr index cb162d382b6..09c01932cef 100644 --- a/tests/ui/type-alias-impl-trait/generic_duplicate_param_use6.stderr +++ b/tests/ui/type-alias-impl-trait/generic_duplicate_param_use6.stderr @@ -1,39 +1,14 @@ -error[E0277]: `T` doesn't implement `Debug` +error: concrete type differs from previous defining opaque type use + --> $DIR/generic_duplicate_param_use6.rs:15:5 + | +LL | (u, t) + | ^^^^^^ expected `(T, T)`, got `(U, T)` + | +note: previous use here --> $DIR/generic_duplicate_param_use6.rs:11:5 | LL | (t, t) - | ^^^^^^ `T` cannot be formatted using `{:?}` because it doesn't implement `Debug` - | - = note: required for `(T, T)` to implement `Debug` -help: consider restricting type parameter `T` - | -LL | type Two = impl Debug; - | +++++++++++++++++ + | ^^^^^^ -error[E0277]: `U` doesn't implement `Debug` - --> $DIR/generic_duplicate_param_use6.rs:16:5 - | -LL | (u, t) - | ^^^^^^ `U` cannot be formatted using `{:?}` because it doesn't implement `Debug` - | - = note: required for `(U, T)` to implement `Debug` -help: consider restricting type parameter `U` - | -LL | type Two = impl Debug; - | +++++++++++++++++ +error: aborting due to 1 previous error -error[E0277]: `T` doesn't implement `Debug` - --> $DIR/generic_duplicate_param_use6.rs:16:5 - | -LL | (u, t) - | ^^^^^^ `T` cannot be formatted using `{:?}` because it doesn't implement `Debug` - | - = note: required for `(U, T)` to implement `Debug` -help: consider restricting type parameter `T` - | -LL | type Two = impl Debug; - | +++++++++++++++++ - -error: aborting due to 3 previous errors - -For more information about this error, try `rustc --explain E0277`. diff --git a/tests/ui/type-alias-impl-trait/generic_duplicate_param_use8.rs b/tests/ui/type-alias-impl-trait/generic_duplicate_param_use8.rs index 3a4b5047b41..76c13bb027b 100644 --- a/tests/ui/type-alias-impl-trait/generic_duplicate_param_use8.rs +++ b/tests/ui/type-alias-impl-trait/generic_duplicate_param_use8.rs @@ -8,10 +8,9 @@ fn main() {} fn two(t: T, _: U) -> Two { (t, 4u32) - //~^ ERROR `T` doesn't implement `Debug` } fn three(_: T, u: U) -> Two { (u, 4u32) - //~^ ERROR `U` doesn't implement `Debug` + //~^ concrete type differs } diff --git a/tests/ui/type-alias-impl-trait/generic_duplicate_param_use8.stderr b/tests/ui/type-alias-impl-trait/generic_duplicate_param_use8.stderr index 14cbfb3806f..09d2abe3663 100644 --- a/tests/ui/type-alias-impl-trait/generic_duplicate_param_use8.stderr +++ b/tests/ui/type-alias-impl-trait/generic_duplicate_param_use8.stderr @@ -1,27 +1,14 @@ -error[E0277]: `T` doesn't implement `Debug` +error: concrete type differs from previous defining opaque type use + --> $DIR/generic_duplicate_param_use8.rs:14:5 + | +LL | (u, 4u32) + | ^^^^^^^^^ expected `(T, u32)`, got `(U, u32)` + | +note: previous use here --> $DIR/generic_duplicate_param_use8.rs:10:5 | LL | (t, 4u32) - | ^^^^^^^^^ `T` cannot be formatted using `{:?}` because it doesn't implement `Debug` - | - = note: required for `(T, u32)` to implement `Debug` -help: consider restricting type parameter `T` - | -LL | type Two = impl Debug; - | +++++++++++++++++ + | ^^^^^^^^^ -error[E0277]: `U` doesn't implement `Debug` - --> $DIR/generic_duplicate_param_use8.rs:15:5 - | -LL | (u, 4u32) - | ^^^^^^^^^ `U` cannot be formatted using `{:?}` because it doesn't implement `Debug` - | - = note: required for `(U, u32)` to implement `Debug` -help: consider restricting type parameter `U` - | -LL | type Two = impl Debug; - | +++++++++++++++++ +error: aborting due to 1 previous error -error: aborting due to 2 previous errors - -For more information about this error, try `rustc --explain E0277`. diff --git a/tests/ui/type-alias-impl-trait/generic_duplicate_param_use9.rs b/tests/ui/type-alias-impl-trait/generic_duplicate_param_use9.rs index 6afcdfe4d1c..5da7aab0da7 100644 --- a/tests/ui/type-alias-impl-trait/generic_duplicate_param_use9.rs +++ b/tests/ui/type-alias-impl-trait/generic_duplicate_param_use9.rs @@ -13,13 +13,9 @@ trait Foo { fn two(t: T, u: U) -> Two { (t, u, T::BAR) - //~^ ERROR the trait bound `A: Foo` is not satisfied - //~| ERROR `A` doesn't implement `Debug` - //~| ERROR `B` doesn't implement `Debug` } fn three(t: T, u: U) -> Two { (t, u, 42) - //~^ ERROR `A` doesn't implement `Debug` - //~| ERROR `B` doesn't implement `Debug` + //~^ ERROR concrete type differs } diff --git a/tests/ui/type-alias-impl-trait/generic_duplicate_param_use9.stderr b/tests/ui/type-alias-impl-trait/generic_duplicate_param_use9.stderr index 722693e4266..6e1bb3dfa17 100644 --- a/tests/ui/type-alias-impl-trait/generic_duplicate_param_use9.stderr +++ b/tests/ui/type-alias-impl-trait/generic_duplicate_param_use9.stderr @@ -1,62 +1,14 @@ -error[E0277]: the trait bound `A: Foo` is not satisfied - --> $DIR/generic_duplicate_param_use9.rs:15:5 - | -LL | (t, u, T::BAR) - | ^^^^^^^^^^^^^^ the trait `Foo` is not implemented for `A` - | -help: consider restricting type parameter `A` - | -LL | type Two = impl Debug; - | +++++ - -error[E0277]: `A` doesn't implement `Debug` - --> $DIR/generic_duplicate_param_use9.rs:15:5 - | -LL | (t, u, T::BAR) - | ^^^^^^^^^^^^^^ `A` cannot be formatted using `{:?}` because it doesn't implement `Debug` - | - = note: required for `(A, B, _)` to implement `Debug` -help: consider restricting type parameter `A` - | -LL | type Two = impl Debug; - | +++++++++++++++++ - -error[E0277]: `B` doesn't implement `Debug` - --> $DIR/generic_duplicate_param_use9.rs:15:5 - | -LL | (t, u, T::BAR) - | ^^^^^^^^^^^^^^ `B` cannot be formatted using `{:?}` because it doesn't implement `Debug` - | - = note: required for `(A, B, _)` to implement `Debug` -help: consider restricting type parameter `B` - | -LL | type Two = impl Debug; - | +++++++++++++++++ - -error[E0277]: `A` doesn't implement `Debug` - --> $DIR/generic_duplicate_param_use9.rs:22:5 +error: concrete type differs from previous defining opaque type use + --> $DIR/generic_duplicate_param_use9.rs:19:5 | LL | (t, u, 42) - | ^^^^^^^^^^ `A` cannot be formatted using `{:?}` because it doesn't implement `Debug` + | ^^^^^^^^^^ expected `(A, B, ::Bar)`, got `(A, B, i32)` | - = note: required for `(A, B, i32)` to implement `Debug` -help: consider restricting type parameter `A` +note: previous use here + --> $DIR/generic_duplicate_param_use9.rs:15:5 | -LL | type Two = impl Debug; - | +++++++++++++++++ +LL | (t, u, T::BAR) + | ^^^^^^^^^^^^^^ -error[E0277]: `B` doesn't implement `Debug` - --> $DIR/generic_duplicate_param_use9.rs:22:5 - | -LL | (t, u, 42) - | ^^^^^^^^^^ `B` cannot be formatted using `{:?}` because it doesn't implement `Debug` - | - = note: required for `(A, B, i32)` to implement `Debug` -help: consider restricting type parameter `B` - | -LL | type Two = impl Debug; - | +++++++++++++++++ +error: aborting due to 1 previous error -error: aborting due to 5 previous errors - -For more information about this error, try `rustc --explain E0277`. diff --git a/tests/ui/type-alias-impl-trait/implied_lifetime_wf_check4_static.rs b/tests/ui/type-alias-impl-trait/implied_lifetime_wf_check4_static.rs index f8b09814caa..7b2bbc99530 100644 --- a/tests/ui/type-alias-impl-trait/implied_lifetime_wf_check4_static.rs +++ b/tests/ui/type-alias-impl-trait/implied_lifetime_wf_check4_static.rs @@ -2,9 +2,9 @@ mod test_type_param_static { pub type Ty = impl Sized + 'static; - //~^ ERROR: the parameter type `A` may not live long enough fn defining(s: A) -> Ty { s + //~^ ERROR: the parameter type `A` may not live long enough } pub fn assert_static() {} } diff --git a/tests/ui/type-alias-impl-trait/implied_lifetime_wf_check4_static.stderr b/tests/ui/type-alias-impl-trait/implied_lifetime_wf_check4_static.stderr index f2e5e95b96f..e5919be0532 100644 --- a/tests/ui/type-alias-impl-trait/implied_lifetime_wf_check4_static.stderr +++ b/tests/ui/type-alias-impl-trait/implied_lifetime_wf_check4_static.stderr @@ -1,11 +1,11 @@ error[E0310]: the parameter type `A` may not live long enough - --> $DIR/implied_lifetime_wf_check4_static.rs:4:22 + --> $DIR/implied_lifetime_wf_check4_static.rs:6:9 | -LL | pub type Ty = impl Sized + 'static; - | ^^^^^^^^^^^^^^^^^^^^ - | | - | the parameter type `A` must be valid for the static lifetime... - | ...so that the type `A` will meet its required lifetime bounds +LL | s + | ^ + | | + | the parameter type `A` must be valid for the static lifetime... + | ...so that the type `A` will meet its required lifetime bounds | help: consider adding an explicit lifetime bound | diff --git a/tests/ui/type-alias-impl-trait/not_a_defining_use.rs b/tests/ui/type-alias-impl-trait/not_a_defining_use.rs index fa47d13f516..b5ef1470629 100644 --- a/tests/ui/type-alias-impl-trait/not_a_defining_use.rs +++ b/tests/ui/type-alias-impl-trait/not_a_defining_use.rs @@ -8,7 +8,6 @@ fn main() {} fn three(t: T) -> Two { (t, 5i8) - //~^ ERROR `T` doesn't implement `Debug` } trait Bar { @@ -23,8 +22,7 @@ impl Bar for u32 { fn four(t: T) -> Two { (t, ::FOO) - //~^ ERROR `U: Bar` is not satisfied - //~| ERROR `T` doesn't implement `Debug` + //~^ ERROR concrete type differs } fn is_sync() {} diff --git a/tests/ui/type-alias-impl-trait/not_a_defining_use.stderr b/tests/ui/type-alias-impl-trait/not_a_defining_use.stderr index b11198c584c..b59f9c49b07 100644 --- a/tests/ui/type-alias-impl-trait/not_a_defining_use.stderr +++ b/tests/ui/type-alias-impl-trait/not_a_defining_use.stderr @@ -1,38 +1,14 @@ -error[E0277]: `T` doesn't implement `Debug` +error: concrete type differs from previous defining opaque type use + --> $DIR/not_a_defining_use.rs:24:5 + | +LL | (t, ::FOO) + | ^^^^^^^^^^^^^^^^^^^^ expected `(T, i8)`, got `(T, ::Blub)` + | +note: previous use here --> $DIR/not_a_defining_use.rs:10:5 | LL | (t, 5i8) - | ^^^^^^^^ `T` cannot be formatted using `{:?}` because it doesn't implement `Debug` - | - = note: required for `(T, i8)` to implement `Debug` -help: consider restricting type parameter `T` - | -LL | type Two = impl Debug; - | +++++++++++++++++ + | ^^^^^^^^ -error[E0277]: the trait bound `U: Bar` is not satisfied - --> $DIR/not_a_defining_use.rs:25:5 - | -LL | (t, ::FOO) - | ^^^^^^^^^^^^^^^^^^^^ the trait `Bar` is not implemented for `U` - | -help: consider restricting type parameter `U` - | -LL | type Two = impl Debug; - | +++++ +error: aborting due to 1 previous error -error[E0277]: `T` doesn't implement `Debug` - --> $DIR/not_a_defining_use.rs:25:5 - | -LL | (t, ::FOO) - | ^^^^^^^^^^^^^^^^^^^^ `T` cannot be formatted using `{:?}` because it doesn't implement `Debug` - | - = note: required for `(T, _)` to implement `Debug` -help: consider restricting type parameter `T` - | -LL | type Two = impl Debug; - | +++++++++++++++++ - -error: aborting due to 3 previous errors - -For more information about this error, try `rustc --explain E0277`. diff --git a/tests/ui/type-alias-impl-trait/underconstrained_lifetime.rs b/tests/ui/type-alias-impl-trait/underconstrained_lifetime.rs index c5b2e8a1c5e..e8e7dd0ea08 100644 --- a/tests/ui/type-alias-impl-trait/underconstrained_lifetime.rs +++ b/tests/ui/type-alias-impl-trait/underconstrained_lifetime.rs @@ -13,11 +13,11 @@ fn convert(_: PhantomData, r: &'a T) -> &'b T { } type Converter<'a, 'b> = impl ProofForConversion<'a, 'b>; -//~^ ERROR reference has a longer lifetime than the data it references // Even _defining_use with an explicit `'a: 'b` compiles fine, too. fn _defining_use<'a, 'b>(x: &'b &'a ()) -> Converter<'a, 'b> { x + //~^ ERROR reference has a longer lifetime than the data it references } fn extend_lifetime<'a, 'b, T: ?Sized>(x: &'a T) -> &'b T { diff --git a/tests/ui/type-alias-impl-trait/underconstrained_lifetime.stderr b/tests/ui/type-alias-impl-trait/underconstrained_lifetime.stderr index 34b50fb1f05..7c07578d887 100644 --- a/tests/ui/type-alias-impl-trait/underconstrained_lifetime.stderr +++ b/tests/ui/type-alias-impl-trait/underconstrained_lifetime.stderr @@ -1,8 +1,8 @@ error[E0491]: in type `&'b &'a ()`, reference has a longer lifetime than the data it references - --> $DIR/underconstrained_lifetime.rs:15:26 + --> $DIR/underconstrained_lifetime.rs:19:5 | -LL | type Converter<'a, 'b> = impl ProofForConversion<'a, 'b>; - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +LL | x + | ^ | note: the pointer is valid for the lifetime `'b` as defined here --> $DIR/underconstrained_lifetime.rs:15:20 diff --git a/tests/ui/type-alias-impl-trait/wf-in-associated-type.fail.stderr b/tests/ui/type-alias-impl-trait/wf-in-associated-type.fail.stderr index c4ad8434ed1..03ff2e3444b 100644 --- a/tests/ui/type-alias-impl-trait/wf-in-associated-type.fail.stderr +++ b/tests/ui/type-alias-impl-trait/wf-in-associated-type.fail.stderr @@ -1,10 +1,11 @@ error[E0309]: the parameter type `T` may not live long enough - --> $DIR/wf-in-associated-type.rs:38:23 + --> $DIR/wf-in-associated-type.rs:40:13 | LL | impl<'a, T> Trait<'a, T> for () { | -- the parameter type `T` must be valid for the lifetime `'a` as defined here... -LL | type Opaque = impl Sized + 'a; - | ^^^^^^^^^^^^^^^ ...so that the type `&'a T` will meet its required lifetime bounds +... +LL | req + | ^^^ ...so that the type `&'a T` will meet its required lifetime bounds | help: consider adding an explicit lifetime bound | @@ -12,12 +13,13 @@ LL | impl<'a, T: 'a> Trait<'a, T> for () { | ++++ error[E0309]: the parameter type `T` may not live long enough - --> $DIR/wf-in-associated-type.rs:38:23 + --> $DIR/wf-in-associated-type.rs:40:13 | LL | impl<'a, T> Trait<'a, T> for () { | -- the parameter type `T` must be valid for the lifetime `'a` as defined here... -LL | type Opaque = impl Sized + 'a; - | ^^^^^^^^^^^^^^^ ...so that the reference type `&'a T` does not outlive the data it points at +... +LL | req + | ^^^ ...so that the reference type `&'a T` does not outlive the data it points at | help: consider adding an explicit lifetime bound | diff --git a/tests/ui/type-alias-impl-trait/wf-in-associated-type.rs b/tests/ui/type-alias-impl-trait/wf-in-associated-type.rs index c20be3125bc..e548609e89a 100644 --- a/tests/ui/type-alias-impl-trait/wf-in-associated-type.rs +++ b/tests/ui/type-alias-impl-trait/wf-in-associated-type.rs @@ -36,10 +36,10 @@ trait Trait<'a, T> { impl<'a, T> Trait<'a, T> for () { type Opaque = impl Sized + 'a; - //[fail]~^ ERROR the parameter type `T` may not live long enough - //[fail]~| ERROR the parameter type `T` may not live long enough fn constrain_opaque(req: &'a T) -> Self::Opaque { req + //[fail]~^ ERROR the parameter type `T` may not live long enough + //[fail]~| ERROR the parameter type `T` may not live long enough } } }