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Revert "Auto merge of #92306 - Aaron1011:opaque-type-op, r=oli-obk"

Browse Source 
This reverts commit 1f0a96862a, reversing
changes made to bf242bb119.
This commit is contained in:
Oli Scherer 2022-02-11 07:17:16 +00:00
parent 7a71b7a99e
commit 2d8b8f3593
14 changed files with 71 additions and 231 deletions
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108
compiler/rustc_borrowck/src/diagnostics/bound_region_errors.rs
View File

@ -2,13 +2,9 @@ use rustc_errors::DiagnosticBuilder;
use rustc_infer::infer::canonical::Canonical;
use rustc_infer::infer::error_reporting::nice_region_error::NiceRegionError;
use rustc_infer::infer::region_constraints::Constraint;
use rustc_infer::infer::region_constraints::RegionConstraintData;
use rustc_infer::infer::RegionVariableOrigin;
use rustc_infer::infer::{InferCtxt, RegionResolutionError, SubregionOrigin, TyCtxtInferExt as _};
use rustc_infer::traits::{Normalized, ObligationCause, TraitEngine, TraitEngineExt};
use rustc_middle::ty::error::TypeError;
use rustc_middle::ty::RegionVid;
use rustc_middle::ty::UniverseIndex;
use rustc_middle::ty::{self, Ty, TyCtxt, TypeFoldable};
use rustc_span::Span;
use rustc_trait_selection::traits::query::type_op;
@ -82,15 +78,6 @@ crate trait ToUniverseInfo<'tcx> {
fn to_universe_info(self, base_universe: ty::UniverseIndex) -> UniverseInfo<'tcx>;
}
impl<'tcx> ToUniverseInfo<'tcx> for crate::type_check::InstantiateOpaqueType<'tcx> {
fn to_universe_info(self, base_universe: ty::UniverseIndex) -> UniverseInfo<'tcx> {
UniverseInfo(UniverseInfoInner::TypeOp(Rc::new(crate::type_check::InstantiateOpaqueType {
base_universe: Some(base_universe),
..self
})))
}
}
impl<'tcx> ToUniverseInfo<'tcx>
for Canonical<'tcx, ty::ParamEnvAnd<'tcx, type_op::prove_predicate::ProvePredicate<'tcx>>>
{
@ -131,12 +118,6 @@ impl<'tcx, F, G> ToUniverseInfo<'tcx> for Canonical<'tcx, type_op::custom::Custo
}
}
impl<'tcx> ToUniverseInfo<'tcx> for ! {
fn to_universe_info(self, _base_universe: ty::UniverseIndex) -> UniverseInfo<'tcx> {
self
}
}
#[allow(unused_lifetimes)]
trait TypeOpInfo<'tcx> {
/// Returns an error to be reported if rerunning the type op fails to
@ -147,7 +128,7 @@ trait TypeOpInfo<'tcx> {
fn nice_error(
&self,
mbcx: &mut MirBorrowckCtxt<'_, 'tcx>,
tcx: TyCtxt<'tcx>,
cause: ObligationCause<'tcx>,
placeholder_region: ty::Region<'tcx>,
error_region: Option<ty::Region<'tcx>>,
@ -194,7 +175,7 @@ trait TypeOpInfo<'tcx> {
debug!(?placeholder_region);
let span = cause.span;
let nice_error = self.nice_error(mbcx, cause, placeholder_region, error_region);
let nice_error = self.nice_error(tcx, cause, placeholder_region, error_region);
if let Some(nice_error) = nice_error {
nice_error.buffer(&mut mbcx.errors_buffer);
@ -223,16 +204,16 @@ impl<'tcx> TypeOpInfo<'tcx> for PredicateQuery<'tcx> {
fn nice_error(
&self,
mbcx: &mut MirBorrowckCtxt<'_, 'tcx>,
tcx: TyCtxt<'tcx>,
cause: ObligationCause<'tcx>,
placeholder_region: ty::Region<'tcx>,
error_region: Option<ty::Region<'tcx>>,
) -> Option<DiagnosticBuilder<'tcx>> {
mbcx.infcx.tcx.infer_ctxt().enter_with_canonical(
tcx.infer_ctxt().enter_with_canonical(
cause.span,
&self.canonical_query,
|ref infcx, key, _| {
let mut fulfill_cx = <dyn TraitEngine<'_>>::new(infcx.tcx);
let mut fulfill_cx = <dyn TraitEngine<'_>>::new(tcx);
type_op_prove_predicate_with_cause(infcx, &mut *fulfill_cx, key, cause);
try_extract_error_from_fulfill_cx(
fulfill_cx,
@ -266,16 +247,16 @@ where
fn nice_error(
&self,
mbcx: &mut MirBorrowckCtxt<'_, 'tcx>,
tcx: TyCtxt<'tcx>,
cause: ObligationCause<'tcx>,
placeholder_region: ty::Region<'tcx>,
error_region: Option<ty::Region<'tcx>>,
) -> Option<DiagnosticBuilder<'tcx>> {
mbcx.infcx.tcx.infer_ctxt().enter_with_canonical(
tcx.infer_ctxt().enter_with_canonical(
cause.span,
&self.canonical_query,
|ref infcx, key, _| {
let mut fulfill_cx = <dyn TraitEngine<'_>>::new(infcx.tcx);
let mut fulfill_cx = <dyn TraitEngine<'_>>::new(tcx);
let mut selcx = SelectionContext::new(infcx);
@ -323,16 +304,16 @@ impl<'tcx> TypeOpInfo<'tcx> for AscribeUserTypeQuery<'tcx> {
fn nice_error(
&self,
mbcx: &mut MirBorrowckCtxt<'_, 'tcx>,
tcx: TyCtxt<'tcx>,
cause: ObligationCause<'tcx>,
placeholder_region: ty::Region<'tcx>,
error_region: Option<ty::Region<'tcx>>,
) -> Option<DiagnosticBuilder<'tcx>> {
mbcx.infcx.tcx.infer_ctxt().enter_with_canonical(
tcx.infer_ctxt().enter_with_canonical(
cause.span,
&self.canonical_query,
|ref infcx, key, _| {
let mut fulfill_cx = <dyn TraitEngine<'_>>::new(infcx.tcx);
let mut fulfill_cx = <dyn TraitEngine<'_>>::new(tcx);
type_op_ascribe_user_type_with_span(infcx, &mut *fulfill_cx, key, Some(cause.span))
.ok()?;
try_extract_error_from_fulfill_cx(
@ -346,39 +327,6 @@ impl<'tcx> TypeOpInfo<'tcx> for AscribeUserTypeQuery<'tcx> {
}
}
impl<'tcx> TypeOpInfo<'tcx> for crate::type_check::InstantiateOpaqueType<'tcx> {
fn fallback_error(&self, tcx: TyCtxt<'tcx>, span: Span) -> DiagnosticBuilder<'tcx> {
// FIXME: This error message isn't great, but it doesn't show up in the existing UI tests,
// and is only the fallback when the nice error fails. Consider improving this some more.
tcx.sess.struct_span_err(span, "higher-ranked lifetime error for opaque type!")
}
fn base_universe(&self) -> ty::UniverseIndex {
self.base_universe.unwrap()
}
fn nice_error(
&self,
mbcx: &mut MirBorrowckCtxt<'_, 'tcx>,
_cause: ObligationCause<'tcx>,
placeholder_region: ty::Region<'tcx>,
error_region: Option<ty::Region<'tcx>>,
) -> Option<DiagnosticBuilder<'tcx>> {
try_extract_error_from_region_constraints(
mbcx.infcx,
placeholder_region,
error_region,
self.region_constraints.as_ref().unwrap(),
// We're using the original `InferCtxt` that we
// started MIR borrowchecking with, so the region
// constraints have already been taken. Use the data from
// our `mbcx` instead.
|vid| mbcx.regioncx.var_infos[vid].origin,
|vid| mbcx.regioncx.var_infos[vid].universe,
)
}
}
#[instrument(skip(fulfill_cx, infcx), level = "debug")]
fn try_extract_error_from_fulfill_cx<'tcx>(
mut fulfill_cx: Box<dyn TraitEngine<'tcx> + 'tcx>,
@ -386,30 +334,15 @@ fn try_extract_error_from_fulfill_cx<'tcx>(
placeholder_region: ty::Region<'tcx>,
error_region: Option<ty::Region<'tcx>>,
) -> Option<DiagnosticBuilder<'tcx>> {
let tcx = infcx.tcx;
// We generally shouldn't have errors here because the query was
// already run, but there's no point using `delay_span_bug`
// when we're going to emit an error here anyway.
let _errors = fulfill_cx.select_all_or_error(infcx);
let region_constraints = infcx.with_region_constraints(|r| r.clone());
try_extract_error_from_region_constraints(
infcx,
placeholder_region,
error_region,
&region_constraints,
|vid| infcx.region_var_origin(vid),
|vid| infcx.universe_of_region(infcx.tcx.mk_region(ty::ReVar(vid))),
)
}
fn try_extract_error_from_region_constraints<'tcx>(
infcx: &InferCtxt<'_, 'tcx>,
placeholder_region: ty::Region<'tcx>,
error_region: Option<ty::Region<'tcx>>,
region_constraints: &RegionConstraintData<'tcx>,
mut region_var_origin: impl FnMut(RegionVid) -> RegionVariableOrigin,
mut universe_of_region: impl FnMut(RegionVid) -> UniverseIndex,
) -> Option<DiagnosticBuilder<'tcx>> {
let (sub_region, cause) =
let (sub_region, cause) = infcx.with_region_constraints(|region_constraints| {
debug!("{:#?}", region_constraints);
region_constraints.constraints.iter().find_map(|(constraint, cause)| {
match *constraint {
Constraint::RegSubReg(sub, sup) if sup == placeholder_region && sup != sub => {
@ -417,11 +350,12 @@ fn try_extract_error_from_region_constraints<'tcx>(
}
// FIXME: Should this check the universe of the var?
Constraint::VarSubReg(vid, sup) if sup == placeholder_region => {
Some((infcx.tcx.mk_region(ty::ReVar(vid)), cause.clone()))
Some((tcx.mk_region(ty::ReVar(vid)), cause.clone()))
}
_ => None,
}
})?;
})
})?;
debug!(?sub_region, "cause = {:#?}", cause);
let nice_error = match (error_region, sub_region) {
@ -429,7 +363,7 @@ fn try_extract_error_from_region_constraints<'tcx>(
infcx,
RegionResolutionError::SubSupConflict(
vid,
region_var_origin(vid),
infcx.region_var_origin(vid),
cause.clone(),
error_region,
cause.clone(),
@ -446,8 +380,8 @@ fn try_extract_error_from_region_constraints<'tcx>(
infcx,
RegionResolutionError::UpperBoundUniverseConflict(
vid,
region_var_origin(vid),
universe_of_region(vid),
infcx.region_var_origin(vid),
infcx.universe_of_region(sub_region),
cause.clone(),
placeholder_region,
),

1
compiler/rustc_borrowck/src/lib.rs
View File

@ -5,7 +5,6 @@
#![feature(crate_visibility_modifier)]
#![feature(let_else)]
#![feature(min_specialization)]
#![feature(never_type)]
#![feature(stmt_expr_attributes)]
#![feature(trusted_step)]
#![feature(try_blocks)]

4
compiler/rustc_borrowck/src/region_infer/mod.rs
View File

@ -44,7 +44,6 @@ mod reverse_sccs;
pub mod values;
pub struct RegionInferenceContext<'tcx> {
pub var_infos: VarInfos,
/// Contains the definition for every region variable. Region
/// variables are identified by their index (`RegionVid`). The
/// definition contains information about where the region came
@ -267,7 +266,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
) -> Self {
// Create a RegionDefinition for each inference variable.
let definitions: IndexVec<_, _> = var_infos
.iter()
.into_iter()
.map(|info| RegionDefinition::new(info.universe, info.origin))
.collect();
@ -292,7 +291,6 @@ impl<'tcx> RegionInferenceContext<'tcx> {
Rc::new(member_constraints_in.into_mapped(|r| constraint_sccs.scc(r)));
let mut result = Self {
var_infos,
definitions,
liveness_constraints,
constraints,

9
compiler/rustc_borrowck/src/type_check/canonical.rs
View File

@ -33,11 +33,12 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
) -> Fallible<R>
where
Op: type_op::TypeOp<'tcx, Output = R>,
Op::ErrorInfo: ToUniverseInfo<'tcx>,
Canonical<'tcx, Op>: ToUniverseInfo<'tcx>,
{
let old_universe = self.infcx.universe();
let TypeOpOutput { output, constraints, error_info } = op.fully_perform(self.infcx)?;
let TypeOpOutput { output, constraints, canonicalized_query } =
op.fully_perform(self.infcx)?;
if let Some(data) = &constraints {
self.push_region_constraints(locations, category, data);
@ -46,8 +47,8 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
let universe = self.infcx.universe();
if old_universe != universe {
let universe_info = match error_info {
Some(error_info) => error_info.to_universe_info(old_universe),
let universe_info = match canonicalized_query {
Some(canonicalized_query) => canonicalized_query.to_universe_info(old_universe),
None => UniverseInfo::other(),
};
for u in old_universe..universe {

2
compiler/rustc_borrowck/src/type_check/free_region_relations.rs
View File

@ -268,7 +268,7 @@ impl<'tcx> UniversalRegionRelationsBuilder<'_, 'tcx> {
TypeOpOutput {
output: self.infcx.tcx.ty_error(),
constraints: None,
error_info: None,
canonicalized_query: None,
}
});
// Note: we need this in examples like

34
compiler/rustc_borrowck/src/type_check/mod.rs
View File

@ -17,7 +17,6 @@ use rustc_hir::lang_items::LangItem;
use rustc_index::vec::{Idx, IndexVec};
use rustc_infer::infer::canonical::QueryRegionConstraints;
use rustc_infer::infer::outlives::env::RegionBoundPairs;
use rustc_infer::infer::region_constraints::RegionConstraintData;
use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
use rustc_infer::infer::{
InferCtxt, InferOk, LateBoundRegionConversionTime, NllRegionVariableOrigin,
@ -40,11 +39,9 @@ use rustc_target::abi::VariantIdx;
use rustc_trait_selection::infer::InferCtxtExt as _;
use rustc_trait_selection::traits::error_reporting::InferCtxtExt as _;
use rustc_trait_selection::traits::query::type_op;
use rustc_trait_selection::traits::query::type_op::custom::scrape_region_constraints;
use rustc_trait_selection::traits::query::type_op::custom::CustomTypeOp;
use rustc_trait_selection::traits::query::type_op::{TypeOp, TypeOpOutput};
use rustc_trait_selection::traits::query::Fallible;
use rustc_trait_selection::traits::{self, ObligationCause, PredicateObligation};
use rustc_trait_selection::traits::{self, ObligationCause};
use rustc_const_eval::transform::{
check_consts::ConstCx, promote_consts::is_const_fn_in_array_repeat_expression,
@ -2640,32 +2637,3 @@ impl NormalizeLocation for Location {
Locations::Single(self)
}
}
/// Runs `infcx.instantiate_opaque_types`. Unlike other `TypeOp`s,
/// this is not canonicalized - it directly affects the main `InferCtxt`
/// that we use during MIR borrowchecking.
#[derive(Debug)]
pub(super) struct InstantiateOpaqueType<'tcx> {
pub base_universe: Option<ty::UniverseIndex>,
pub region_constraints: Option<RegionConstraintData<'tcx>>,
pub obligation: PredicateObligation<'tcx>,
}
impl<'tcx> TypeOp<'tcx> for InstantiateOpaqueType<'tcx> {
type Output = ();
/// We use this type itself to store the information used
/// when reporting errors. Since this is not a query, we don't
/// re-run anything during error reporting - we just use the information
/// we saved to help extract an error from the already-existing region
/// constraints in our `InferCtxt`
type ErrorInfo = InstantiateOpaqueType<'tcx>;
fn fully_perform(mut self, infcx: &InferCtxt<'_, 'tcx>) -> Fallible<TypeOpOutput<'tcx, Self>> {
let (mut output, region_constraints) = scrape_region_constraints(infcx, || {
Ok(InferOk { value: (), obligations: vec![self.obligation.clone()] })
})?;
self.region_constraints = Some(region_constraints);
output.error_info = Some(self);
Ok(output)
}
}

31
compiler/rustc_borrowck/src/type_check/relate_tys.rs
View File

@ -1,5 +1,5 @@
use rustc_infer::infer::nll_relate::{NormalizationStrategy, TypeRelating, TypeRelatingDelegate};
use rustc_infer::infer::NllRegionVariableOrigin;
use rustc_infer::infer::{InferOk, NllRegionVariableOrigin};
use rustc_infer::traits::ObligationCause;
use rustc_middle::mir::ConstraintCategory;
use rustc_middle::ty::relate::TypeRelation;
@ -9,7 +9,7 @@ use rustc_trait_selection::traits::query::Fallible;
use crate::constraints::OutlivesConstraint;
use crate::diagnostics::UniverseInfo;
use crate::type_check::{InstantiateOpaqueType, Locations, TypeChecker};
use crate::type_check::{CustomTypeOp, Locations, TypeChecker};
impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
/// Adds sufficient constraints to ensure that `a R b` where `R` depends on `v`:
@ -146,18 +146,21 @@ impl<'tcx> TypeRelatingDelegate<'tcx> for NllTypeRelatingDelegate<'_, '_, 'tcx>
.fully_perform_op(
self.locations,
self.category,
InstantiateOpaqueType {
obligation: self.type_checker.infcx.opaque_ty_obligation(
a,
b,
a_is_expected,
param_env,
cause,
),
// These fields are filled in during exectuion of the operation
base_universe: None,
region_constraints: None,
},
CustomTypeOp::new(
|infcx| {
Ok(InferOk {
value: (),
obligations: vec![infcx.opaque_ty_obligation(
a,
b,
a_is_expected,
param_env,
cause,
)],
})
},
|| "register_opaque_type".to_string(),
),
)
.unwrap();
}

1
compiler/rustc_infer/src/lib.rs
View File

@ -22,7 +22,6 @@
#![feature(control_flow_enum)]
#![feature(min_specialization)]
#![feature(label_break_value)]
#![feature(backtrace)]
#![recursion_limit = "512"] // For rustdoc
#![cfg_attr(not(bootstrap), allow(rustc::potential_query_instability))]

28
compiler/rustc_trait_selection/src/traits/query/type_op/custom.rs
View File

@ -4,7 +4,6 @@ use crate::traits::engine::TraitEngineExt as _;
use crate::traits::query::type_op::TypeOpOutput;
use crate::traits::query::Fallible;
use crate::traits::TraitEngine;
use rustc_infer::infer::region_constraints::RegionConstraintData;
use rustc_infer::traits::TraitEngineExt as _;
use rustc_span::source_map::DUMMY_SP;
@ -32,9 +31,6 @@ where
G: Fn() -> String,
{
type Output = R;
/// We can't do any custom error reporting for `CustomTypeOp`, so
/// we can use `!` to enforce that the implementation never provides it.
type ErrorInfo = !;
/// Processes the operation and all resulting obligations,
/// returning the final result along with any region constraints
@ -44,7 +40,7 @@ where
info!("fully_perform({:?})", self);
}
Ok(scrape_region_constraints(infcx, || (self.closure)(infcx))?.0)
scrape_region_constraints(infcx, || (self.closure)(infcx))
}
}
@ -59,10 +55,10 @@ where
/// Executes `op` and then scrapes out all the "old style" region
/// constraints that result, creating query-region-constraints.
pub fn scrape_region_constraints<'tcx, Op: super::TypeOp<'tcx, Output = R>, R>(
fn scrape_region_constraints<'tcx, Op: super::TypeOp<'tcx, Output = R>, R>(
infcx: &InferCtxt<'_, 'tcx>,
op: impl FnOnce() -> Fallible<InferOk<'tcx, R>>,
) -> Fallible<(TypeOpOutput<'tcx, Op>, RegionConstraintData<'tcx>)> {
) -> Fallible<TypeOpOutput<'tcx, Op>> {
let mut fulfill_cx = <dyn TraitEngine<'_>>::new(infcx.tcx);
// During NLL, we expect that nobody will register region
@ -101,18 +97,12 @@ pub fn scrape_region_constraints<'tcx, Op: super::TypeOp<'tcx, Output = R>, R>(
);
if region_constraints.is_empty() {
Ok((
TypeOpOutput { output: value, constraints: None, error_info: None },
region_constraint_data,
))
Ok(TypeOpOutput { output: value, constraints: None, canonicalized_query: None })
} else {
Ok((
TypeOpOutput {
output: value,
constraints: Some(Rc::new(region_constraints)),
error_info: None,
},
region_constraint_data,
))
Ok(TypeOpOutput {
output: value,
constraints: Some(Rc::new(region_constraints)),
canonicalized_query: None,
})
}
}

11
compiler/rustc_trait_selection/src/traits/query/type_op/mod.rs
View File

@ -28,7 +28,6 @@ pub use rustc_middle::traits::query::type_op::*;
/// cannot be completed).
pub trait TypeOp<'tcx>: Sized + fmt::Debug {
type Output;
type ErrorInfo;
/// Processes the operation and all resulting obligations,
/// returning the final result along with any region constraints
@ -42,8 +41,9 @@ pub struct TypeOpOutput<'tcx, Op: TypeOp<'tcx>> {
pub output: Op::Output,
/// Any region constraints from performing the type op.
pub constraints: Option<Rc<QueryRegionConstraints<'tcx>>>,
/// Used for error reporting to be able to rerun the query
pub error_info: Option<Op::ErrorInfo>,
/// The canonicalized form of the query.
/// This for error reporting to be able to rerun the query.
pub canonicalized_query: Option<Canonical<'tcx, Op>>,
}
/// "Query type ops" are type ops that are implemented using a
@ -119,11 +119,10 @@ where
Q: QueryTypeOp<'tcx>,
{
type Output = Q::QueryResponse;
type ErrorInfo = Canonical<'tcx, ParamEnvAnd<'tcx, Q>>;
fn fully_perform(self, infcx: &InferCtxt<'_, 'tcx>) -> Fallible<TypeOpOutput<'tcx, Self>> {
let mut region_constraints = QueryRegionConstraints::default();
let (output, error_info, mut obligations, _) =
let (output, canonicalized_query, mut obligations, _) =
Q::fully_perform_into(self, infcx, &mut region_constraints)?;
// Typically, instantiating NLL query results does not
@ -161,6 +160,6 @@ where
let region_constraints =
if region_constraints.is_empty() { None } else { Some(Rc::new(region_constraints)) };
Ok(TypeOpOutput { output, constraints: region_constraints, error_info })
Ok(TypeOpOutput { output, constraints: region_constraints, canonicalized_query })
}
}

28
src/test/ui/impl-trait/issues/issue-88236-2.nll.stderr
View File

@ -1,20 +1,14 @@
error: implementation of `Hrtb` is not general enough
error: higher-ranked subtype error
--> $DIR/issue-88236-2.rs:17:5
|
LL | &()
| ^^^ implementation of `Hrtb` is not general enough
|
= note: `Hrtb<'0>` would have to be implemented for the type `&()`, for any lifetime `'0`...
= note: ...but `Hrtb<'1>` is actually implemented for the type `&'1 ()`, for some specific lifetime `'1`
| ^^^
error: implementation of `Hrtb` is not general enough
error: higher-ranked subtype error
--> $DIR/issue-88236-2.rs:17:5
|
LL | &()
| ^^^ implementation of `Hrtb` is not general enough
|
= note: `Hrtb<'0>` would have to be implemented for the type `&()`, for any lifetime `'0`...
= note: ...but `Hrtb<'1>` is actually implemented for the type `&'1 ()`, for some specific lifetime `'1`
| ^^^
error: lifetime may not live long enough
--> $DIR/issue-88236-2.rs:20:5
@ -29,23 +23,17 @@ help: to allow this `impl Trait` to capture borrowed data with lifetime `'b`, ad
LL | fn make_bad_impl<'b>(x: &'b ()) -> impl for<'a> Hrtb<'a, Assoc = impl Send + 'a> + 'b {
| ++++
error: implementation of `Hrtb` is not general enough
error: higher-ranked subtype error
--> $DIR/issue-88236-2.rs:20:5
|
LL | x
| ^ implementation of `Hrtb` is not general enough
|
= note: `Hrtb<'0>` would have to be implemented for the type `&()`, for any lifetime `'0`...
= note: ...but `Hrtb<'1>` is actually implemented for the type `&'1 ()`, for some specific lifetime `'1`
| ^
error: implementation of `Hrtb` is not general enough
error: higher-ranked subtype error
--> $DIR/issue-88236-2.rs:20:5
|
LL | x
| ^ implementation of `Hrtb` is not general enough
|
= note: `Hrtb<'0>` would have to be implemented for the type `&()`, for any lifetime `'0`...
= note: ...but `Hrtb<'1>` is actually implemented for the type `&'1 ()`, for some specific lifetime `'1`
| ^
error: aborting due to 5 previous errors

16
src/test/ui/nll/relate_tys/opaque-hrtb.rs
View File

@ -1,16 +0,0 @@
#![feature(nll)]
trait MyTrait<T> {}
struct Foo;
impl<T> MyTrait<T> for Foo {}
fn bar<Input>() -> impl MyTrait<Input> {
Foo
}
fn foo() -> impl for<'a> MyTrait<&'a str> {
bar() //~ ERROR implementation of `MyTrait` is not general enough
}
fn main() {}

11
src/test/ui/nll/relate_tys/opaque-hrtb.stderr
View File

@ -1,11 +0,0 @@
error: implementation of `MyTrait` is not general enough
--> $DIR/opaque-hrtb.rs:13:5
|
LL | bar()
| ^^^^^ implementation of `MyTrait` is not general enough
|
= note: `impl MyTrait<&'2 str>` must implement `MyTrait<&'1 str>`, for any lifetime `'1`...
= note: ...but it actually implements `MyTrait<&'2 str>`, for some specific lifetime `'2`
error: aborting due to previous error

18
src/test/ui/type-alias-impl-trait/issue-57611-trait-alias.nll.stderr
View File

@ -1,26 +1,14 @@
error[E0308]: mismatched types
--> $DIR/issue-57611-trait-alias.rs:20:9
|
LL | |x| x
| ^^^^^ one type is more general than the other
|
= note: expected type `for<'r> Fn<(&'r X,)>`
found type `Fn<(&X,)>`
note: this closure does not fulfill the lifetime requirements
error: higher-ranked subtype error
--> $DIR/issue-57611-trait-alias.rs:20:9
|
LL | |x| x
| ^^^^^
error: implementation of `FnOnce` is not general enough
error: higher-ranked subtype error
--> $DIR/issue-57611-trait-alias.rs:20:9
|
LL | |x| x
| ^^^^^ implementation of `FnOnce` is not general enough
|
= note: closure with signature `fn(&'2 X) -> &X` must implement `FnOnce<(&'1 X,)>`, for any lifetime `'1`...
= note: ...but it actually implements `FnOnce<(&'2 X,)>`, for some specific lifetime `'2`
| ^^^^^
error: aborting due to 2 previous errors
For more information about this error, try `rustc --explain E0308`.