mirror of
https://github.com/rust-lang/rust
synced 2024-10-14 12:33:57 +00:00
Account for returned dyn Trait evaluating to 'static lifetime
Provide a suggestion for `dyn Trait + '_` when possible.
This commit is contained in:
Esteban Küber
parent
a724d9a4fb
commit
65f492be12
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@ -55,9 +55,9 @@ pub fn try_report(&self) -> Option<ErrorReported> {
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diag.emit();
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ErrorReported
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})
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.or_else(|| self.try_report_impl_not_conforming_to_trait())
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.or_else(|| self.try_report_anon_anon_conflict())
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.or_else(|| self.try_report_static_impl_trait())
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.or_else(|| self.try_report_impl_not_conforming_to_trait())
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}
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pub fn regions(&self) -> Option<(Span, ty::Region<'tcx>, ty::Region<'tcx>)> {
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@ -21,8 +21,8 @@ pub(super) fn try_report_named_anon_conflict(&self) -> Option<DiagnosticBuilder<
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// where the anonymous region appears (there must always be one; we
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// only introduced anonymous regions in parameters) as well as a
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// version new_ty of its type where the anonymous region is replaced
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// with the named one.//scope_def_id
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let (named, anon, anon_param_info, region_info) = if self.is_named_region(sub)
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// with the named one.
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let (named, anon, anon_param_info, region_info) = if sub.has_name()
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&& self.tcx().is_suitable_region(sup).is_some()
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&& self.find_param_with_region(sup, sub).is_some()
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{
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@ -32,7 +32,7 @@ pub(super) fn try_report_named_anon_conflict(&self) -> Option<DiagnosticBuilder<
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self.find_param_with_region(sup, sub).unwrap(),
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self.tcx().is_suitable_region(sup).unwrap(),
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)
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} else if self.is_named_region(sup)
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} else if sup.has_name()
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&& self.tcx().is_suitable_region(sub).is_some()
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&& self.find_param_with_region(sub, sup).is_some()
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{
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@ -74,24 +74,21 @@ pub(super) fn try_report_named_anon_conflict(&self) -> Option<DiagnosticBuilder<
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}
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if let Some((_, fndecl)) = self.find_anon_type(anon, &br) {
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let return_type_anon = self.is_return_type_anon(scope_def_id, br, fndecl);
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let is_self_anon = self.is_self_anon(is_first, scope_def_id);
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debug!(
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"try_report_named_anon_conflict: fndecl {:?} {:?} {}",
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fndecl, return_type_anon, is_self_anon
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);
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if is_self_anon {
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// We used to check for `return_type_anon.is_some()` here. Removing that improves
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// some diagnostics, but we might have to readd the check if there are regressions
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// in the wild.
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return None;
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}
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if let FnRetTy::Return(ty) = &fndecl.output {
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let mut v = ty::TraitObjectVisitor(vec![]);
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rustc_hir::intravisit::walk_ty(&mut v, ty);
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debug!("try_report_named_anon_conflict: ret ty {:?}", ty);
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if let (TyKind::Def(_, _), ty::ReStatic) = (&ty.kind, sub) {
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if sub == &ty::ReStatic && (matches!(ty.kind, TyKind::Def(_, _)) || v.0.len() == 1)
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{
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debug!("try_report_named_anon_conflict: impl Trait + 'static");
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// This is an impl Trait return that evaluates de need of 'static.
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// We handle this case better in `static_impl_trait`.
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// This is an `impl Trait` or `dyn Trait` return that evaluates de need of
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// `'static`. We handle this case better in `static_impl_trait`.
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return None;
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}
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}
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@ -123,17 +120,4 @@ pub(super) fn try_report_named_anon_conflict(&self) -> Option<DiagnosticBuilder<
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Some(diag)
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}
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// This method returns whether the given Region is Named
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pub(super) fn is_named_region(&self, region: ty::Region<'tcx>) -> bool {
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match *region {
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ty::ReStatic => true,
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ty::ReFree(ref free_region) => match free_region.bound_region {
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ty::BrNamed(..) => true,
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_ => false,
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},
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ty::ReEarlyBound(ebr) => ebr.has_name(),
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_ => false,
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}
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}
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}
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@ -20,16 +20,14 @@ pub(super) fn try_report_static_impl_trait(&self) -> Option<ErrorReported> {
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) = error.clone()
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{
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let anon_reg_sup = self.tcx().is_suitable_region(sup_r)?;
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let return_ty = self.tcx().return_type_impl_trait(anon_reg_sup.def_id);
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if sub_r == &RegionKind::ReStatic && return_ty.is_some() {
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let (fn_return_span, is_dyn) =
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self.tcx().return_type_impl_or_dyn_trait(anon_reg_sup.def_id)?;
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if sub_r == &RegionKind::ReStatic {
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let sp = var_origin.span();
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let return_sp = sub_origin.span();
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let mut err =
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self.tcx().sess.struct_span_err(sp, "cannot infer an appropriate lifetime");
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err.span_label(
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return_sp,
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"this return type evaluates to the `'static` lifetime...",
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);
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err.span_label(return_sp, "this evaluates to the `'static` lifetime...");
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err.span_label(sup_origin.span(), "...but this borrow...");
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let (lifetime, lt_sp_opt) = msg_span_from_free_region(self.tcx(), sup_r);
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@ -39,24 +37,22 @@ pub(super) fn try_report_static_impl_trait(&self) -> Option<ErrorReported> {
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let lifetime_name =
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if sup_r.has_name() { sup_r.to_string() } else { "'_".to_owned() };
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let fn_return_span = return_ty.unwrap().1;
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if let Ok(snippet) =
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self.tcx().sess.source_map().span_to_snippet(fn_return_span)
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{
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// only apply this suggestion onto functions with
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// explicit non-desugar'able return.
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if fn_return_span.desugaring_kind().is_none() {
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err.span_suggestion(
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fn_return_span,
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&format!(
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"you can add a bound to the return type to make it last less \
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than `'static` and match {}",
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lifetime
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),
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format!("{} + {}", snippet, lifetime_name),
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Applicability::Unspecified,
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);
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}
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// only apply this suggestion onto functions with
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// explicit non-desugar'able return.
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if fn_return_span.desugaring_kind().is_none() {
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let msg = format!(
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"you can add a bound to the returned `{} Trait` to make it last less \
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than `'static` and match {}",
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if is_dyn { "dyn" } else { "impl" },
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lifetime
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);
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// FIXME: account for the need of parens in `&(dyn Trait + '_)`
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err.span_suggestion_verbose(
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fn_return_span.shrink_to_hi(),
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&msg,
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format!(" + {}", lifetime_name),
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Applicability::MaybeIncorrect,
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);
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}
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err.emit();
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return Some(ErrorReported);
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@ -1,38 +1,27 @@
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//! Type context book-keeping.
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use crate::arena::Arena;
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use crate::dep_graph::DepGraph;
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use crate::dep_graph::{self, DepConstructor};
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use crate::dep_graph::{self, DepConstructor, DepGraph};
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use crate::hir::exports::Export;
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use crate::ich::{NodeIdHashingMode, StableHashingContext};
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use crate::infer::canonical::{Canonical, CanonicalVarInfo, CanonicalVarInfos};
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use crate::lint::LintDiagnosticBuilder;
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use crate::lint::{struct_lint_level, LintSource};
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use crate::lint::{struct_lint_level, LintDiagnosticBuilder, LintSource};
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use crate::middle;
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use crate::middle::cstore::CrateStoreDyn;
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use crate::middle::cstore::EncodedMetadata;
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use crate::middle::cstore::{CrateStoreDyn, EncodedMetadata};
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use crate::middle::resolve_lifetime::{self, ObjectLifetimeDefault};
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use crate::middle::stability;
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use crate::mir::interpret::{Allocation, ConstValue, Scalar};
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use crate::mir::{interpret, Body, Field, Local, Place, PlaceElem, ProjectionKind, Promoted};
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use crate::mir::interpret::{self, Allocation, ConstValue, Scalar};
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use crate::mir::{Body, Field, Local, Place, PlaceElem, ProjectionKind, Promoted};
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use crate::traits;
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use crate::ty::query;
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use crate::ty::steal::Steal;
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use crate::ty::subst::{GenericArg, InternalSubsts, Subst, SubstsRef};
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use crate::ty::subst::{GenericArgKind, UserSubsts};
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use crate::ty::CanonicalPolyFnSig;
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use crate::ty::GenericParamDefKind;
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use crate::ty::RegionKind;
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use crate::ty::ReprOptions;
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use crate::ty::subst::{GenericArg, GenericArgKind, InternalSubsts, Subst, SubstsRef, UserSubsts};
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use crate::ty::TyKind::*;
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use crate::ty::{self, DefIdTree, Ty, TypeAndMut};
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use crate::ty::{AdtDef, AdtKind, Const, Region};
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use crate::ty::{BindingMode, BoundVar};
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use crate::ty::{ConstVid, FloatVar, FloatVid, IntVar, IntVid, TyVar, TyVid};
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use crate::ty::{ExistentialPredicate, Predicate, PredicateKind};
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use crate::ty::{InferConst, ParamConst};
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use crate::ty::{InferTy, ParamTy, PolyFnSig, ProjectionTy};
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use crate::ty::{List, TyKind, TyS};
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use crate::ty::{
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self, query, AdtDef, AdtKind, BindingMode, BoundVar, CanonicalPolyFnSig, Const, ConstVid,
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DefIdTree, ExistentialPredicate, FloatVar, FloatVid, GenericParamDefKind, InferConst, InferTy,
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IntVar, IntVid, List, ParamConst, ParamTy, PolyFnSig, Predicate, PredicateKind, ProjectionTy,
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Region, RegionKind, ReprOptions, TraitObjectVisitor, Ty, TyKind, TyS, TyVar, TyVid, TypeAndMut,
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};
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use rustc_ast::ast;
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use rustc_ast::expand::allocator::AllocatorKind;
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use rustc_attr as attr;
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@ -48,10 +37,8 @@
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use rustc_hir::def::{DefKind, Res};
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use rustc_hir::def_id::{CrateNum, DefId, DefIdMap, DefIdSet, LocalDefId, LOCAL_CRATE};
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use rustc_hir::definitions::{DefPathHash, Definitions};
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use rustc_hir::lang_items;
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use rustc_hir::lang_items::PanicLocationLangItem;
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use rustc_hir::{HirId, Node, TraitCandidate};
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use rustc_hir::{ItemKind, ItemLocalId, ItemLocalMap, ItemLocalSet};
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use rustc_hir::lang_items::{self, PanicLocationLangItem};
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use rustc_hir::{HirId, ItemKind, ItemLocalId, ItemLocalMap, ItemLocalSet, Node, TraitCandidate};
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use rustc_index::vec::{Idx, IndexVec};
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use rustc_macros::HashStable;
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use rustc_session::config::{BorrowckMode, CrateType, OutputFilenames};
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@ -1396,6 +1383,66 @@ pub fn is_suitable_region(&self, region: Region<'tcx>) -> Option<FreeRegionInfo>
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})
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}
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pub fn return_type_impl_or_dyn_trait(&self, scope_def_id: DefId) -> Option<(Span, bool)> {
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let hir_id = self.hir().as_local_hir_id(scope_def_id.expect_local());
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let hir_output = match self.hir().get(hir_id) {
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Node::Item(hir::Item {
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kind:
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ItemKind::Fn(
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hir::FnSig {
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decl: hir::FnDecl { output: hir::FnRetTy::Return(ty), .. },
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..
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},
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..,
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),
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..
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})
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| Node::ImplItem(hir::ImplItem {
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kind:
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hir::ImplItemKind::Fn(
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hir::FnSig {
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decl: hir::FnDecl { output: hir::FnRetTy::Return(ty), .. },
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..
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},
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_,
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),
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..
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})
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| Node::TraitItem(hir::TraitItem {
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kind:
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hir::TraitItemKind::Fn(
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hir::FnSig {
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decl: hir::FnDecl { output: hir::FnRetTy::Return(ty), .. },
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..
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},
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_,
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),
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..
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}) => ty,
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_ => return None,
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};
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let ret_ty = self.type_of(scope_def_id);
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match ret_ty.kind {
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ty::FnDef(_, _) => {
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let sig = ret_ty.fn_sig(*self);
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let output = self.erase_late_bound_regions(&sig.output());
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if output.is_impl_trait() {
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let fn_decl = self.hir().fn_decl_by_hir_id(hir_id).unwrap();
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Some((fn_decl.output.span(), false))
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} else {
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let mut v = TraitObjectVisitor(vec![]);
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rustc_hir::intravisit::walk_ty(&mut v, hir_output);
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if v.0.len() == 1 {
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return Some((v.0[0], true));
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}
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None
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}
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}
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_ => None,
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}
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}
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pub fn return_type_impl_trait(&self, scope_def_id: DefId) -> Option<(Ty<'tcx>, Span)> {
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// HACK: `type_of_def_id()` will fail on these (#55796), so return `None`.
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let hir_id = self.hir().as_local_hir_id(scope_def_id.expect_local());
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@ -249,3 +249,22 @@ pub fn suggest_constraining_type_param(
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true
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}
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}
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pub struct TraitObjectVisitor(pub Vec<rustc_span::Span>);
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impl<'v> hir::intravisit::Visitor<'v> for TraitObjectVisitor {
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type Map = rustc_hir::intravisit::ErasedMap<'v>;
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fn nested_visit_map(&mut self) -> hir::intravisit::NestedVisitorMap<Self::Map> {
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hir::intravisit::NestedVisitorMap::None
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}
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fn visit_ty(&mut self, ty: &hir::Ty<'_>) {
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if let hir::TyKind::TraitObject(
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_,
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hir::Lifetime { name: hir::LifetimeName::ImplicitObjectLifetimeDefault, .. },
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) = ty.kind
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{
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self.0.push(ty.span);
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}
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}
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}
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|
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@ -4,7 +4,7 @@ error: cannot infer an appropriate lifetime
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LL | pub async fn run_dummy_fn(&self) {
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| ^^^^^ ...but this borrow...
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LL | foo(|| self.bar()).await;
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| --- this return type evaluates to the `'static` lifetime...
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| --- this evaluates to the `'static` lifetime...
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|
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note: ...can't outlive the lifetime `'_` as defined on the method body at 12:31
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--> $DIR/issue-62097.rs:12:31
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|
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@ -4,17 +4,17 @@ error: cannot infer an appropriate lifetime
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LL | fn elided(x: &i32) -> impl Copy { x }
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| --------- ^ ...but this borrow...
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| |
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| this return type evaluates to the `'static` lifetime...
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| this evaluates to the `'static` lifetime...
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|
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note: ...can't outlive the anonymous lifetime #1 defined on the function body at 3:1
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--> $DIR/must_outlive_least_region_or_bound.rs:3:1
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|
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LL | fn elided(x: &i32) -> impl Copy { x }
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| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
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help: you can add a bound to the return type to make it last less than `'static` and match the anonymous lifetime #1 defined on the function body at 3:1
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help: you can add a bound to the returned `impl Trait` to make it last less than `'static` and match the anonymous lifetime #1 defined on the function body at 3:1
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|
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LL | fn elided(x: &i32) -> impl Copy + '_ { x }
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| ^^^^^^^^^^^^^^
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| ^^^^
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error: cannot infer an appropriate lifetime
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--> $DIR/must_outlive_least_region_or_bound.rs:6:44
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@ -22,17 +22,17 @@ error: cannot infer an appropriate lifetime
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LL | fn explicit<'a>(x: &'a i32) -> impl Copy { x }
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| --------- ^ ...but this borrow...
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| |
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| this return type evaluates to the `'static` lifetime...
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| this evaluates to the `'static` lifetime...
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|
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note: ...can't outlive the lifetime `'a` as defined on the function body at 6:13
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--> $DIR/must_outlive_least_region_or_bound.rs:6:13
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|
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LL | fn explicit<'a>(x: &'a i32) -> impl Copy { x }
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| ^^
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help: you can add a bound to the return type to make it last less than `'static` and match the lifetime `'a` as defined on the function body at 6:13
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help: you can add a bound to the returned `impl Trait` to make it last less than `'static` and match the lifetime `'a` as defined on the function body at 6:13
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|
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LL | fn explicit<'a>(x: &'a i32) -> impl Copy + 'a { x }
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| ^^^^^^^^^^^^^^
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| ^^^^
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error: cannot infer an appropriate lifetime
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--> $DIR/must_outlive_least_region_or_bound.rs:12:69
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@ -40,17 +40,17 @@ error: cannot infer an appropriate lifetime
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LL | fn with_bound<'a>(x: &'a i32) -> impl LifetimeTrait<'a> + 'static { x }
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| -------------------------------- ^ ...but this borrow...
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| |
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| this return type evaluates to the `'static` lifetime...
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| this evaluates to the `'static` lifetime...
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|
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note: ...can't outlive the lifetime `'a` as defined on the function body at 12:15
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--> $DIR/must_outlive_least_region_or_bound.rs:12:15
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|
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LL | fn with_bound<'a>(x: &'a i32) -> impl LifetimeTrait<'a> + 'static { x }
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| ^^
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help: you can add a bound to the return type to make it last less than `'static` and match the lifetime `'a` as defined on the function body at 12:15
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help: you can add a bound to the returned `impl Trait` to make it last less than `'static` and match the lifetime `'a` as defined on the function body at 12:15
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|
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LL | fn with_bound<'a>(x: &'a i32) -> impl LifetimeTrait<'a> + 'static + 'a { x }
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| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
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| ^^^^
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error[E0623]: lifetime mismatch
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--> $DIR/must_outlive_least_region_or_bound.rs:17:61
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|
|
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@ -2,7 +2,7 @@ error: cannot infer an appropriate lifetime
|
|||
--> $DIR/static-return-lifetime-infered.rs:7:16
|
||||
|
|
||||
LL | fn iter_values_anon(&self) -> impl Iterator<Item=u32> {
|
||||
| ----------------------- this return type evaluates to the `'static` lifetime...
|
||||
| ----------------------- this evaluates to the `'static` lifetime...
|
||||
LL | self.x.iter().map(|a| a.0)
|
||||
| ------ ^^^^
|
||||
| |
|
||||
|
|
@ -15,16 +15,16 @@ LL | / fn iter_values_anon(&self) -> impl Iterator<Item=u32> {
|
|||
LL | | self.x.iter().map(|a| a.0)
|
||||
LL | | }
|
||||
| |_____^
|
||||
help: you can add a bound to the return type to make it last less than `'static` and match the anonymous lifetime #1 defined on the method body at 6:5
|
||||
help: you can add a bound to the returned `impl Trait` to make it last less than `'static` and match the anonymous lifetime #1 defined on the method body at 6:5
|
||||
|
|
||||
LL | fn iter_values_anon(&self) -> impl Iterator<Item=u32> + '_ {
|
||||
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
||||
| ^^^^
|
||||
|
||||
error: cannot infer an appropriate lifetime
|
||||
--> $DIR/static-return-lifetime-infered.rs:11:16
|
||||
|
|
||||
LL | fn iter_values<'a>(&'a self) -> impl Iterator<Item=u32> {
|
||||
| ----------------------- this return type evaluates to the `'static` lifetime...
|
||||
| ----------------------- this evaluates to the `'static` lifetime...
|
||||
LL | self.x.iter().map(|a| a.0)
|
||||
| ------ ^^^^
|
||||
| |
|
||||
|
|
@ -35,10 +35,10 @@ note: ...can't outlive the lifetime `'a` as defined on the method body at 10:20
|
|||
|
|
||||
LL | fn iter_values<'a>(&'a self) -> impl Iterator<Item=u32> {
|
||||
| ^^
|
||||
help: you can add a bound to the return type to make it last less than `'static` and match the lifetime `'a` as defined on the method body at 10:20
|
||||
help: you can add a bound to the returned `impl Trait` to make it last less than `'static` and match the lifetime `'a` as defined on the method body at 10:20
|
||||
|
|
||||
LL | fn iter_values<'a>(&'a self) -> impl Iterator<Item=u32> + 'a {
|
||||
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
||||
| ^^^^
|
||||
|
||||
error: aborting due to 2 previous errors
|
||||
|
||||
|
|
|
|||
|
|
@ -2,7 +2,7 @@
|
|||
|
||||
fn foo<T: Any>(value: &T) -> Box<dyn Any> {
|
||||
Box::new(value) as Box<dyn Any>
|
||||
//~^ ERROR explicit lifetime required in the type of `value` [E0621]
|
||||
//~^ ERROR cannot infer an appropriate lifetime
|
||||
}
|
||||
|
||||
fn main() {
|
||||
|
|
|
|||
|
|
@ -1,11 +1,24 @@
|
|||
error[E0621]: explicit lifetime required in the type of `value`
|
||||
--> $DIR/issue-16922.rs:4:5
|
||||
error: cannot infer an appropriate lifetime
|
||||
--> $DIR/issue-16922.rs:4:14
|
||||
|
|
||||
LL | fn foo<T: Any>(value: &T) -> Box<dyn Any> {
|
||||
| -- help: add explicit lifetime `'static` to the type of `value`: `&'static T`
|
||||
LL | Box::new(value) as Box<dyn Any>
|
||||
| ^^^^^^^^^^^^^^^ lifetime `'static` required
|
||||
| ---------^^^^^-
|
||||
| | |
|
||||
| | ...but this borrow...
|
||||
| this evaluates to the `'static` lifetime...
|
||||
|
|
||||
note: ...can't outlive the anonymous lifetime #1 defined on the function body at 3:1
|
||||
--> $DIR/issue-16922.rs:3:1
|
||||
|
|
||||
LL | / fn foo<T: Any>(value: &T) -> Box<dyn Any> {
|
||||
LL | | Box::new(value) as Box<dyn Any>
|
||||
LL | |
|
||||
LL | | }
|
||||
| |_^
|
||||
help: you can add a bound to the returned `dyn Trait` to make it last less than `'static` and match the anonymous lifetime #1 defined on the function body at 3:1
|
||||
|
|
||||
LL | fn foo<T: Any>(value: &T) -> Box<dyn Any + '_> {
|
||||
| ^^^^
|
||||
|
||||
error: aborting due to previous error
|
||||
|
||||
For more information about this error, try `rustc --explain E0621`.
|
||||
|
|
|
|||
|
|
@ -15,7 +15,7 @@ fn load(ss: &mut SomeStruct) -> Box<dyn SomeTrait> {
|
|||
// `Box<SomeTrait>` defaults to a `'static` bound, so this return
|
||||
// is illegal.
|
||||
|
||||
ss.r //~ ERROR explicit lifetime required in the type of `ss` [E0621]
|
||||
ss.r //~ ERROR cannot infer an appropriate lifetime
|
||||
}
|
||||
|
||||
fn store(ss: &mut SomeStruct, b: Box<dyn SomeTrait>) {
|
||||
|
|
|
|||
|
|
@ -1,11 +1,26 @@
|
|||
error[E0621]: explicit lifetime required in the type of `ss`
|
||||
error: cannot infer an appropriate lifetime
|
||||
--> $DIR/object-lifetime-default-from-box-error.rs:18:5
|
||||
|
|
||||
LL | fn load(ss: &mut SomeStruct) -> Box<dyn SomeTrait> {
|
||||
| --------------- help: add explicit lifetime `'static` to the type of `ss`: `&mut SomeStruct<'static>`
|
||||
...
|
||||
LL | ss.r
|
||||
| ^^^^ lifetime `'static` required
|
||||
| ^^^^
|
||||
| |
|
||||
| this evaluates to the `'static` lifetime...
|
||||
| ...but this borrow...
|
||||
|
|
||||
note: ...can't outlive the anonymous lifetime #2 defined on the function body at 14:1
|
||||
--> $DIR/object-lifetime-default-from-box-error.rs:14:1
|
||||
|
|
||||
LL | / fn load(ss: &mut SomeStruct) -> Box<dyn SomeTrait> {
|
||||
LL | | // `Box<SomeTrait>` defaults to a `'static` bound, so this return
|
||||
LL | | // is illegal.
|
||||
LL | |
|
||||
LL | | ss.r
|
||||
LL | | }
|
||||
| |_^
|
||||
help: you can add a bound to the returned `dyn Trait` to make it last less than `'static` and match the anonymous lifetime #2 defined on the function body at 14:1
|
||||
|
|
||||
LL | fn load(ss: &mut SomeStruct) -> Box<dyn SomeTrait + '_> {
|
||||
| ^^^^
|
||||
|
||||
error[E0621]: explicit lifetime required in the type of `ss`
|
||||
--> $DIR/object-lifetime-default-from-box-error.rs:31:12
|
||||
|
|
|
|||
|
|
@ -11,20 +11,17 @@ fn a(v: &[u8]) -> Box<dyn Foo + 'static> {
|
|||
}
|
||||
|
||||
fn b(v: &[u8]) -> Box<dyn Foo + 'static> {
|
||||
Box::new(v)
|
||||
//~^ ERROR explicit lifetime required in the type of `v` [E0621]
|
||||
Box::new(v) //~ ERROR explicit lifetime required in the type of `v` [E0621]
|
||||
}
|
||||
|
||||
fn c(v: &[u8]) -> Box<dyn Foo> {
|
||||
// same as previous case due to RFC 599
|
||||
|
||||
Box::new(v)
|
||||
//~^ ERROR explicit lifetime required in the type of `v` [E0621]
|
||||
Box::new(v) //~ ERROR cannot infer an appropriate lifetime
|
||||
}
|
||||
|
||||
fn d<'a,'b>(v: &'a [u8]) -> Box<dyn Foo+'b> {
|
||||
Box::new(v)
|
||||
//~^ ERROR cannot infer an appropriate lifetime due to conflicting
|
||||
Box::new(v) //~ ERROR cannot infer an appropriate lifetime due to conflicting
|
||||
}
|
||||
|
||||
fn e<'a:'b,'b>(v: &'a [u8]) -> Box<dyn Foo+'b> {
|
||||
|
|
|
|||
|
|
@ -14,40 +14,54 @@ LL | fn b(v: &[u8]) -> Box<dyn Foo + 'static> {
|
|||
LL | Box::new(v)
|
||||
| ^^^^^^^^^^^ lifetime `'static` required
|
||||
|
||||
error[E0621]: explicit lifetime required in the type of `v`
|
||||
--> $DIR/region-object-lifetime-in-coercion.rs:21:5
|
||||
error: cannot infer an appropriate lifetime
|
||||
--> $DIR/region-object-lifetime-in-coercion.rs:20:14
|
||||
|
|
||||
LL | fn c(v: &[u8]) -> Box<dyn Foo> {
|
||||
| ----- help: add explicit lifetime `'static` to the type of `v`: `&'static [u8]`
|
||||
...
|
||||
LL | Box::new(v)
|
||||
| ^^^^^^^^^^^ lifetime `'static` required
|
||||
| ---------^-
|
||||
| | |
|
||||
| | ...but this borrow...
|
||||
| this evaluates to the `'static` lifetime...
|
||||
|
|
||||
note: ...can't outlive the anonymous lifetime #1 defined on the function body at 17:1
|
||||
--> $DIR/region-object-lifetime-in-coercion.rs:17:1
|
||||
|
|
||||
LL | / fn c(v: &[u8]) -> Box<dyn Foo> {
|
||||
LL | | // same as previous case due to RFC 599
|
||||
LL | |
|
||||
LL | | Box::new(v)
|
||||
LL | | }
|
||||
| |_^
|
||||
help: you can add a bound to the returned `dyn Trait` to make it last less than `'static` and match the anonymous lifetime #1 defined on the function body at 17:1
|
||||
|
|
||||
LL | fn c(v: &[u8]) -> Box<dyn Foo + '_> {
|
||||
| ^^^^
|
||||
|
||||
error[E0495]: cannot infer an appropriate lifetime due to conflicting requirements
|
||||
--> $DIR/region-object-lifetime-in-coercion.rs:26:14
|
||||
--> $DIR/region-object-lifetime-in-coercion.rs:24:14
|
||||
|
|
||||
LL | Box::new(v)
|
||||
| ^
|
||||
|
|
||||
note: first, the lifetime cannot outlive the lifetime `'a` as defined on the function body at 25:6...
|
||||
--> $DIR/region-object-lifetime-in-coercion.rs:25:6
|
||||
note: first, the lifetime cannot outlive the lifetime `'a` as defined on the function body at 23:6...
|
||||
--> $DIR/region-object-lifetime-in-coercion.rs:23:6
|
||||
|
|
||||
LL | fn d<'a,'b>(v: &'a [u8]) -> Box<dyn Foo+'b> {
|
||||
| ^^
|
||||
note: ...so that the expression is assignable
|
||||
--> $DIR/region-object-lifetime-in-coercion.rs:26:14
|
||||
--> $DIR/region-object-lifetime-in-coercion.rs:24:14
|
||||
|
|
||||
LL | Box::new(v)
|
||||
| ^
|
||||
= note: expected `&[u8]`
|
||||
found `&'a [u8]`
|
||||
note: but, the lifetime must be valid for the lifetime `'b` as defined on the function body at 25:9...
|
||||
--> $DIR/region-object-lifetime-in-coercion.rs:25:9
|
||||
note: but, the lifetime must be valid for the lifetime `'b` as defined on the function body at 23:9...
|
||||
--> $DIR/region-object-lifetime-in-coercion.rs:23:9
|
||||
|
|
||||
LL | fn d<'a,'b>(v: &'a [u8]) -> Box<dyn Foo+'b> {
|
||||
| ^^
|
||||
note: ...so that the expression is assignable
|
||||
--> $DIR/region-object-lifetime-in-coercion.rs:26:5
|
||||
--> $DIR/region-object-lifetime-in-coercion.rs:24:5
|
||||
|
|
||||
LL | Box::new(v)
|
||||
| ^^^^^^^^^^^
|
||||
|
|
|
|||
|
|
@ -2,7 +2,7 @@ error: cannot infer an appropriate lifetime
|
|||
--> $DIR/arbitrary_self_types_pin_lifetime_impl_trait-async.rs:8:16
|
||||
|
|
||||
LL | async fn f(self: Pin<&Self>) -> impl Clone { self }
|
||||
| ^^^^ ---------- this return type evaluates to the `'static` lifetime...
|
||||
| ^^^^ ---------- this evaluates to the `'static` lifetime...
|
||||
| |
|
||||
| ...but this borrow...
|
||||
|
|
||||
|
|
|
|||
|
|
@ -4,17 +4,17 @@ error: cannot infer an appropriate lifetime
|
|||
LL | fn f(self: Pin<&Self>) -> impl Clone { self }
|
||||
| ---------- ^^^^ ...but this borrow...
|
||||
| |
|
||||
| this return type evaluates to the `'static` lifetime...
|
||||
| this evaluates to the `'static` lifetime...
|
||||
|
|
||||
note: ...can't outlive the anonymous lifetime #1 defined on the method body at 6:5
|
||||
--> $DIR/arbitrary_self_types_pin_lifetime_impl_trait.rs:6:5
|
||||
|
|
||||
LL | fn f(self: Pin<&Self>) -> impl Clone { self }
|
||||
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
||||
help: you can add a bound to the return type to make it last less than `'static` and match the anonymous lifetime #1 defined on the method body at 6:5
|
||||
help: you can add a bound to the returned `impl Trait` to make it last less than `'static` and match the anonymous lifetime #1 defined on the method body at 6:5
|
||||
|
|
||||
LL | fn f(self: Pin<&Self>) -> impl Clone + '_ { self }
|
||||
| ^^^^^^^^^^^^^^^
|
||||
| ^^^^
|
||||
|
||||
error: aborting due to previous error
|
||||
|
||||
|
|
|
|||
|
|
@ -10,7 +10,7 @@ error: cannot infer an appropriate lifetime
|
|||
--> $DIR/missing-lifetimes-in-signature.rs:19:5
|
||||
|
|
||||
LL | fn foo<G, T>(g: G, dest: &mut T) -> impl FnOnce()
|
||||
| ------------- this return type evaluates to the `'static` lifetime...
|
||||
| ------------- this evaluates to the `'static` lifetime...
|
||||
...
|
||||
LL | / move || {
|
||||
LL | | *dest = g.get();
|
||||
|
|
@ -28,10 +28,10 @@ LL | | {
|
|||
LL | | }
|
||||
LL | | }
|
||||
| |_^
|
||||
help: you can add a bound to the return type to make it last less than `'static` and match the anonymous lifetime #1 defined on the function body at 15:1
|
||||
help: you can add a bound to the returned `impl Trait` to make it last less than `'static` and match the anonymous lifetime #1 defined on the function body at 15:1
|
||||
|
|
||||
LL | fn foo<G, T>(g: G, dest: &mut T) -> impl FnOnce() + '_
|
||||
| ^^^^^^^^^^^^^^^^^^
|
||||
| ^^^^
|
||||
|
||||
error[E0311]: the parameter type `G` may not live long enough
|
||||
--> $DIR/missing-lifetimes-in-signature.rs:25:37
|
||||
|
|
|
|||
|
|
@ -5,7 +5,7 @@
|
|||
|
||||
fn a<T>(items: &[T]) -> Box<dyn Iterator<Item=&T>> {
|
||||
// ^^^^^^^^^^^^^^^^^^^^^ bound *here* defaults to `'static`
|
||||
Box::new(items.iter()) //~ ERROR explicit lifetime required in the type of `items`
|
||||
Box::new(items.iter()) //~ ERROR cannot infer an appropriate lifetime
|
||||
}
|
||||
|
||||
fn b<T>(items: &[T]) -> Box<dyn Iterator<Item=&T> + '_> {
|
||||
|
|
|
|||
|
|
@ -1,12 +1,24 @@
|
|||
error[E0621]: explicit lifetime required in the type of `items`
|
||||
--> $DIR/dyn-trait-underscore.rs:8:5
|
||||
error: cannot infer an appropriate lifetime
|
||||
--> $DIR/dyn-trait-underscore.rs:8:20
|
||||
|
|
||||
LL | fn a<T>(items: &[T]) -> Box<dyn Iterator<Item=&T>> {
|
||||
| ---- help: add explicit lifetime `'static` to the type of `items`: `&'static [T]`
|
||||
LL | // ^^^^^^^^^^^^^^^^^^^^^ bound *here* defaults to `'static`
|
||||
LL | Box::new(items.iter())
|
||||
| ^^^^^^^^^^^^^^^^^^^^^^ lifetime `'static` required
|
||||
| ---------------^^^^---
|
||||
| | |
|
||||
| | ...but this borrow...
|
||||
| this evaluates to the `'static` lifetime...
|
||||
|
|
||||
note: ...can't outlive the anonymous lifetime #1 defined on the function body at 6:1
|
||||
--> $DIR/dyn-trait-underscore.rs:6:1
|
||||
|
|
||||
LL | / fn a<T>(items: &[T]) -> Box<dyn Iterator<Item=&T>> {
|
||||
LL | | // ^^^^^^^^^^^^^^^^^^^^^ bound *here* defaults to `'static`
|
||||
LL | | Box::new(items.iter())
|
||||
LL | | }
|
||||
| |_^
|
||||
help: you can add a bound to the returned `dyn Trait` to make it last less than `'static` and match the anonymous lifetime #1 defined on the function body at 6:1
|
||||
|
|
||||
LL | fn a<T>(items: &[T]) -> Box<dyn Iterator<Item=&T> + '_> {
|
||||
| ^^^^
|
||||
|
||||
error: aborting due to previous error
|
||||
|
||||
For more information about this error, try `rustc --explain E0621`.
|
||||
|
|
|
|||
Loading…
Reference in a new issue