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Rollup merge of #89734 - estebank:issue-72312, r=nikomatsakis

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Point at capture points for non-`'static` reference crossing a `yield` point

```
error[E0759]: `self` has an anonymous lifetime `'_` but it needs to satisfy a `'static` lifetime requirement
  --> $DIR/issue-72312.rs:10:24
   |
LL |     pub async fn start(&self) {
   |                        ^^^^^ this data with an anonymous lifetime `'_`...
...
LL |         require_static(async move {
   |         -------------- ...is required to live as long as `'static` here...
LL |             &self;
   |             ----- ...and is captured here
   |
note: `'static` lifetime requirement introduced by this trait bound
  --> $DIR/issue-72312.rs:2:22
   |
LL | fn require_static<T: 'static>(val: T) -> T {
   |                      ^^^^^^^

error: aborting due to previous error

For more information about this error, try `rustc --explain E0759`.
```

Fix #72312.
This commit is contained in:
Matthias Krüger 2021-12-11 17:35:23 +01:00 committed by GitHub
commit 7bba5c163c
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
37 changed files with 467 additions and 134 deletions
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1
compiler/rustc_borrowck/src/diagnostics/bound_region_errors.rs
View File

@ -368,6 +368,7 @@ fn try_extract_error_from_fulfill_cx<'tcx>(
error_region,
cause.clone(),
placeholder_region,
vec![],
),
),
(Some(error_region), _) => NiceRegionError::new(

3
compiler/rustc_infer/src/infer/error_reporting/mod.rs
View File

@ -384,6 +384,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
sub_r,
sup_origin,
sup_r,
_,
) => {
if sub_r.is_placeholder() {
self.report_placeholder_failure(sub_origin, sub_r, sup_r).emit();
@ -464,7 +465,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
errors.sort_by_key(|u| match *u {
RegionResolutionError::ConcreteFailure(ref sro, _, _) => sro.span(),
RegionResolutionError::GenericBoundFailure(ref sro, _, _) => sro.span(),
RegionResolutionError::SubSupConflict(_, ref rvo, _, _, _, _) => rvo.span(),
RegionResolutionError::SubSupConflict(_, ref rvo, _, _, _, _, _) => rvo.span(),
RegionResolutionError::UpperBoundUniverseConflict(_, ref rvo, _, _, _) => rvo.span(),
});
errors

2
compiler/rustc_infer/src/infer/error_reporting/nice_region_error/mod.rs
View File

@ -67,7 +67,7 @@ impl<'cx, 'tcx> NiceRegionError<'cx, 'tcx> {
pub fn regions(&self) -> Option<(Span, ty::Region<'tcx>, ty::Region<'tcx>)> {
match (&self.error, self.regions) {
(Some(ConcreteFailure(origin, sub, sup)), None) => Some((origin.span(), sub, sup)),
(Some(SubSupConflict(_, _, origin, sub, _, sup)), None) => {
(Some(SubSupConflict(_, _, origin, sub, _, sup, _)), None) => {
Some((origin.span(), sub, sup))
}
(None, Some((span, sub, sup))) => Some((span, sub, sup)),

4
compiler/rustc_infer/src/infer/error_reporting/nice_region_error/placeholder_error.rs
View File

@ -34,6 +34,7 @@ impl NiceRegionError<'me, 'tcx> {
sub_placeholder @ ty::RePlaceholder(_),
_,
sup_placeholder @ ty::RePlaceholder(_),
_,
)) => self.try_report_trait_placeholder_mismatch(
Some(self.tcx().mk_region(ty::ReVar(*vid))),
cause,
@ -49,6 +50,7 @@ impl NiceRegionError<'me, 'tcx> {
sub_placeholder @ ty::RePlaceholder(_),
_,
_,
_,
)) => self.try_report_trait_placeholder_mismatch(
Some(self.tcx().mk_region(ty::ReVar(*vid))),
cause,
@ -64,6 +66,7 @@ impl NiceRegionError<'me, 'tcx> {
_,
_,
sup_placeholder @ ty::RePlaceholder(_),
_,
)) => self.try_report_trait_placeholder_mismatch(
Some(self.tcx().mk_region(ty::ReVar(*vid))),
cause,
@ -79,6 +82,7 @@ impl NiceRegionError<'me, 'tcx> {
_,
SubregionOrigin::Subtype(box TypeTrace { cause, values }),
sup_placeholder @ ty::RePlaceholder(_),
_,
)) => self.try_report_trait_placeholder_mismatch(
Some(self.tcx().mk_region(ty::ReVar(*vid))),
cause,

141
compiler/rustc_infer/src/infer/error_reporting/nice_region_error/static_impl_trait.rs
View File

@ -10,7 +10,8 @@ use rustc_hir::def_id::DefId;
use rustc_hir::intravisit::{walk_ty, ErasedMap, NestedVisitorMap, Visitor};
use rustc_hir::{self as hir, GenericBound, Item, ItemKind, Lifetime, LifetimeName, Node, TyKind};
use rustc_middle::ty::{
self, AssocItemContainer, RegionKind, Ty, TyCtxt, TypeFoldable, TypeVisitor,
self, AssocItemContainer, RegionKind, StaticLifetimeVisitor, Ty, TyCtxt, TypeFoldable,
TypeVisitor,
};
use rustc_span::symbol::Ident;
use rustc_span::{MultiSpan, Span};
@ -23,7 +24,7 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
pub(super) fn try_report_static_impl_trait(&self) -> Option<ErrorReported> {
debug!("try_report_static_impl_trait(error={:?})", self.error);
let tcx = self.tcx();
let (var_origin, sub_origin, sub_r, sup_origin, sup_r) = match self.error.as_ref()? {
let (var_origin, sub_origin, sub_r, sup_origin, sup_r, spans) = match self.error.as_ref()? {
RegionResolutionError::SubSupConflict(
_,
var_origin,
@ -31,8 +32,9 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
sub_r,
sup_origin,
sup_r,
spans,
) if **sub_r == RegionKind::ReStatic => {
(var_origin, sub_origin, sub_r, sup_origin, sup_r)
(var_origin, sub_origin, sub_r, sup_origin, sup_r, spans)
}
RegionResolutionError::ConcreteFailure(
SubregionOrigin::Subtype(box TypeTrace { cause, .. }),
@ -74,7 +76,7 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
err.span_label(
cause.span,
&format!(
"...is captured and required to live as long as `'static` here \
"...is used and required to live as long as `'static` here \
because of an implicit lifetime bound on the {}",
match ctxt.assoc_item.container {
AssocItemContainer::TraitContainer(id) =>
@ -123,56 +125,101 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
param_name,
lifetime,
);
err.span_label(param.param_ty_span, &format!("this data with {}...", lifetime));
let (mention_influencer, influencer_point) =
if sup_origin.span().overlaps(param.param_ty_span) {
// Account for `async fn` like in `async-await/issues/issue-62097.rs`.
// The desugaring of `async `fn`s causes `sup_origin` and `param` to point at the same
// place (but with different `ctxt`, hence `overlaps` instead of `==` above).
//
// This avoids the following:
//
// LL | pub async fn run_dummy_fn(&self) {
// | ^^^^^
// | |
// | this data with an anonymous lifetime `'_`...
// | ...is captured here...
(false, sup_origin.span())
} else {
(!sup_origin.span().overlaps(return_sp), param.param_ty_span)
};
err.span_label(influencer_point, &format!("this data with {}...", lifetime));
debug!("try_report_static_impl_trait: param_info={:?}", param);
// We try to make the output have fewer overlapping spans if possible.
if (sp == sup_origin.span() || !return_sp.overlaps(sup_origin.span()))
&& sup_origin.span() != return_sp
{
// FIXME: account for `async fn` like in `async-await/issues/issue-62097.rs`
let mut spans = spans.clone();
// Customize the spans and labels depending on their relative order so
// that split sentences flow correctly.
if sup_origin.span().overlaps(return_sp) && sp == sup_origin.span() {
// Avoid the following:
//
// error: cannot infer an appropriate lifetime
// --> $DIR/must_outlive_least_region_or_bound.rs:18:50
// |
// LL | fn foo(x: &i32) -> Box<dyn Debug> { Box::new(x) }
// | ---- ---------^-
//
// and instead show:
//
// error: cannot infer an appropriate lifetime
// --> $DIR/must_outlive_least_region_or_bound.rs:18:50
// |
// LL | fn foo(x: &i32) -> Box<dyn Debug> { Box::new(x) }
// | ---- ^
err.span_label(
sup_origin.span(),
"...is captured here, requiring it to live as long as `'static`",
);
} else {
err.span_label(sup_origin.span(), "...is captured here...");
if return_sp < sup_origin.span() {
err.span_note(
return_sp,
"...and is required to live as long as `'static` here",
if mention_influencer {
spans.push(sup_origin.span());
}
// We dedup the spans *ignoring* expansion context.
spans.sort();
spans.dedup_by_key(|span| (span.lo(), span.hi()));
// We try to make the output have fewer overlapping spans if possible.
let require_msg = if spans.is_empty() {
"...is used and required to live as long as `'static` here"
} else {
"...and is required to live as long as `'static` here"
};
let require_span =
if sup_origin.span().overlaps(return_sp) { sup_origin.span() } else { return_sp };
for span in &spans {
err.span_label(*span, "...is used here...");
}
if spans.iter().any(|sp| sp.overlaps(return_sp) || *sp > return_sp) {
// If any of the "captured here" labels appears on the same line or after
// `require_span`, we put it on a note to ensure the text flows by appearing
// always at the end.
err.span_note(require_span, require_msg);
} else {
// We don't need a note, it's already at the end, it can be shown as a `span_label`.
err.span_label(require_span, require_msg);
}
if let SubregionOrigin::RelateParamBound(_, _, Some(bound)) = sub_origin {
err.span_note(*bound, "`'static` lifetime requirement introduced by this bound");
}
if let SubregionOrigin::Subtype(box TypeTrace { cause, .. }) = sub_origin {
if let ObligationCauseCode::ReturnValue(hir_id)
| ObligationCauseCode::BlockTailExpression(hir_id) = &cause.code
{
let parent_id = tcx.hir().get_parent_item(*hir_id);
if let Some(fn_decl) = tcx.hir().fn_decl_by_hir_id(parent_id) {
let mut span: MultiSpan = fn_decl.output.span().into();
let mut add_label = true;
if let hir::FnRetTy::Return(ty) = fn_decl.output {
let mut v = StaticLifetimeVisitor(vec![], tcx.hir());
v.visit_ty(ty);
if !v.0.is_empty() {
span = v.0.clone().into();
for sp in v.0 {
span.push_span_label(
sp,
"`'static` requirement introduced here".to_string(),
);
}
add_label = false;
}
}
if add_label {
span.push_span_label(
fn_decl.output.span(),
"requirement introduced by this return type".to_string(),
);
}
span.push_span_label(
cause.span,
"because of this returned expression".to_string(),
);
} else {
err.span_label(
return_sp,
"...and is required to live as long as `'static` here",
err.span_note(
span,
"`'static` lifetime requirement introduced by the return type",
);
}
}
} else {
err.span_label(
return_sp,
"...is captured and required to live as long as `'static` here",
);
}
let fn_returns = tcx.return_type_impl_or_dyn_traits(anon_reg_sup.def_id);

1
compiler/rustc_infer/src/infer/error_reporting/nice_region_error/trait_impl_difference.rs
View File

@ -28,6 +28,7 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
_sub,
sup_origin,
_sup,
_,
) = error.clone()
{
if let (&Subtype(ref sup_trace), &Subtype(ref sub_trace)) = (&sup_origin, &sub_origin) {

30
compiler/rustc_infer/src/infer/lexical_region_resolve/mod.rs
View File

@ -19,6 +19,7 @@ use rustc_middle::ty::{self, Ty, TyCtxt};
use rustc_middle::ty::{ReEarlyBound, ReEmpty, ReErased, ReFree, ReStatic};
use rustc_middle::ty::{ReLateBound, RePlaceholder, ReVar};
use rustc_middle::ty::{Region, RegionVid};
use rustc_span::Span;
use std::fmt;
/// This function performs lexical region resolution given a complete
@ -96,6 +97,7 @@ pub enum RegionResolutionError<'tcx> {
Region<'tcx>,
SubregionOrigin<'tcx>,
Region<'tcx>,
Vec<Span>, // All the influences on a given value that didn't meet its constraints.
),
/// Indicates a `'b: 'a` constraint where `'a` is in a universe that
@ -567,7 +569,30 @@ impl<'cx, 'tcx> LexicalResolver<'cx, 'tcx> {
// if this rule starts to create problems we'll
// have to revisit this portion of the code and
// think hard about it. =) -- nikomatsakis
self.collect_error_for_expanding_node(graph, &mut dup_vec, node_vid, errors);
// Obtain the spans for all the places that can
// influence the constraints on this value for
// richer diagnostics in `static_impl_trait`.
let influences: Vec<Span> = self
.data
.constraints
.iter()
.filter_map(|(constraint, origin)| match (constraint, origin) {
(
Constraint::VarSubVar(_, sup),
SubregionOrigin::DataBorrowed(_, sp),
) if sup == &node_vid => Some(*sp),
_ => None,
})
.collect();
self.collect_error_for_expanding_node(
graph,
&mut dup_vec,
node_vid,
errors,
influences,
);
}
}
}
@ -621,6 +646,7 @@ impl<'cx, 'tcx> LexicalResolver<'cx, 'tcx> {
dup_vec: &mut IndexVec<RegionVid, Option<RegionVid>>,
node_idx: RegionVid,
errors: &mut Vec<RegionResolutionError<'tcx>>,
influences: Vec<Span>,
) {
// Errors in expanding nodes result from a lower-bound that is
// not contained by an upper-bound.
@ -667,6 +693,7 @@ impl<'cx, 'tcx> LexicalResolver<'cx, 'tcx> {
sup: {:?}",
origin, node_idx, lower_bound.region, upper_bound.region
);
errors.push(RegionResolutionError::SubSupConflict(
node_idx,
origin,
@ -674,6 +701,7 @@ impl<'cx, 'tcx> LexicalResolver<'cx, 'tcx> {
lower_bound.region,
upper_bound.origin.clone(),
upper_bound.region,
influences,
));
return;
}

36
compiler/rustc_middle/src/ty/context.rs
View File

@ -1481,40 +1481,8 @@ impl<'tcx> TyCtxt<'tcx> {
scope_def_id: LocalDefId,
) -> Vec<&'tcx hir::Ty<'tcx>> {
let hir_id = self.hir().local_def_id_to_hir_id(scope_def_id);
let hir_output = match self.hir().get(hir_id) {
Node::Item(hir::Item {
kind:
ItemKind::Fn(
hir::FnSig {
decl: hir::FnDecl { output: hir::FnRetTy::Return(ty), .. },
..
},
..,
),
..
})
| Node::ImplItem(hir::ImplItem {
kind:
hir::ImplItemKind::Fn(
hir::FnSig {
decl: hir::FnDecl { output: hir::FnRetTy::Return(ty), .. },
..
},
_,
),
..
})
| Node::TraitItem(hir::TraitItem {
kind:
hir::TraitItemKind::Fn(
hir::FnSig {
decl: hir::FnDecl { output: hir::FnRetTy::Return(ty), .. },
..
},
_,
),
..
}) => ty,
let hir_output = match self.hir().fn_decl_by_hir_id(hir_id) {
Some(hir::FnDecl { output: hir::FnRetTy::Return(ty), .. }) => ty,
_ => return vec![],
};

20
compiler/rustc_middle/src/ty/diagnostics.rs
View File

@ -6,6 +6,7 @@ use rustc_errors::{Applicability, DiagnosticBuilder};
use rustc_hir as hir;
use rustc_hir::def_id::DefId;
use rustc_hir::{QPath, TyKind, WhereBoundPredicate, WherePredicate};
use rustc_span::Span;
impl<'tcx> TyS<'tcx> {
/// Similar to `TyS::is_primitive`, but also considers inferred numeric values to be primitive.
@ -432,3 +433,22 @@ impl<'v> hir::intravisit::Visitor<'v> for TraitObjectVisitor<'v> {
hir::intravisit::walk_ty(self, ty);
}
}
/// Collect al types that have an implicit `'static` obligation that we could suggest `'_` for.
pub struct StaticLifetimeVisitor<'tcx>(pub Vec<Span>, pub crate::hir::map::Map<'tcx>);
impl<'v> hir::intravisit::Visitor<'v> for StaticLifetimeVisitor<'v> {
type Map = rustc_hir::intravisit::ErasedMap<'v>;
fn nested_visit_map(&mut self) -> hir::intravisit::NestedVisitorMap<Self::Map> {
hir::intravisit::NestedVisitorMap::None
}
fn visit_lifetime(&mut self, lt: &'v hir::Lifetime) {
if let hir::LifetimeName::ImplicitObjectLifetimeDefault | hir::LifetimeName::Static =
lt.name
{
self.0.push(lt.span);
}
}
}

2
src/test/ui/associated-types/cache/project-fn-ret-contravariant.transmute.stderr vendored
View File

@ -4,7 +4,7 @@ error[E0759]: `x` has lifetime `'a` but it needs to satisfy a `'static` lifetime
LL | fn baz<'a,'b>(x: &'a u32) -> &'static u32 {
| ------- this data with lifetime `'a`...
LL | bar(foo, x)
| ----^^^---- ...is captured and required to live as long as `'static` here
| ^^^ - ...is used and required to live as long as `'static` here
error: aborting due to previous error

11
src/test/ui/associated-types/cache/project-fn-ret-invariant.transmute.stderr vendored
View File

@ -5,7 +5,16 @@ LL | fn baz<'a, 'b>(x: Type<'a>) -> Type<'static> {
| -------- this data with lifetime `'a`...
...
LL | bar(foo, x)
| ----^^^---- ...is captured and required to live as long as `'static` here
| ^^^ - ...is used and required to live as long as `'static` here
|
note: `'static` lifetime requirement introduced by the return type
--> $DIR/project-fn-ret-invariant.rs:45:37
|
LL | fn baz<'a, 'b>(x: Type<'a>) -> Type<'static> {
| ^^^^^^^ `'static` requirement introduced here
...
LL | bar(foo, x)
| ----------- because of this returned expression
error: aborting due to previous error

13
src/test/ui/async-await/issues/issue-62097.stderr
View File

@ -2,12 +2,15 @@ error[E0759]: `self` has an anonymous lifetime `'_` but it needs to satisfy a `'
--> $DIR/issue-62097.rs:12:31
|
LL | pub async fn run_dummy_fn(&self) {
| ^^^^^
| |
| this data with an anonymous lifetime `'_`...
| ...is captured here...
| ^^^^^ this data with an anonymous lifetime `'_`...
LL | foo(|| self.bar()).await;
| --- ...and is required to live as long as `'static` here
| --- ...is used and required to live as long as `'static` here
|
note: `'static` lifetime requirement introduced by this bound
--> $DIR/issue-62097.rs:4:19
|
LL | F: FnOnce() + 'static
| ^^^^^^^
error: aborting due to previous error

21
src/test/ui/async-await/issues/issue-72312.nll.stderr Normal file
View File

@ -0,0 +1,21 @@
error[E0521]: borrowed data escapes outside of associated function
--> $DIR/issue-72312.rs:13:24
|
LL | pub async fn start(&self) {
| -----
| |
| `self` is a reference that is only valid in the associated function body
| let's call the lifetime of this reference `'1`
...
LL | require_static(async move {
| ________________________^
LL | | &self;
LL | | });
| | ^
| | |
| |_________`self` escapes the associated function body here
| argument requires that `'1` must outlive `'static`
error: aborting due to previous error
For more information about this error, try `rustc --explain E0521`.

19
src/test/ui/async-await/issues/issue-72312.rs Normal file
View File

@ -0,0 +1,19 @@
// edition:2018
fn require_static<T: 'static>(val: T) -> T {
//~^ NOTE 'static` lifetime requirement introduced by this bound
val
}
struct Problem;
impl Problem {
pub async fn start(&self) { //~ ERROR E0759
//~^ NOTE this data with an anonymous lifetime `'_`
//~| NOTE in this expansion of desugaring of `async` block or function
require_static(async move { //~ NOTE ...and is required to live as long as `'static` here
&self; //~ NOTE ...is used here...
});
}
}
fn main() {}

23
src/test/ui/async-await/issues/issue-72312.stderr Normal file
View File

@ -0,0 +1,23 @@
error[E0759]: `self` has an anonymous lifetime `'_` but it needs to satisfy a `'static` lifetime requirement
--> $DIR/issue-72312.rs:10:24
|
LL | pub async fn start(&self) {
| ^^^^^ this data with an anonymous lifetime `'_`...
...
LL | &self;
| ----- ...is used here...
|
note: ...and is required to live as long as `'static` here
--> $DIR/issue-72312.rs:13:9
|
LL | require_static(async move {
| ^^^^^^^^^^^^^^
note: `'static` lifetime requirement introduced by this bound
--> $DIR/issue-72312.rs:2:22
|
LL | fn require_static<T: 'static>(val: T) -> T {
| ^^^^^^^
error: aborting due to previous error
For more information about this error, try `rustc --explain E0759`.

7
src/test/ui/closures/closure-bounds-static-cant-capture-borrowed.stderr
View File

@ -8,13 +8,18 @@ LL | bar(|| {
LL | |
LL | | let _ = x;
LL | | })
| |_____^ ...is captured here...
| |_____^ ...is used here...
|
note: ...and is required to live as long as `'static` here
--> $DIR/closure-bounds-static-cant-capture-borrowed.rs:5:5
|
LL | bar(|| {
| ^^^
note: `'static` lifetime requirement introduced by this bound
--> $DIR/closure-bounds-static-cant-capture-borrowed.rs:1:39
|
LL | fn bar<F>(blk: F) where F: FnOnce() + 'static {
| ^^^^^^^
error: aborting due to previous error

2
src/test/ui/generator/generator-region-requirements.stderr
View File

@ -5,7 +5,7 @@ LL | fn dangle(x: &mut i32) -> &'static mut i32 {
| -------- this data with an anonymous lifetime `'_`...
...
LL | x
| ^ ...is captured here...
| ^ ...is used here...
...
LL | GeneratorState::Complete(c) => return c,
| - ...and is required to live as long as `'static` here

12
src/test/ui/generic-associated-types/projection-type-lifetime-mismatch.stderr
View File

@ -4,7 +4,9 @@ error[E0759]: `x` has an anonymous lifetime `'_` but it needs to satisfy a `'sta
LL | fn f(x: &impl for<'a> X<Y<'a> = &'a ()>) -> &'static () {
| ------------------------------- this data with an anonymous lifetime `'_`...
LL | x.m()
| --^-- ...is captured and required to live as long as `'static` here
| - ^
| |
| ...is used and required to live as long as `'static` here
error[E0759]: `x` has an anonymous lifetime `'_` but it needs to satisfy a `'static` lifetime requirement
--> $DIR/projection-type-lifetime-mismatch.rs:22:7
@ -12,7 +14,9 @@ error[E0759]: `x` has an anonymous lifetime `'_` but it needs to satisfy a `'sta
LL | fn g<T: for<'a> X<Y<'a> = &'a ()>>(x: &T) -> &'static () {
| -- this data with an anonymous lifetime `'_`...
LL | x.m()
| --^-- ...is captured and required to live as long as `'static` here
| - ^
| |
| ...is used and required to live as long as `'static` here
error[E0759]: `x` has an anonymous lifetime `'_` but it needs to satisfy a `'static` lifetime requirement
--> $DIR/projection-type-lifetime-mismatch.rs:27:7
@ -20,7 +24,9 @@ error[E0759]: `x` has an anonymous lifetime `'_` but it needs to satisfy a `'sta
LL | fn h(x: &()) -> &'static () {
| --- this data with an anonymous lifetime `'_`...
LL | x.m()
| --^-- ...is captured and required to live as long as `'static` here
| - ^
| |
| ...is used and required to live as long as `'static` here
error: aborting due to 3 previous errors

2
src/test/ui/impl-header-lifetime-elision/dyn-trait.stderr
View File

@ -4,7 +4,7 @@ error[E0759]: `x` has lifetime `'a` but it needs to satisfy a `'static` lifetime
LL | fn with_dyn_debug_static<'a>(x: Box<dyn Debug + 'a>) {
| ------------------- this data with lifetime `'a`...
LL | static_val(x);
| ^ ...is captured here...
| ^ ...is used here...
|
note: ...and is required to live as long as `'static` here
--> $DIR/dyn-trait.rs:20:5

44
src/test/ui/impl-trait/must_outlive_least_region_or_bound.stderr
View File

@ -28,7 +28,7 @@ error[E0759]: `x` has an anonymous lifetime `'_` but it needs to satisfy a `'sta
--> $DIR/must_outlive_least_region_or_bound.rs:9:46
|
LL | fn elided2(x: &i32) -> impl Copy + 'static { x }
| ---- ^ ...is captured here...
| ---- ^ ...is used here...
| |
| this data with an anonymous lifetime `'_`...
|
@ -50,7 +50,7 @@ error[E0759]: `x` has lifetime `'a` but it needs to satisfy a `'static` lifetime
--> $DIR/must_outlive_least_region_or_bound.rs:11:55
|
LL | fn explicit2<'a>(x: &'a i32) -> impl Copy + 'static { x }
| ------- ^ ...is captured here...
| ------- ^ ...is used here...
| |
| this data with lifetime `'a`...
|
@ -80,7 +80,7 @@ error[E0759]: `x` has an anonymous lifetime `'_` but it needs to satisfy a `'sta
--> $DIR/must_outlive_least_region_or_bound.rs:24:65
|
LL | fn elided5(x: &i32) -> (Box<dyn Debug>, impl Debug) { (Box::new(x), x) }
| ---- this data with an anonymous lifetime `'_`... ^ ...is captured here, requiring it to live as long as `'static`
| ---- this data with an anonymous lifetime `'_`... ^ ...is used and required to live as long as `'static` here
|
help: to declare that the trait object captures data from argument `x`, you can add an explicit `'_` lifetime bound
|
@ -95,7 +95,7 @@ error[E0759]: `x` has lifetime `'a` but it needs to satisfy a `'static` lifetime
--> $DIR/must_outlive_least_region_or_bound.rs:29:69
|
LL | fn with_bound<'a>(x: &'a i32) -> impl LifetimeTrait<'a> + 'static { x }
| ------- this data with lifetime `'a`... ^ ...is captured here...
| ------- this data with lifetime `'a`... ^ ...is used here...
|
note: ...and is required to live as long as `'static` here
--> $DIR/must_outlive_least_region_or_bound.rs:29:34
@ -136,10 +136,17 @@ error[E0759]: `x` has an anonymous lifetime `'_` but it needs to satisfy a `'sta
--> $DIR/must_outlive_least_region_or_bound.rs:16:50
|
LL | fn elided3(x: &i32) -> Box<dyn Debug> { Box::new(x) }
| ---- ^ ...is captured here, requiring it to live as long as `'static`
| ---- ^ ...is used and required to live as long as `'static` here
| |
| this data with an anonymous lifetime `'_`...
|
note: `'static` lifetime requirement introduced by the return type
--> $DIR/must_outlive_least_region_or_bound.rs:16:28
|
LL | fn elided3(x: &i32) -> Box<dyn Debug> { Box::new(x) }
| ^^^^^^^^^ ----------- because of this returned expression
| |
| `'static` requirement introduced here
help: to declare that the trait object captures data from argument `x`, you can add an explicit `'_` lifetime bound
|
LL | fn elided3(x: &i32) -> Box<dyn Debug + '_> { Box::new(x) }
@ -149,10 +156,17 @@ error[E0759]: `x` has lifetime `'a` but it needs to satisfy a `'static` lifetime
--> $DIR/must_outlive_least_region_or_bound.rs:18:59
|
LL | fn explicit3<'a>(x: &'a i32) -> Box<dyn Debug> { Box::new(x) }
| ------- ^ ...is captured here, requiring it to live as long as `'static`
| ------- ^ ...is used and required to live as long as `'static` here
| |
| this data with lifetime `'a`...
|
note: `'static` lifetime requirement introduced by the return type
--> $DIR/must_outlive_least_region_or_bound.rs:18:37
|
LL | fn explicit3<'a>(x: &'a i32) -> Box<dyn Debug> { Box::new(x) }
| ^^^^^^^^^ ----------- because of this returned expression
| |
| `'static` requirement introduced here
help: to declare that the trait object captures data from argument `x`, you can add an explicit `'a` lifetime bound
|
LL | fn explicit3<'a>(x: &'a i32) -> Box<dyn Debug + 'a> { Box::new(x) }
@ -162,10 +176,17 @@ error[E0759]: `x` has an anonymous lifetime `'_` but it needs to satisfy a `'sta
--> $DIR/must_outlive_least_region_or_bound.rs:20:60
|
LL | fn elided4(x: &i32) -> Box<dyn Debug + 'static> { Box::new(x) }
| ---- ^ ...is captured here, requiring it to live as long as `'static`
| ---- ^ ...is used and required to live as long as `'static` here
| |
| this data with an anonymous lifetime `'_`...
|
note: `'static` lifetime requirement introduced by the return type
--> $DIR/must_outlive_least_region_or_bound.rs:20:40
|
LL | fn elided4(x: &i32) -> Box<dyn Debug + 'static> { Box::new(x) }
| ^^^^^^^ ----------- because of this returned expression
| |
| `'static` requirement introduced here
help: consider changing the trait object's explicit `'static` bound to the lifetime of argument `x`
|
LL | fn elided4(x: &i32) -> Box<dyn Debug + '_> { Box::new(x) }
@ -179,8 +200,15 @@ error[E0759]: `x` has lifetime `'a` but it needs to satisfy a `'static` lifetime
--> $DIR/must_outlive_least_region_or_bound.rs:22:69
|
LL | fn explicit4<'a>(x: &'a i32) -> Box<dyn Debug + 'static> { Box::new(x) }
| ------- this data with lifetime `'a`... ^ ...is captured here, requiring it to live as long as `'static`
| ------- this data with lifetime `'a`... ^ ...is used and required to live as long as `'static` here
|
note: `'static` lifetime requirement introduced by the return type
--> $DIR/must_outlive_least_region_or_bound.rs:22:49
|
LL | fn explicit4<'a>(x: &'a i32) -> Box<dyn Debug + 'static> { Box::new(x) }
| ^^^^^^^ ----------- because of this returned expression
| |
| `'static` requirement introduced here
help: consider changing the trait object's explicit `'static` bound to the lifetime of argument `x`
|
LL | fn explicit4<'a>(x: &'a i32) -> Box<dyn Debug + 'a> { Box::new(x) }

2
src/test/ui/issues/issue-16922.stderr
View File

@ -4,7 +4,7 @@ error[E0759]: `value` has an anonymous lifetime `'_` but it needs to satisfy a `
LL | fn foo<T: Any>(value: &T) -> Box<dyn Any> {
| -- this data with an anonymous lifetime `'_`...
LL | Box::new(value) as Box<dyn Any>
| ^^^^^ ...is captured here, requiring it to live as long as `'static`
| ^^^^^ ...is used and required to live as long as `'static` here
|
help: to declare that the trait object captures data from argument `value`, you can add an explicit `'_` lifetime bound
|

2
src/test/ui/issues/issue-46983.stderr
View File

@ -4,7 +4,7 @@ error[E0759]: `x` has an anonymous lifetime `'_` but it needs to satisfy a `'sta
LL | fn foo(x: &u32) -> &'static u32 {
| ---- this data with an anonymous lifetime `'_`...
LL | &*x
| ^^^ ...is captured and required to live as long as `'static` here
| ^^^ ...is used and required to live as long as `'static` here
error: aborting due to previous error

2
src/test/ui/lifetimes/issue-90600-expected-return-static-indirect.stderr
View File

@ -4,7 +4,7 @@ error[E0759]: `foo` has an anonymous lifetime `'_` but it needs to satisfy a `'s
LL | fn inner(mut foo: &[u8]) {
| ----- this data with an anonymous lifetime `'_`...
LL | let refcell = RefCell::new(&mut foo);
| ^^^^^^^^ ...is captured here...
| ^^^^^^^^ ...is used here...
...
LL | read_thing(read);
| ---- ...and is required to live as long as `'static` here

2
src/test/ui/nll/user-annotations/constant-in-expr-inherent-1.stderr
View File

@ -4,7 +4,7 @@ error[E0759]: `fn` parameter has lifetime `'a` but it needs to satisfy a `'stati
LL | fn foo<'a>(_: &'a u32) -> &'static u32 {
| ------- this data with lifetime `'a`...
LL | <Foo<'a>>::C
| ^^^^^^^^^^^^ ...is captured and required to live as long as `'static` here
| ^^^^^^^^^^^^ ...is used and required to live as long as `'static` here
error: aborting due to previous error

10
src/test/ui/object-lifetime/object-lifetime-default-from-box-error.stderr
View File

@ -5,8 +5,16 @@ LL | fn load(ss: &mut SomeStruct) -> Box<dyn SomeTrait> {
| --------------- this data with an anonymous lifetime `'_`...
...
LL | ss.r
| ^^^^ ...is captured and required to live as long as `'static` here
| ^^^^ ...is used and required to live as long as `'static` here
|
note: `'static` lifetime requirement introduced by the return type
--> $DIR/object-lifetime-default-from-box-error.rs:14:37
|
LL | fn load(ss: &mut SomeStruct) -> Box<dyn SomeTrait> {
| ^^^^^^^^^^^^^ `'static` requirement introduced here
...
LL | ss.r
| ---- because of this returned expression
help: to declare that the trait object captures data from argument `ss`, you can add an explicit `'_` lifetime bound
|
LL | fn load(ss: &mut SomeStruct) -> Box<dyn SomeTrait + '_> {

21
src/test/ui/regions/region-object-lifetime-in-coercion.stderr
View File

@ -4,7 +4,7 @@ error[E0759]: `v` has an anonymous lifetime `'_` but it needs to satisfy a `'sta
LL | fn a(v: &[u8]) -> Box<dyn Foo + 'static> {
| ----- this data with an anonymous lifetime `'_`...
LL | let x: Box<dyn Foo + 'static> = Box::new(v);
| ^ ...is captured here, requiring it to live as long as `'static`
| ^ ...is used and required to live as long as `'static` here
|
help: consider changing the trait object's explicit `'static` bound to the lifetime of argument `v`
|
@ -21,8 +21,15 @@ error[E0759]: `v` has an anonymous lifetime `'_` but it needs to satisfy a `'sta
LL | fn b(v: &[u8]) -> Box<dyn Foo + 'static> {
| ----- this data with an anonymous lifetime `'_`...
LL | Box::new(v)
| ^ ...is captured here, requiring it to live as long as `'static`
| ^ ...is used and required to live as long as `'static` here
|
note: `'static` lifetime requirement introduced by the return type
--> $DIR/region-object-lifetime-in-coercion.rs:12:33
|
LL | fn b(v: &[u8]) -> Box<dyn Foo + 'static> {
| ^^^^^^^ `'static` requirement introduced here
LL | Box::new(v)
| ----------- because of this returned expression
help: consider changing the trait object's explicit `'static` bound to the lifetime of argument `v`
|
LL | fn b(v: &[u8]) -> Box<dyn Foo + '_> {
@ -39,8 +46,16 @@ LL | fn c(v: &[u8]) -> Box<dyn Foo> {
| ----- this data with an anonymous lifetime `'_`...
...
LL | Box::new(v)
| ^ ...is captured here, requiring it to live as long as `'static`
| ^ ...is used and required to live as long as `'static` here
|
note: `'static` lifetime requirement introduced by the return type
--> $DIR/region-object-lifetime-in-coercion.rs:16:23
|
LL | fn c(v: &[u8]) -> Box<dyn Foo> {
| ^^^^^^^ `'static` requirement introduced here
...
LL | Box::new(v)
| ----------- because of this returned expression
help: to declare that the trait object captures data from argument `v`, you can add an explicit `'_` lifetime bound
|
LL | fn c(v: &[u8]) -> Box<dyn Foo + '_> {

2
src/test/ui/regions/regions-addr-of-self.stderr
View File

@ -4,7 +4,7 @@ error[E0759]: `self` has an anonymous lifetime `'_` but it needs to satisfy a `'
LL | pub fn chase_cat(&mut self) {
| --------- this data with an anonymous lifetime `'_`...
LL | let p: &'static mut usize = &mut self.cats_chased;
| ^^^^^^^^^^^^^^^^^^^^^ ...is captured and required to live as long as `'static` here
| ^^^^^^^^^^^^^^^^^^^^^ ...is used and required to live as long as `'static` here
error: aborting due to previous error

9
src/test/ui/regions/regions-close-object-into-object-2.stderr
View File

@ -4,8 +4,15 @@ error[E0759]: `v` has lifetime `'a` but it needs to satisfy a `'static` lifetime
LL | fn g<'a, T: 'static>(v: Box<dyn A<T> + 'a>) -> Box<dyn X + 'static> {
| ------------------ this data with lifetime `'a`...
LL | Box::new(B(&*v)) as Box<dyn X>
| ^^^ ...is captured here, requiring it to live as long as `'static`
| ^^^ ...is used and required to live as long as `'static` here
|
note: `'static` lifetime requirement introduced by the return type
--> $DIR/regions-close-object-into-object-2.rs:8:60
|
LL | fn g<'a, T: 'static>(v: Box<dyn A<T> + 'a>) -> Box<dyn X + 'static> {
| ^^^^^^^ `'static` requirement introduced here
LL | Box::new(B(&*v)) as Box<dyn X>
| ------------------------------ because of this returned expression
help: consider changing the trait object's explicit `'static` bound to the lifetime of argument `v`
|
LL | fn g<'a, T: 'static>(v: Box<dyn A<T> + 'a>) -> Box<dyn X + 'a> {

9
src/test/ui/regions/regions-close-object-into-object-4.stderr
View File

@ -4,8 +4,15 @@ error[E0759]: `v` has lifetime `'a` but it needs to satisfy a `'static` lifetime
LL | fn i<'a, T, U>(v: Box<dyn A<U>+'a>) -> Box<dyn X + 'static> {
| ---------------- this data with lifetime `'a`...
LL | Box::new(B(&*v)) as Box<dyn X>
| ^^^ ...is captured here, requiring it to live as long as `'static`
| ^^^ ...is used and required to live as long as `'static` here
|
note: `'static` lifetime requirement introduced by the return type
--> $DIR/regions-close-object-into-object-4.rs:8:52
|
LL | fn i<'a, T, U>(v: Box<dyn A<U>+'a>) -> Box<dyn X + 'static> {
| ^^^^^^^ `'static` requirement introduced here
LL | Box::new(B(&*v)) as Box<dyn X>
| ------------------------------ because of this returned expression
help: consider changing the trait object's explicit `'static` bound to the lifetime of argument `v`
|
LL | fn i<'a, T, U>(v: Box<dyn A<U>+'a>) -> Box<dyn X + 'a> {

10
src/test/ui/regions/regions-proc-bound-capture.stderr
View File

@ -5,8 +5,16 @@ LL | fn static_proc(x: &isize) -> Box<dyn FnMut() -> (isize) + 'static> {
| ------ this data with an anonymous lifetime `'_`...
LL | // This is illegal, because the region bound on `proc` is 'static.
LL | Box::new(move || { *x })
| ^^^^^^^^^^^^^^ ...is captured here, requiring it to live as long as `'static`
| ^^^^^^^^^^^^^^ ...is used and required to live as long as `'static` here
|
note: `'static` lifetime requirement introduced by the return type
--> $DIR/regions-proc-bound-capture.rs:7:59
|
LL | fn static_proc(x: &isize) -> Box<dyn FnMut() -> (isize) + 'static> {
| ^^^^^^^ `'static` requirement introduced here
LL | // This is illegal, because the region bound on `proc` is 'static.
LL | Box::new(move || { *x })
| ------------------------ because of this returned expression
help: consider changing the trait object's explicit `'static` bound to the lifetime of argument `x`
|
LL | fn static_proc(x: &isize) -> Box<dyn FnMut() -> (isize) + '_> {

4
src/test/ui/regions/regions-static-bound.stderr
View File

@ -17,7 +17,7 @@ error[E0759]: `u` has an anonymous lifetime `'_` but it needs to satisfy a `'sta
LL | fn error(u: &(), v: &()) {
| --- this data with an anonymous lifetime `'_`...
LL | static_id(&u);
| ^^^^^^^^^ -- ...is captured here...
| ^^^^^^^^^ -- ...is used here...
|
note: ...and is required to live as long as `'static` here
--> $DIR/regions-static-bound.rs:10:5
@ -32,7 +32,7 @@ LL | fn error(u: &(), v: &()) {
| --- this data with an anonymous lifetime `'_`...
LL | static_id(&u);
LL | static_id_indirect(&v);
| ^^^^^^^^^^^^^^^^^^ -- ...is captured here...
| ^^^^^^^^^^^^^^^^^^ -- ...is used here...
|
note: ...and is required to live as long as `'static` here
--> $DIR/regions-static-bound.rs:11:5

2
src/test/ui/suggestions/impl-on-dyn-trait-with-implicit-static-bound-needing-more-suggestions.stderr
View File

@ -22,7 +22,7 @@ error[E0772]: `val` has lifetime `'a` but calling `use_self` introduces an impli
LL | fn use_it<'a>(val: Box<dyn ObjectTrait<Assoc = i32> + 'a>) -> &'a () {
| -------------------------------------- this data with lifetime `'a`...
LL | val.use_self()
| ^^^^^^^^ ...is captured and required to live as long as `'static` here
| ^^^^^^^^ ...is used and required to live as long as `'static` here
|
note: the used `impl` has a `'static` requirement
--> $DIR/impl-on-dyn-trait-with-implicit-static-bound-needing-more-suggestions.rs:60:30

12
src/test/ui/suggestions/impl-on-dyn-trait-with-implicit-static-bound.stderr
View File

@ -4,7 +4,7 @@ error[E0759]: `val` has lifetime `'a` but it needs to satisfy a `'static` lifeti
LL | fn use_it<'a, T>(val: &'a dyn ObjectTrait<T>) -> impl OtherTrait<'a> + 'a {
| ---------------------- this data with lifetime `'a`...
LL | val.use_self::<T>()
| ^^^^^^^^ ...is captured and required to live as long as `'static` here
| ^^^^^^^^ ...is used and required to live as long as `'static` here
|
note: the used `impl` has a `'static` requirement
--> $DIR/impl-on-dyn-trait-with-implicit-static-bound.rs:14:32
@ -24,7 +24,7 @@ error[E0772]: `val` has lifetime `'a` but calling `use_self` introduces an impli
LL | fn use_it<'a>(val: &'a dyn ObjectTrait) -> impl OtherTrait<'a> + 'a {
| ------------------- this data with lifetime `'a`...
LL | val.use_self()
| ^^^^^^^^ ...is captured and required to live as long as `'static` here because of an implicit lifetime bound on the inherent `impl`
| ^^^^^^^^ ...is used and required to live as long as `'static` here because of an implicit lifetime bound on the inherent `impl`
|
note: the used `impl` has a `'static` requirement
--> $DIR/impl-on-dyn-trait-with-implicit-static-bound.rs:64:14
@ -44,7 +44,7 @@ error[E0759]: `val` has lifetime `'a` but it needs to satisfy a `'static` lifeti
LL | fn use_it<'a>(val: &'a dyn ObjectTrait) -> impl OtherTrait<'a> {
| ------------------- this data with lifetime `'a`...
LL | val.use_self()
| ^^^^^^^^ ...is captured and required to live as long as `'static` here
| ^^^^^^^^ ...is used and required to live as long as `'static` here
|
note: the used `impl` has a `'static` requirement
--> $DIR/impl-on-dyn-trait-with-implicit-static-bound.rs:85:26
@ -69,7 +69,7 @@ error[E0759]: `val` has lifetime `'a` but it needs to satisfy a `'static` lifeti
LL | fn use_it<'a>(val: &'a dyn ObjectTrait) -> impl OtherTrait<'a> + 'a {
| ------------------- this data with lifetime `'a`...
LL | MyTrait::use_self(val)
| ^^^ ...is captured here...
| ^^^ ...is used here...
|
note: ...and is required to live as long as `'static` here
--> $DIR/impl-on-dyn-trait-with-implicit-static-bound.rs:108:9
@ -95,7 +95,7 @@ error[E0772]: `val` has lifetime `'a` but calling `use_self` introduces an impli
LL | fn use_it<'a>(val: &'a dyn ObjectTrait) -> &'a () {
| ------------------- this data with lifetime `'a`...
LL | val.use_self()
| ^^^^^^^^ ...is captured and required to live as long as `'static` here
| ^^^^^^^^ ...is used and required to live as long as `'static` here
|
note: the used `impl` has a `'static` requirement
--> $DIR/impl-on-dyn-trait-with-implicit-static-bound.rs:31:26
@ -115,7 +115,7 @@ error[E0772]: `val` has lifetime `'a` but calling `use_self` introduces an impli
LL | fn use_it<'a>(val: &'a Box<dyn ObjectTrait + 'a>) -> &'a () {
| ----------------------------- this data with lifetime `'a`...
LL | val.use_self()
| ^^^^^^^^ ...is captured and required to live as long as `'static` here
| ^^^^^^^^ ...is used and required to live as long as `'static` here
|
note: the used `impl` has a `'static` requirement
--> $DIR/impl-on-dyn-trait-with-implicit-static-bound.rs:48:30

8
src/test/ui/suggestions/lifetimes/trait-object-nested-in-impl-trait.stderr
View File

@ -7,7 +7,7 @@ LL | fn iter(&self) -> impl Iterator<Item = Box<dyn Foo>> {
LL | remaining: self.0.iter(),
| ------ ^^^^
| |
| ...is captured here...
| ...is used here...
|
note: ...and is required to live as long as `'static` here
--> $DIR/trait-object-nested-in-impl-trait.rs:27:23
@ -32,7 +32,7 @@ LL | fn iter(&self) -> impl Iterator<Item = Box<dyn Foo>> + '_ {
LL | remaining: self.0.iter(),
| ------ ^^^^
| |
| ...is captured here...
| ...is used here...
|
note: ...and is required to live as long as `'static` here
--> $DIR/trait-object-nested-in-impl-trait.rs:38:23
@ -53,7 +53,7 @@ LL | fn iter<'a>(&'a self) -> impl Iterator<Item = Box<dyn Foo>> + 'a {
LL | remaining: self.0.iter(),
| ------ ^^^^
| |
| ...is captured here...
| ...is used here...
|
note: ...and is required to live as long as `'static` here
--> $DIR/trait-object-nested-in-impl-trait.rs:49:30
@ -74,7 +74,7 @@ LL | fn iter<'a>(&'a self) -> impl Iterator<Item = Box<dyn Foo>> {
LL | remaining: self.0.iter(),
| ------ ^^^^
| |
| ...is captured here...
| ...is used here...
|
note: ...and is required to live as long as `'static` here
--> $DIR/trait-object-nested-in-impl-trait.rs:60:30

18
src/test/ui/traits/trait-upcasting/type-checking-test-4.rs
View File

@ -29,4 +29,22 @@ fn test_wrong3<'a>(x: &dyn Foo<'a>) -> Option<&'static u32> {
y.get_b() // ERROR
}
fn test_wrong4<'a>(x: &dyn Foo<'a>) -> Option<&'static u32> {
<_ as Bar>::get_b(x) // ERROR
//~^ ERROR `x` has lifetime `'a` but it needs to satisfy a `'static` lifetime requirement
}
fn test_wrong5<'a>(x: &dyn Foo<'a>) -> Option<&'static u32> {
<_ as Bar<'_, '_>>::get_b(x) // ERROR
//~^ ERROR `x` has lifetime `'a` but it needs to satisfy a `'static` lifetime requirement
}
fn test_wrong6<'a>(x: &dyn Foo<'a>) -> Option<&'static u32> {
let y = x as &dyn Bar<'_, '_>;
//~^ ERROR `x` has lifetime `'a` but it needs to satisfy a `'static` lifetime requirement
y.get_b(); // ERROR
let z = y;
z.get_b() // ERROR
}
fn main() {}

82
src/test/ui/traits/trait-upcasting/type-checking-test-4.stderr
View File

@ -36,12 +36,88 @@ LL | fn test_wrong3<'a>(x: &dyn Foo<'a>) -> Option<&'static u32> {
LL | let y = x as &dyn Bar<'_, '_>;
| - ^^
| |
| ...is captured here...
| ...is used here...
LL |
LL | y.get_b() // ERROR
| --------- ...and is required to live as long as `'static` here
| - ...is used here...
|
note: ...and is required to live as long as `'static` here
--> $DIR/type-checking-test-4.rs:29:5
|
LL | y.get_b() // ERROR
| ^^^^^^^^^
note: `'static` lifetime requirement introduced by the return type
--> $DIR/type-checking-test-4.rs:26:48
|
LL | fn test_wrong3<'a>(x: &dyn Foo<'a>) -> Option<&'static u32> {
| ^^^^^^^ `'static` requirement introduced here
...
LL | y.get_b() // ERROR
| --------- because of this returned expression
error: aborting due to 3 previous errors
error[E0759]: `x` has lifetime `'a` but it needs to satisfy a `'static` lifetime requirement
--> $DIR/type-checking-test-4.rs:33:5
|
LL | fn test_wrong4<'a>(x: &dyn Foo<'a>) -> Option<&'static u32> {
| ------------ this data with lifetime `'a`...
LL | <_ as Bar>::get_b(x) // ERROR
| ^^^^^^^^^^^^^^^^^ ...is used and required to live as long as `'static` here
|
note: `'static` lifetime requirement introduced by the return type
--> $DIR/type-checking-test-4.rs:32:48
|
LL | fn test_wrong4<'a>(x: &dyn Foo<'a>) -> Option<&'static u32> {
| ^^^^^^^ `'static` requirement introduced here
LL | <_ as Bar>::get_b(x) // ERROR
| -------------------- because of this returned expression
error[E0759]: `x` has lifetime `'a` but it needs to satisfy a `'static` lifetime requirement
--> $DIR/type-checking-test-4.rs:38:15
|
LL | fn test_wrong5<'a>(x: &dyn Foo<'a>) -> Option<&'static u32> {
| ------------ this data with lifetime `'a`...
LL | <_ as Bar<'_, '_>>::get_b(x) // ERROR
| ----------^^------------- ...is used and required to live as long as `'static` here
|
note: `'static` lifetime requirement introduced by the return type
--> $DIR/type-checking-test-4.rs:37:48
|
LL | fn test_wrong5<'a>(x: &dyn Foo<'a>) -> Option<&'static u32> {
| ^^^^^^^ `'static` requirement introduced here
LL | <_ as Bar<'_, '_>>::get_b(x) // ERROR
| ---------------------------- because of this returned expression
error[E0759]: `x` has lifetime `'a` but it needs to satisfy a `'static` lifetime requirement
--> $DIR/type-checking-test-4.rs:43:27
|
LL | fn test_wrong6<'a>(x: &dyn Foo<'a>) -> Option<&'static u32> {
| ------------ this data with lifetime `'a`...
LL | let y = x as &dyn Bar<'_, '_>;
| - ^^
| |
| ...is used here...
LL |
LL | y.get_b(); // ERROR
| - ...is used here...
LL | let z = y;
LL | z.get_b() // ERROR
| - ...is used here...
|
note: ...and is required to live as long as `'static` here
--> $DIR/type-checking-test-4.rs:47:5
|
LL | z.get_b() // ERROR
| ^^^^^^^^^
note: `'static` lifetime requirement introduced by the return type
--> $DIR/type-checking-test-4.rs:42:48
|
LL | fn test_wrong6<'a>(x: &dyn Foo<'a>) -> Option<&'static u32> {
| ^^^^^^^ `'static` requirement introduced here
...
LL | z.get_b() // ERROR
| --------- because of this returned expression
error: aborting due to 6 previous errors
Some errors have detailed explanations: E0308, E0759.
For more information about an error, try `rustc --explain E0308`.

12
src/test/ui/underscore-lifetime/dyn-trait-underscore.stderr
View File

@ -5,8 +5,18 @@ LL | fn a<T>(items: &[T]) -> Box<dyn Iterator<Item=&T>> {
| ---- this data with an anonymous lifetime `'_`...
LL | // ^^^^^^^^^^^^^^^^^^^^^ bound *here* defaults to `'static`
LL | Box::new(items.iter())
| ---------------^^^^--- ...is captured and required to live as long as `'static` here
| ----- ^^^^
| |
| ...is used and required to live as long as `'static` here
|
note: `'static` lifetime requirement introduced by the return type
--> $DIR/dyn-trait-underscore.rs:6:29
|
LL | fn a<T>(items: &[T]) -> Box<dyn Iterator<Item=&T>> {
| ^^^^^^^^^^^^^^^^^^^^^ `'static` requirement introduced here
LL | // ^^^^^^^^^^^^^^^^^^^^^ bound *here* defaults to `'static`
LL | Box::new(items.iter())
| ---------------------- because of this returned expression
help: to declare that the trait object captures data from argument `items`, you can add an explicit `'_` lifetime bound
|
LL | fn a<T>(items: &[T]) -> Box<dyn Iterator<Item=&T> + '_> {