Auto merge of #17941 - ChayimFriedman2:pre-closure-to-fn, r=Veykril

Preliminary work for #17940

I split the PR as requested, and made small commits.
This commit is contained in:
bors 2024-08-26 08:09:15 +00:00
commit 239dc5db1c
26 changed files with 816 additions and 167 deletions

View File

@ -74,6 +74,13 @@ pub fn as_enum_variant(self) -> Option<EnumVariantId> {
_ => None,
}
}
pub fn as_type_alias(self) -> Option<TypeAliasId> {
match self {
LangItemTarget::TypeAlias(id) => Some(id),
_ => None,
}
}
}
#[derive(Default, Debug, Clone, PartialEq, Eq)]
@ -117,11 +124,19 @@ pub(crate) fn crate_lang_items_query(
match def {
ModuleDefId::TraitId(trait_) => {
lang_items.collect_lang_item(db, trait_, LangItemTarget::Trait);
db.trait_data(trait_).items.iter().for_each(|&(_, assoc_id)| {
if let AssocItemId::FunctionId(f) = assoc_id {
db.trait_data(trait_).items.iter().for_each(
|&(_, assoc_id)| match assoc_id {
AssocItemId::FunctionId(f) => {
lang_items.collect_lang_item(db, f, LangItemTarget::Function);
}
});
AssocItemId::TypeAliasId(alias) => lang_items.collect_lang_item(
db,
alias,
LangItemTarget::TypeAlias,
),
AssocItemId::ConstId(_) => {}
},
);
}
ModuleDefId::AdtId(AdtId::EnumId(e)) => {
lang_items.collect_lang_item(db, e, LangItemTarget::EnumId);
@ -453,6 +468,7 @@ pub fn ty_rel_path(
Context, sym::Context, context, Target::Struct, GenericRequirement::None;
FuturePoll, sym::poll, future_poll_fn, Target::Method(MethodKind::Trait { body: false }), GenericRequirement::None;
FutureOutput, sym::future_output, future_output, Target::TypeAlias, GenericRequirement::None;
Option, sym::Option, option_type, Target::Enum, GenericRequirement::None;
OptionSome, sym::Some, option_some_variant, Target::Variant, GenericRequirement::None;
@ -467,6 +483,7 @@ pub fn ty_rel_path(
IntoFutureIntoFuture, sym::into_future, into_future_fn, Target::Method(MethodKind::Trait { body: false }), GenericRequirement::None;
IntoIterIntoIter, sym::into_iter, into_iter_fn, Target::Method(MethodKind::Trait { body: false }), GenericRequirement::None;
IteratorNext, sym::next, next_fn, Target::Method(MethodKind::Trait { body: false}), GenericRequirement::None;
Iterator, sym::iterator, iterator, Target::Trait, GenericRequirement::None;
PinNewUnchecked, sym::new_unchecked, new_unchecked_fn, Target::Method(MethodKind::Inherent), GenericRequirement::None;

View File

@ -59,6 +59,7 @@
generics::Generics,
infer::{coerce::CoerceMany, unify::InferenceTable},
lower::ImplTraitLoweringMode,
mir::MirSpan,
to_assoc_type_id,
traits::FnTrait,
utils::{InTypeConstIdMetadata, UnevaluatedConstEvaluatorFolder},
@ -553,6 +554,12 @@ pub(crate) struct InferenceContext<'a> {
// fields related to closure capture
current_captures: Vec<CapturedItemWithoutTy>,
/// A stack that has an entry for each projection in the current capture.
///
/// For example, in `a.b.c`, we capture the spans of `a`, `a.b`, and `a.b.c`.
/// We do that because sometimes we truncate projections (when a closure captures
/// both `a.b` and `a.b.c`), and we want to provide accurate spans in this case.
current_capture_span_stack: Vec<MirSpan>,
current_closure: Option<ClosureId>,
/// Stores the list of closure ids that need to be analyzed before this closure. See the
/// comment on `InferenceContext::sort_closures`
@ -634,6 +641,7 @@ fn new(
breakables: Vec::new(),
deferred_cast_checks: Vec::new(),
current_captures: Vec::new(),
current_capture_span_stack: Vec::new(),
current_closure: None,
deferred_closures: FxHashMap::default(),
closure_dependencies: FxHashMap::default(),

View File

@ -18,7 +18,7 @@
use hir_expand::name::Name;
use intern::sym;
use rustc_hash::FxHashMap;
use smallvec::SmallVec;
use smallvec::{smallvec, SmallVec};
use stdx::never;
use crate::{
@ -236,7 +236,13 @@ pub enum CaptureKind {
pub struct CapturedItem {
pub(crate) place: HirPlace,
pub(crate) kind: CaptureKind,
pub(crate) span: MirSpan,
/// The inner vec is the stacks; the outer vec is for each capture reference.
///
/// Even though we always report only the last span (i.e. the most inclusive span),
/// we need to keep them all, since when a closure occurs inside a closure, we
/// copy all captures of the inner closure to the outer closure, and then we may
/// truncate them, and we want the correct span to be reported.
span_stacks: SmallVec<[SmallVec<[MirSpan; 3]>; 3]>,
pub(crate) ty: Binders<Ty>,
}
@ -253,6 +259,10 @@ pub fn kind(&self) -> CaptureKind {
self.kind
}
pub fn spans(&self) -> SmallVec<[MirSpan; 3]> {
self.span_stacks.iter().map(|stack| *stack.last().expect("empty span stack")).collect()
}
pub fn display_place(&self, owner: DefWithBodyId, db: &dyn HirDatabase) -> String {
let body = db.body(owner);
let krate = owner.krate(db.upcast());
@ -314,7 +324,8 @@ pub fn display_place(&self, owner: DefWithBodyId, db: &dyn HirDatabase) -> Strin
pub(crate) struct CapturedItemWithoutTy {
pub(crate) place: HirPlace,
pub(crate) kind: CaptureKind,
pub(crate) span: MirSpan,
/// The inner vec is the stacks; the outer vec is for each capture reference.
pub(crate) span_stacks: SmallVec<[SmallVec<[MirSpan; 3]>; 3]>,
}
impl CapturedItemWithoutTy {
@ -333,7 +344,7 @@ fn with_ty(self, ctx: &mut InferenceContext<'_>) -> CapturedItem {
return CapturedItem {
place: self.place,
kind: self.kind,
span: self.span,
span_stacks: self.span_stacks,
ty: replace_placeholder_with_binder(ctx, ty),
};
@ -393,22 +404,26 @@ fn place_of_expr(&mut self, tgt_expr: ExprId) -> Option<HirPlace> {
let r = self.place_of_expr_without_adjust(tgt_expr)?;
let default = vec![];
let adjustments = self.result.expr_adjustments.get(&tgt_expr).unwrap_or(&default);
apply_adjusts_to_place(r, adjustments)
apply_adjusts_to_place(&mut self.current_capture_span_stack, r, adjustments)
}
/// Changes `current_capture_span_stack` to contain the stack of spans for this expr.
fn place_of_expr_without_adjust(&mut self, tgt_expr: ExprId) -> Option<HirPlace> {
self.current_capture_span_stack.clear();
match &self.body[tgt_expr] {
Expr::Path(p) => {
let resolver = resolver_for_expr(self.db.upcast(), self.owner, tgt_expr);
if let Some(ResolveValueResult::ValueNs(ValueNs::LocalBinding(b), _)) =
resolver.resolve_path_in_value_ns(self.db.upcast(), p)
{
self.current_capture_span_stack.push(MirSpan::ExprId(tgt_expr));
return Some(HirPlace { local: b, projections: vec![] });
}
}
Expr::Field { expr, name: _ } => {
let mut place = self.place_of_expr(*expr)?;
let field = self.result.field_resolution(tgt_expr)?;
self.current_capture_span_stack.push(MirSpan::ExprId(tgt_expr));
place.projections.push(ProjectionElem::Field(field));
return Some(place);
}
@ -418,6 +433,7 @@ fn place_of_expr_without_adjust(&mut self, tgt_expr: ExprId) -> Option<HirPlace>
TyKind::Ref(..) | TyKind::Raw(..)
) {
let mut place = self.place_of_expr(*expr)?;
self.current_capture_span_stack.push(MirSpan::ExprId(tgt_expr));
place.projections.push(ProjectionElem::Deref);
return Some(place);
}
@ -427,29 +443,65 @@ fn place_of_expr_without_adjust(&mut self, tgt_expr: ExprId) -> Option<HirPlace>
None
}
fn push_capture(&mut self, capture: CapturedItemWithoutTy) {
self.current_captures.push(capture);
fn push_capture(&mut self, place: HirPlace, kind: CaptureKind) {
self.current_captures.push(CapturedItemWithoutTy {
place,
kind,
span_stacks: smallvec![self.current_capture_span_stack.iter().copied().collect()],
});
}
fn ref_expr(&mut self, expr: ExprId) {
if let Some(place) = self.place_of_expr(expr) {
self.add_capture(place, CaptureKind::ByRef(BorrowKind::Shared), expr.into());
fn is_ref_span(&self, span: MirSpan) -> bool {
match span {
MirSpan::ExprId(expr) => matches!(self.body[expr], Expr::Ref { .. }),
MirSpan::BindingId(_) => true,
MirSpan::PatId(_) | MirSpan::SelfParam | MirSpan::Unknown => false,
}
}
fn truncate_capture_spans(&self, capture: &mut CapturedItemWithoutTy, mut truncate_to: usize) {
// The first span is the identifier, and it must always remain.
truncate_to += 1;
for span_stack in &mut capture.span_stacks {
let mut remained = truncate_to;
let mut actual_truncate_to = 0;
for &span in &*span_stack {
actual_truncate_to += 1;
if !self.is_ref_span(span) {
remained -= 1;
if remained == 0 {
break;
}
}
}
if actual_truncate_to < span_stack.len()
&& self.is_ref_span(span_stack[actual_truncate_to])
{
// Include the ref operator if there is one, we will fix it later (in `strip_captures_ref_span()`) if it's incorrect.
actual_truncate_to += 1;
}
span_stack.truncate(actual_truncate_to);
}
}
fn ref_expr(&mut self, expr: ExprId, place: Option<HirPlace>) {
if let Some(place) = place {
self.add_capture(place, CaptureKind::ByRef(BorrowKind::Shared));
}
self.walk_expr(expr);
}
fn add_capture(&mut self, place: HirPlace, kind: CaptureKind, span: MirSpan) {
fn add_capture(&mut self, place: HirPlace, kind: CaptureKind) {
if self.is_upvar(&place) {
self.push_capture(CapturedItemWithoutTy { place, kind, span });
self.push_capture(place, kind);
}
}
fn mutate_expr(&mut self, expr: ExprId) {
if let Some(place) = self.place_of_expr(expr) {
fn mutate_expr(&mut self, expr: ExprId, place: Option<HirPlace>) {
if let Some(place) = place {
self.add_capture(
place,
CaptureKind::ByRef(BorrowKind::Mut { kind: MutBorrowKind::Default }),
expr.into(),
);
}
self.walk_expr(expr);
@ -457,12 +509,12 @@ fn mutate_expr(&mut self, expr: ExprId) {
fn consume_expr(&mut self, expr: ExprId) {
if let Some(place) = self.place_of_expr(expr) {
self.consume_place(place, expr.into());
self.consume_place(place);
}
self.walk_expr(expr);
}
fn consume_place(&mut self, place: HirPlace, span: MirSpan) {
fn consume_place(&mut self, place: HirPlace) {
if self.is_upvar(&place) {
let ty = place.ty(self);
let kind = if self.is_ty_copy(ty) {
@ -470,7 +522,7 @@ fn consume_place(&mut self, place: HirPlace, span: MirSpan) {
} else {
CaptureKind::ByValue
};
self.push_capture(CapturedItemWithoutTy { place, kind, span });
self.push_capture(place, kind);
}
}
@ -501,8 +553,10 @@ fn ref_capture_with_adjusts(&mut self, m: Mutability, tgt_expr: ExprId, rest: &[
Mutability::Not => CaptureKind::ByRef(BorrowKind::Shared),
};
if let Some(place) = self.place_of_expr_without_adjust(tgt_expr) {
if let Some(place) = apply_adjusts_to_place(place, rest) {
self.add_capture(place, capture_kind, tgt_expr.into());
if let Some(place) =
apply_adjusts_to_place(&mut self.current_capture_span_stack, place, rest)
{
self.add_capture(place, capture_kind);
}
}
self.walk_expr_with_adjust(tgt_expr, rest);
@ -584,11 +638,7 @@ fn walk_expr_without_adjust(&mut self, tgt_expr: ExprId) {
self.walk_pat(&mut capture_mode, arm.pat);
}
if let Some(c) = capture_mode {
self.push_capture(CapturedItemWithoutTy {
place: discr_place,
kind: c,
span: (*expr).into(),
})
self.push_capture(discr_place, c);
}
}
}
@ -632,10 +682,11 @@ fn walk_expr_without_adjust(&mut self, tgt_expr: ExprId) {
}
false
};
let place = self.place_of_expr(*expr);
if mutability {
self.mutate_expr(*expr);
self.mutate_expr(*expr, place);
} else {
self.ref_expr(*expr);
self.ref_expr(*expr, place);
}
} else {
self.select_from_expr(*expr);
@ -650,16 +701,22 @@ fn walk_expr_without_adjust(&mut self, tgt_expr: ExprId) {
| Expr::Cast { expr, type_ref: _ } => {
self.consume_expr(*expr);
}
Expr::Ref { expr, rawness: _, mutability } => match mutability {
hir_def::type_ref::Mutability::Shared => self.ref_expr(*expr),
hir_def::type_ref::Mutability::Mut => self.mutate_expr(*expr),
},
Expr::Ref { expr, rawness: _, mutability } => {
// We need to do this before we push the span so the order will be correct.
let place = self.place_of_expr(*expr);
self.current_capture_span_stack.push(MirSpan::ExprId(tgt_expr));
match mutability {
hir_def::type_ref::Mutability::Shared => self.ref_expr(*expr, place),
hir_def::type_ref::Mutability::Mut => self.mutate_expr(*expr, place),
}
}
Expr::BinaryOp { lhs, rhs, op } => {
let Some(op) = op else {
return;
};
if matches!(op, BinaryOp::Assignment { .. }) {
self.mutate_expr(*lhs);
let place = self.place_of_expr(*lhs);
self.mutate_expr(*lhs, place);
self.consume_expr(*rhs);
return;
}
@ -690,7 +747,11 @@ fn walk_expr_without_adjust(&mut self, tgt_expr: ExprId) {
);
let mut cc = mem::take(&mut self.current_captures);
cc.extend(captures.iter().filter(|it| self.is_upvar(&it.place)).map(|it| {
CapturedItemWithoutTy { place: it.place.clone(), kind: it.kind, span: it.span }
CapturedItemWithoutTy {
place: it.place.clone(),
kind: it.kind,
span_stacks: it.span_stacks.clone(),
}
}));
self.current_captures = cc;
}
@ -812,10 +873,13 @@ fn select_from_expr(&mut self, expr: ExprId) {
}
fn restrict_precision_for_unsafe(&mut self) {
for capture in &mut self.current_captures {
// FIXME: Borrow checker problems without this.
let mut current_captures = std::mem::take(&mut self.current_captures);
for capture in &mut current_captures {
let mut ty = self.table.resolve_completely(self.result[capture.place.local].clone());
if ty.as_raw_ptr().is_some() || ty.is_union() {
capture.kind = CaptureKind::ByRef(BorrowKind::Shared);
self.truncate_capture_spans(capture, 0);
capture.place.projections.truncate(0);
continue;
}
@ -830,29 +894,35 @@ fn restrict_precision_for_unsafe(&mut self) {
);
if ty.as_raw_ptr().is_some() || ty.is_union() {
capture.kind = CaptureKind::ByRef(BorrowKind::Shared);
self.truncate_capture_spans(capture, i + 1);
capture.place.projections.truncate(i + 1);
break;
}
}
}
self.current_captures = current_captures;
}
fn adjust_for_move_closure(&mut self) {
for capture in &mut self.current_captures {
// FIXME: Borrow checker won't allow without this.
let mut current_captures = std::mem::take(&mut self.current_captures);
for capture in &mut current_captures {
if let Some(first_deref) =
capture.place.projections.iter().position(|proj| *proj == ProjectionElem::Deref)
{
self.truncate_capture_spans(capture, first_deref);
capture.place.projections.truncate(first_deref);
}
capture.kind = CaptureKind::ByValue;
}
self.current_captures = current_captures;
}
fn minimize_captures(&mut self) {
self.current_captures.sort_by_key(|it| it.place.projections.len());
self.current_captures.sort_unstable_by_key(|it| it.place.projections.len());
let mut hash_map = FxHashMap::<HirPlace, usize>::default();
let result = mem::take(&mut self.current_captures);
for item in result {
for mut item in result {
let mut lookup_place = HirPlace { local: item.place.local, projections: vec![] };
let mut it = item.place.projections.iter();
let prev_index = loop {
@ -860,12 +930,17 @@ fn minimize_captures(&mut self) {
break Some(*k);
}
match it.next() {
Some(it) => lookup_place.projections.push(it.clone()),
Some(it) => {
lookup_place.projections.push(it.clone());
}
None => break None,
}
};
match prev_index {
Some(p) => {
let prev_projections_len = self.current_captures[p].place.projections.len();
self.truncate_capture_spans(&mut item, prev_projections_len);
self.current_captures[p].span_stacks.extend(item.span_stacks);
let len = self.current_captures[p].place.projections.len();
let kind_after_truncate =
item.place.capture_kind_of_truncated_place(item.kind, len);
@ -880,31 +955,32 @@ fn minimize_captures(&mut self) {
}
}
fn consume_with_pat(&mut self, mut place: HirPlace, pat: PatId) {
let cnt = self.result.pat_adjustments.get(&pat).map(|it| it.len()).unwrap_or_default();
place.projections = place
.projections
.iter()
.cloned()
.chain((0..cnt).map(|_| ProjectionElem::Deref))
.collect::<Vec<_>>();
match &self.body[pat] {
fn consume_with_pat(&mut self, mut place: HirPlace, tgt_pat: PatId) {
let adjustments_count =
self.result.pat_adjustments.get(&tgt_pat).map(|it| it.len()).unwrap_or_default();
place.projections.extend((0..adjustments_count).map(|_| ProjectionElem::Deref));
self.current_capture_span_stack
.extend((0..adjustments_count).map(|_| MirSpan::PatId(tgt_pat)));
'reset_span_stack: {
match &self.body[tgt_pat] {
Pat::Missing | Pat::Wild => (),
Pat::Tuple { args, ellipsis } => {
let (al, ar) = args.split_at(ellipsis.map_or(args.len(), |it| it as usize));
let field_count = match self.result[pat].kind(Interner) {
let field_count = match self.result[tgt_pat].kind(Interner) {
TyKind::Tuple(_, s) => s.len(Interner),
_ => return,
_ => break 'reset_span_stack,
};
let fields = 0..field_count;
let it = al.iter().zip(fields.clone()).chain(ar.iter().rev().zip(fields.rev()));
for (arg, i) in it {
for (&arg, i) in it {
let mut p = place.clone();
self.current_capture_span_stack.push(MirSpan::PatId(arg));
p.projections.push(ProjectionElem::Field(Either::Right(TupleFieldId {
tuple: TupleId(!0), // dummy this, as its unused anyways
index: i as u32,
})));
self.consume_with_pat(p, *arg);
self.consume_with_pat(p, arg);
self.current_capture_span_stack.pop();
}
}
Pat::Or(pats) => {
@ -913,12 +989,12 @@ fn consume_with_pat(&mut self, mut place: HirPlace, pat: PatId) {
}
}
Pat::Record { args, .. } => {
let Some(variant) = self.result.variant_resolution_for_pat(pat) else {
return;
let Some(variant) = self.result.variant_resolution_for_pat(tgt_pat) else {
break 'reset_span_stack;
};
match variant {
VariantId::EnumVariantId(_) | VariantId::UnionId(_) => {
self.consume_place(place, pat.into())
self.consume_place(place)
}
VariantId::StructId(s) => {
let vd = &*self.db.struct_data(s).variant_data;
@ -928,11 +1004,13 @@ fn consume_with_pat(&mut self, mut place: HirPlace, pat: PatId) {
continue;
};
let mut p = place.clone();
self.current_capture_span_stack.push(MirSpan::PatId(arg));
p.projections.push(ProjectionElem::Field(Either::Left(FieldId {
parent: variant,
local_id,
})));
self.consume_with_pat(p, arg);
self.current_capture_span_stack.pop();
}
}
}
@ -941,53 +1019,65 @@ fn consume_with_pat(&mut self, mut place: HirPlace, pat: PatId) {
| Pat::Slice { .. }
| Pat::ConstBlock(_)
| Pat::Path(_)
| Pat::Lit(_) => self.consume_place(place, pat.into()),
Pat::Bind { id: _, subpat: _ } => {
let mode = self.result.binding_modes[pat];
| Pat::Lit(_) => self.consume_place(place),
&Pat::Bind { id, subpat: _ } => {
let mode = self.result.binding_modes[tgt_pat];
let capture_kind = match mode {
BindingMode::Move => {
self.consume_place(place, pat.into());
return;
self.consume_place(place);
break 'reset_span_stack;
}
BindingMode::Ref(Mutability::Not) => BorrowKind::Shared,
BindingMode::Ref(Mutability::Mut) => {
BorrowKind::Mut { kind: MutBorrowKind::Default }
}
};
self.add_capture(place, CaptureKind::ByRef(capture_kind), pat.into());
self.current_capture_span_stack.push(MirSpan::BindingId(id));
self.add_capture(place, CaptureKind::ByRef(capture_kind));
self.current_capture_span_stack.pop();
}
Pat::TupleStruct { path: _, args, ellipsis } => {
let Some(variant) = self.result.variant_resolution_for_pat(pat) else {
return;
let Some(variant) = self.result.variant_resolution_for_pat(tgt_pat) else {
break 'reset_span_stack;
};
match variant {
VariantId::EnumVariantId(_) | VariantId::UnionId(_) => {
self.consume_place(place, pat.into())
self.consume_place(place)
}
VariantId::StructId(s) => {
let vd = &*self.db.struct_data(s).variant_data;
let (al, ar) = args.split_at(ellipsis.map_or(args.len(), |it| it as usize));
let (al, ar) =
args.split_at(ellipsis.map_or(args.len(), |it| it as usize));
let fields = vd.fields().iter();
let it =
al.iter().zip(fields.clone()).chain(ar.iter().rev().zip(fields.rev()));
for (arg, (i, _)) in it {
let it = al
.iter()
.zip(fields.clone())
.chain(ar.iter().rev().zip(fields.rev()));
for (&arg, (i, _)) in it {
let mut p = place.clone();
self.current_capture_span_stack.push(MirSpan::PatId(arg));
p.projections.push(ProjectionElem::Field(Either::Left(FieldId {
parent: variant,
local_id: i,
})));
self.consume_with_pat(p, *arg);
self.consume_with_pat(p, arg);
self.current_capture_span_stack.pop();
}
}
}
}
Pat::Ref { pat, mutability: _ } => {
self.current_capture_span_stack.push(MirSpan::PatId(tgt_pat));
place.projections.push(ProjectionElem::Deref);
self.consume_with_pat(place, *pat)
self.consume_with_pat(place, *pat);
self.current_capture_span_stack.pop();
}
Pat::Box { .. } => (), // not supported
}
}
self.current_capture_span_stack
.truncate(self.current_capture_span_stack.len() - adjustments_count);
}
fn consume_exprs(&mut self, exprs: impl Iterator<Item = ExprId>) {
for expr in exprs {
@ -1044,12 +1134,28 @@ fn analyze_closure(&mut self, closure: ClosureId) -> FnTrait {
CaptureBy::Ref => (),
}
self.minimize_captures();
self.strip_captures_ref_span();
let result = mem::take(&mut self.current_captures);
let captures = result.into_iter().map(|it| it.with_ty(self)).collect::<Vec<_>>();
self.result.closure_info.insert(closure, (captures, closure_kind));
closure_kind
}
fn strip_captures_ref_span(&mut self) {
// FIXME: Borrow checker won't allow without this.
let mut captures = std::mem::take(&mut self.current_captures);
for capture in &mut captures {
if matches!(capture.kind, CaptureKind::ByValue) {
for span_stack in &mut capture.span_stacks {
if self.is_ref_span(span_stack[span_stack.len() - 1]) {
span_stack.truncate(span_stack.len() - 1);
}
}
}
}
self.current_captures = captures;
}
pub(crate) fn infer_closures(&mut self) {
let deferred_closures = self.sort_closures();
for (closure, exprs) in deferred_closures.into_iter().rev() {
@ -1110,10 +1216,17 @@ fn sort_closures(&mut self) -> Vec<(ClosureId, Vec<(Ty, Ty, Vec<Ty>, ExprId)>)>
}
}
fn apply_adjusts_to_place(mut r: HirPlace, adjustments: &[Adjustment]) -> Option<HirPlace> {
/// Call this only when the last span in the stack isn't a split.
fn apply_adjusts_to_place(
current_capture_span_stack: &mut Vec<MirSpan>,
mut r: HirPlace,
adjustments: &[Adjustment],
) -> Option<HirPlace> {
let span = *current_capture_span_stack.last().expect("empty capture span stack");
for adj in adjustments {
match &adj.kind {
Adjust::Deref(None) => {
current_capture_span_stack.push(span);
r.projections.push(ProjectionElem::Deref);
}
_ => return None,

View File

@ -636,6 +636,7 @@ pub enum TerminatorKind {
},
}
// Order of variants in this enum matter: they are used to compare borrow kinds.
#[derive(Debug, PartialEq, Eq, Clone, Copy, PartialOrd, Ord)]
pub enum BorrowKind {
/// Data must be immutable and is aliasable.
@ -666,15 +667,16 @@ pub enum BorrowKind {
Mut { kind: MutBorrowKind },
}
// Order of variants in this enum matter: they are used to compare borrow kinds.
#[derive(Debug, PartialEq, Eq, Clone, Copy, PartialOrd, Ord)]
pub enum MutBorrowKind {
/// Data must be immutable but not aliasable. This kind of borrow cannot currently
/// be expressed by the user and is used only in implicit closure bindings.
ClosureCapture,
Default,
/// This borrow arose from method-call auto-ref
/// (i.e., adjustment::Adjust::Borrow).
TwoPhasedBorrow,
/// Data must be immutable but not aliasable. This kind of borrow cannot currently
/// be expressed by the user and is used only in implicit closure bindings.
ClosureCapture,
}
impl BorrowKind {

View File

@ -1180,8 +1180,15 @@ fn lower_expr_to_place_without_adjust(
let placeholder_subst = self.placeholder_subst();
let tmp_ty =
capture.ty.clone().substitute(Interner, &placeholder_subst);
let tmp: Place = self.temp(tmp_ty, current, capture.span)?.into();
self.push_assignment(current, tmp, Rvalue::Ref(*bk, p), capture.span);
// FIXME: Handle more than one span.
let capture_spans = capture.spans();
let tmp: Place = self.temp(tmp_ty, current, capture_spans[0])?.into();
self.push_assignment(
current,
tmp,
Rvalue::Ref(*bk, p),
capture_spans[0],
);
operands.push(Operand::Move(tmp));
}
CaptureKind::ByValue => operands.push(Operand::Move(p)),

View File

@ -1,3 +1,4 @@
mod closure_captures;
mod coercion;
mod diagnostics;
mod display_source_code;

View File

@ -0,0 +1,433 @@
use base_db::salsa::InternKey;
use expect_test::{expect, Expect};
use hir_def::db::DefDatabase;
use hir_expand::files::InFileWrapper;
use itertools::Itertools;
use span::{HirFileId, TextRange};
use syntax::{AstNode, AstPtr};
use test_fixture::WithFixture;
use crate::db::{HirDatabase, InternedClosureId};
use crate::display::HirDisplay;
use crate::mir::MirSpan;
use crate::test_db::TestDB;
use super::visit_module;
fn check_closure_captures(ra_fixture: &str, expect: Expect) {
let (db, file_id) = TestDB::with_single_file(ra_fixture);
let module = db.module_for_file(file_id);
let def_map = module.def_map(&db);
let mut defs = Vec::new();
visit_module(&db, &def_map, module.local_id, &mut |it| defs.push(it));
let mut captures_info = Vec::new();
for def in defs {
let infer = db.infer(def);
let db = &db;
captures_info.extend(infer.closure_info.iter().flat_map(|(closure_id, (captures, _))| {
let closure = db.lookup_intern_closure(InternedClosureId::from_intern_id(closure_id.0));
let (_, source_map) = db.body_with_source_map(closure.0);
let closure_text_range = source_map
.expr_syntax(closure.1)
.expect("failed to map closure to SyntaxNode")
.value
.text_range();
captures.iter().map(move |capture| {
fn text_range<N: AstNode>(
db: &TestDB,
syntax: InFileWrapper<HirFileId, AstPtr<N>>,
) -> TextRange {
let root = syntax.file_syntax(db);
syntax.value.to_node(&root).syntax().text_range()
}
// FIXME: Deduplicate this with hir::Local::sources().
let (body, source_map) = db.body_with_source_map(closure.0);
let local_text_range = match body.self_param.zip(source_map.self_param_syntax()) {
Some((param, source)) if param == capture.local() => {
format!("{:?}", text_range(db, source))
}
_ => source_map
.patterns_for_binding(capture.local())
.iter()
.map(|&definition| {
text_range(db, source_map.pat_syntax(definition).unwrap())
})
.map(|it| format!("{it:?}"))
.join(", "),
};
let place = capture.display_place(closure.0, db);
let capture_ty = capture.ty.skip_binders().display_test(db).to_string();
let spans = capture
.spans()
.iter()
.flat_map(|span| match *span {
MirSpan::ExprId(expr) => {
vec![text_range(db, source_map.expr_syntax(expr).unwrap())]
}
MirSpan::PatId(pat) => {
vec![text_range(db, source_map.pat_syntax(pat).unwrap())]
}
MirSpan::BindingId(binding) => source_map
.patterns_for_binding(binding)
.iter()
.map(|pat| text_range(db, source_map.pat_syntax(*pat).unwrap()))
.collect(),
MirSpan::SelfParam => {
vec![text_range(db, source_map.self_param_syntax().unwrap())]
}
MirSpan::Unknown => Vec::new(),
})
.sorted_by_key(|it| it.start())
.map(|it| format!("{it:?}"))
.join(",");
(closure_text_range, local_text_range, spans, place, capture_ty, capture.kind())
})
}));
}
captures_info.sort_unstable_by_key(|(closure_text_range, local_text_range, ..)| {
(closure_text_range.start(), local_text_range.clone())
});
let rendered = captures_info
.iter()
.map(|(closure_text_range, local_text_range, spans, place, capture_ty, capture_kind)| {
format!(
"{closure_text_range:?};{local_text_range};{spans} {capture_kind:?} {place} {capture_ty}"
)
})
.join("\n");
expect.assert_eq(&rendered);
}
#[test]
fn deref_in_let() {
check_closure_captures(
r#"
//- minicore:copy
fn main() {
let a = &mut true;
let closure = || { let b = *a; };
}
"#,
expect!["53..71;20..21;66..68 ByRef(Shared) *a &'? bool"],
);
}
#[test]
fn deref_then_ref_pattern() {
check_closure_captures(
r#"
//- minicore:copy
fn main() {
let a = &mut true;
let closure = || { let &mut ref b = a; };
}
"#,
expect!["53..79;20..21;67..72 ByRef(Shared) *a &'? bool"],
);
check_closure_captures(
r#"
//- minicore:copy
fn main() {
let a = &mut true;
let closure = || { let &mut ref mut b = a; };
}
"#,
expect!["53..83;20..21;67..76 ByRef(Mut { kind: Default }) *a &'? mut bool"],
);
}
#[test]
fn unique_borrow() {
check_closure_captures(
r#"
//- minicore:copy
fn main() {
let a = &mut true;
let closure = || { *a = false; };
}
"#,
expect!["53..71;20..21;58..60 ByRef(Mut { kind: Default }) *a &'? mut bool"],
);
}
#[test]
fn deref_ref_mut() {
check_closure_captures(
r#"
//- minicore:copy
fn main() {
let a = &mut true;
let closure = || { let ref mut b = *a; };
}
"#,
expect!["53..79;20..21;62..71 ByRef(Mut { kind: Default }) *a &'? mut bool"],
);
}
#[test]
fn let_else_not_consuming() {
check_closure_captures(
r#"
//- minicore:copy
fn main() {
let a = &mut true;
let closure = || { let _ = *a else { return; }; };
}
"#,
expect!["53..88;20..21;66..68 ByRef(Shared) *a &'? bool"],
);
}
#[test]
fn consume() {
check_closure_captures(
r#"
//- minicore:copy
struct NonCopy;
fn main() {
let a = NonCopy;
let closure = || { let b = a; };
}
"#,
expect!["67..84;36..37;80..81 ByValue a NonCopy"],
);
}
#[test]
fn ref_to_upvar() {
check_closure_captures(
r#"
//- minicore:copy
struct NonCopy;
fn main() {
let mut a = NonCopy;
let closure = || { let b = &a; };
let closure = || { let c = &mut a; };
}
"#,
expect![[r#"
71..89;36..41;84..86 ByRef(Shared) a &'? NonCopy
109..131;36..41;122..128 ByRef(Mut { kind: Default }) a &'? mut NonCopy"#]],
);
}
#[test]
fn field() {
check_closure_captures(
r#"
//- minicore:copy
struct Foo { a: i32, b: i32 }
fn main() {
let a = Foo { a: 0, b: 0 };
let closure = || { let b = a.a; };
}
"#,
expect!["92..111;50..51;105..108 ByRef(Shared) a.a &'? i32"],
);
}
#[test]
fn fields_different_mode() {
check_closure_captures(
r#"
//- minicore:copy
struct NonCopy;
struct Foo { a: i32, b: i32, c: NonCopy, d: bool }
fn main() {
let mut a = Foo { a: 0, b: 0 };
let closure = || {
let b = &a.a;
let c = &mut a.b;
let d = a.c;
};
}
"#,
expect![[r#"
133..212;87..92;154..158 ByRef(Shared) a.a &'? i32
133..212;87..92;176..184 ByRef(Mut { kind: Default }) a.b &'? mut i32
133..212;87..92;202..205 ByValue a.c NonCopy"#]],
);
}
#[test]
fn autoref() {
check_closure_captures(
r#"
//- minicore:copy
struct Foo;
impl Foo {
fn imm(&self) {}
fn mut_(&mut self) {}
}
fn main() {
let mut a = Foo;
let closure = || a.imm();
let closure = || a.mut_();
}
"#,
expect![[r#"
123..133;92..97;126..127 ByRef(Shared) a &'? Foo
153..164;92..97;156..157 ByRef(Mut { kind: Default }) a &'? mut Foo"#]],
);
}
#[test]
fn captures_priority() {
check_closure_captures(
r#"
//- minicore:copy
struct NonCopy;
fn main() {
let mut a = &mut true;
// Max ByRef(Mut { kind: Default })
let closure = || {
*a = false;
let b = &mut a;
};
// Max ByValue
let mut a = NonCopy;
let closure = || {
let b = a;
let c = &mut a;
let d = &a;
};
}
"#,
expect![[r#"
113..167;36..41;127..128,154..160 ByRef(Mut { kind: Default }) a &'? mut &'? mut bool
231..304;196..201;252..253,276..277,296..297 ByValue a NonCopy"#]],
);
}
#[test]
fn let_underscore() {
check_closure_captures(
r#"
//- minicore:copy
fn main() {
let mut a = true;
let closure = || { let _ = a; };
}
"#,
expect![""],
);
}
#[test]
fn match_wildcard() {
check_closure_captures(
r#"
//- minicore:copy
struct NonCopy;
fn main() {
let mut a = NonCopy;
let closure = || match a {
_ => {}
};
let closure = || match a {
ref b => {}
};
let closure = || match a {
ref mut b => {}
};
}
"#,
expect![[r#"
125..163;36..41;134..135 ByRef(Shared) a &'? NonCopy
183..225;36..41;192..193 ByRef(Mut { kind: Default }) a &'? mut NonCopy"#]],
);
}
#[test]
fn multiple_bindings() {
check_closure_captures(
r#"
//- minicore:copy
fn main() {
let mut a = false;
let mut closure = || { let (b | b) = a; };
}
"#,
expect!["57..80;20..25;76..77,76..77 ByRef(Shared) a &'? bool"],
);
}
#[test]
fn multiple_usages() {
check_closure_captures(
r#"
//- minicore:copy
fn main() {
let mut a = false;
let mut closure = || {
let b = &a;
let c = &a;
let d = &mut a;
a = true;
};
}
"#,
expect!["57..149;20..25;78..80,98..100,118..124,134..135 ByRef(Mut { kind: Default }) a &'? mut bool"],
);
}
#[test]
fn ref_then_deref() {
check_closure_captures(
r#"
//- minicore:copy
fn main() {
let mut a = false;
let mut closure = || { let b = *&mut a; };
}
"#,
expect!["57..80;20..25;71..77 ByRef(Mut { kind: Default }) a &'? mut bool"],
);
}
#[test]
fn ref_of_ref() {
check_closure_captures(
r#"
//- minicore:copy
fn main() {
let mut a = &false;
let closure = || { let b = &a; };
let closure = || { let b = &mut a; };
let a = &mut false;
let closure = || { let b = &a; };
let closure = || { let b = &mut a; };
}
"#,
expect![[r#"
54..72;20..25;67..69 ByRef(Shared) a &'? &'? bool
92..114;20..25;105..111 ByRef(Mut { kind: Default }) a &'? mut &'? bool
158..176;124..125;171..173 ByRef(Shared) a &'? &'? mut bool
196..218;124..125;209..215 ByRef(Mut { kind: Default }) a &'? mut &'? mut bool"#]],
);
}
#[test]
fn multiple_capture_usages() {
check_closure_captures(
r#"
//- minicore:copy
struct A { a: i32, b: bool }
fn main() {
let mut a = A { a: 123, b: false };
let closure = |$0| {
let b = a.b;
a = A { a: 456, b: true };
};
closure();
}
"#,
expect!["99..165;49..54;120..121,133..134 ByRef(Mut { kind: Default }) a &'? mut A"],
);
}

View File

@ -78,7 +78,7 @@
use itertools::Itertools;
use nameres::diagnostics::DefDiagnosticKind;
use rustc_hash::FxHashSet;
use span::{Edition, EditionedFileId, FileId, MacroCallId};
use span::{Edition, EditionedFileId, FileId, MacroCallId, SyntaxContextId};
use stdx::{impl_from, never};
use syntax::{
ast::{self, HasAttrs as _, HasGenericParams, HasName},
@ -4133,6 +4133,7 @@ pub fn display_place(&self, db: &dyn HirDatabase) -> String {
}
}
#[derive(Clone, Copy, PartialEq, Eq)]
pub enum CaptureKind {
SharedRef,
UniqueSharedRef,
@ -4378,6 +4379,22 @@ pub fn impls_into_future(&self, db: &dyn HirDatabase) -> bool {
method_resolution::implements_trait(&canonical_ty, db, &self.env, trait_)
}
/// This does **not** resolve `IntoFuture`, only `Future`.
pub fn future_output(self, db: &dyn HirDatabase) -> Option<Type> {
let future_output =
db.lang_item(self.env.krate, LangItem::FutureOutput)?.as_type_alias()?;
self.normalize_trait_assoc_type(db, &[], future_output.into())
}
/// This does **not** resolve `IntoIterator`, only `Iterator`.
pub fn iterator_item(self, db: &dyn HirDatabase) -> Option<Type> {
let iterator_trait = db.lang_item(self.env.krate, LangItem::Iterator)?.as_trait()?;
let iterator_item = db
.trait_data(iterator_trait)
.associated_type_by_name(&Name::new_symbol(sym::Item.clone(), SyntaxContextId::ROOT))?;
self.normalize_trait_assoc_type(db, &[], iterator_item.into())
}
/// Checks that particular type `ty` implements `std::ops::FnOnce`.
///
/// This function can be used to check if a particular type is callable, since FnOnce is a

View File

@ -1617,6 +1617,7 @@ fn format_function(
fun.control_flow.is_async,
fun.mods.is_const,
fun.control_flow.is_unsafe,
false,
)
}

View File

@ -122,6 +122,7 @@ pub(crate) fn generate_delegate_methods(acc: &mut Assists, ctx: &AssistContext<'
let is_async = method_source.async_token().is_some();
let is_const = method_source.const_token().is_some();
let is_unsafe = method_source.unsafe_token().is_some();
let is_gen = method_source.gen_token().is_some();
let fn_name = make::name(&name);
@ -154,6 +155,7 @@ pub(crate) fn generate_delegate_methods(acc: &mut Assists, ctx: &AssistContext<'
is_async,
is_const,
is_unsafe,
is_gen,
)
.clone_for_update();

View File

@ -740,6 +740,7 @@ fn func_assoc_item(
item.async_token().is_some(),
item.const_token().is_some(),
item.unsafe_token().is_some(),
item.gen_token().is_some(),
)
.clone_for_update();

View File

@ -365,6 +365,7 @@ fn render(self, cap: Option<SnippetCap>, edit: &mut SourceChangeBuilder) -> ast:
self.is_async,
false, // FIXME : const and unsafe are not handled yet.
false,
false,
)
.clone_for_update();

View File

@ -261,7 +261,19 @@ fn generate_getter_from_info(
let ret_type = Some(make::ret_type(ty));
let body = make::block_expr([], Some(body));
make::fn_(strukt.visibility(), fn_name, None, None, params, body, ret_type, false, false, false)
make::fn_(
strukt.visibility(),
fn_name,
None,
None,
params,
body,
ret_type,
false,
false,
false,
false,
)
}
fn generate_setter_from_info(info: &AssistInfo, record_field_info: &RecordFieldInfo) -> ast::Fn {
@ -285,7 +297,19 @@ fn generate_setter_from_info(info: &AssistInfo, record_field_info: &RecordFieldI
let body = make::block_expr([assign_stmt.into()], None);
// Make the setter fn
make::fn_(strukt.visibility(), fn_name, None, None, params, body, None, false, false, false)
make::fn_(
strukt.visibility(),
fn_name,
None,
None,
params,
body,
None,
false,
false,
false,
false,
)
}
fn extract_and_parse(

View File

@ -115,6 +115,7 @@ pub(crate) fn generate_new(acc: &mut Assists, ctx: &AssistContext<'_>) -> Option
false,
false,
false,
false,
)
.clone_for_update();
fn_.indent(1.into());

View File

@ -1,7 +1,7 @@
use itertools::Itertools;
use syntax::{
ast::{self, make, AstNode, AstToken},
match_ast, ted, NodeOrToken, SyntaxElement, TextRange, TextSize, T,
match_ast, ted, Edition, NodeOrToken, SyntaxElement, TextRange, TextSize, T,
};
use crate::{AssistContext, AssistId, AssistKind, Assists};
@ -77,7 +77,7 @@ fn compute_dbg_replacement(macro_expr: ast::MacroExpr) -> Option<(TextRange, Opt
let input_expressions = input_expressions
.into_iter()
.filter_map(|(is_sep, group)| (!is_sep).then_some(group))
.map(|mut tokens| syntax::hacks::parse_expr_from_str(&tokens.join("")))
.map(|mut tokens| syntax::hacks::parse_expr_from_str(&tokens.join(""), Edition::CURRENT))
.collect::<Option<Vec<ast::Expr>>>()?;
let parent = macro_expr.syntax().parent()?;

View File

@ -14,7 +14,7 @@
use itertools::Itertools;
use syntax::{
ast::{self, AttrKind},
AstNode, SyntaxKind, T,
AstNode, Edition, SyntaxKind, T,
};
use crate::{
@ -373,7 +373,9 @@ fn parse_comma_sep_expr(input: ast::TokenTree) -> Option<Vec<ast::Expr>> {
input_expressions
.into_iter()
.filter_map(|(is_sep, group)| (!is_sep).then_some(group))
.filter_map(|mut tokens| syntax::hacks::parse_expr_from_str(&tokens.join("")))
.filter_map(|mut tokens| {
syntax::hacks::parse_expr_from_str(&tokens.join(""), Edition::CURRENT)
})
.collect::<Vec<ast::Expr>>(),
)
}

View File

@ -477,10 +477,12 @@ pub fn parse_tt_as_comma_sep_paths(
.into_iter()
.filter_map(|(is_sep, group)| (!is_sep).then_some(group))
.filter_map(|mut tokens| {
syntax::hacks::parse_expr_from_str(&tokens.join("")).and_then(|expr| match expr {
syntax::hacks::parse_expr_from_str(&tokens.join(""), Edition::CURRENT).and_then(
|expr| match expr {
ast::Expr::PathExpr(it) => it.path(),
_ => None,
})
},
)
})
.collect();
Some(paths)

View File

@ -8465,7 +8465,7 @@ impl Iterator for S {
file_id: FileId(
1,
),
full_range: 7800..8008,
full_range: 7800..8042,
focus_range: 7865..7871,
name: "Future",
kind: Trait,
@ -8479,8 +8479,8 @@ impl Iterator for S {
file_id: FileId(
1,
),
full_range: 8638..9104,
focus_range: 8682..8690,
full_range: 8672..9171,
focus_range: 8749..8757,
name: "Iterator",
kind: Trait,
container_name: "iterator",

View File

@ -240,6 +240,7 @@ pub(super) fn prefill() -> DashMap<SymbolProxy, (), BuildHasherDefault<FxHasher>
fundamental,
future_trait,
future,
future_output,
Future,
ge,
get_context,
@ -274,6 +275,7 @@ pub(super) fn prefill() -> DashMap<SymbolProxy, (), BuildHasherDefault<FxHasher>
iter_mut,
iter,
Iterator,
iterator,
keyword,
lang,
le,

View File

@ -190,7 +190,7 @@ UseTreeList =
Fn =
Attr* Visibility?
'default'? 'const'? 'async'? 'unsafe'? Abi?
'default'? 'const'? 'async'? 'gen'? 'unsafe'? Abi?
'fn' Name GenericParamList? ParamList RetType? WhereClause?
(body:BlockExpr | ';')

View File

@ -8,7 +8,7 @@
ted, AstToken, NodeOrToken, SyntaxElement, SyntaxNode, SyntaxToken,
};
#[derive(Debug, Clone, Copy)]
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub struct IndentLevel(pub u8);
impl From<u8> for IndentLevel {

View File

@ -486,6 +486,8 @@ pub fn default_token(&self) -> Option<SyntaxToken> { support::token(&self.syntax
#[inline]
pub fn fn_token(&self) -> Option<SyntaxToken> { support::token(&self.syntax, T![fn]) }
#[inline]
pub fn gen_token(&self) -> Option<SyntaxToken> { support::token(&self.syntax, T![gen]) }
#[inline]
pub fn unsafe_token(&self) -> Option<SyntaxToken> { support::token(&self.syntax, T![unsafe]) }
}

View File

@ -1035,6 +1035,7 @@ pub fn fn_(
is_async: bool,
is_const: bool,
is_unsafe: bool,
is_gen: bool,
) -> ast::Fn {
let type_params = match type_params {
Some(type_params) => format!("{type_params}"),
@ -1056,9 +1057,10 @@ pub fn fn_(
let async_literal = if is_async { "async " } else { "" };
let const_literal = if is_const { "const " } else { "" };
let unsafe_literal = if is_unsafe { "unsafe " } else { "" };
let gen_literal = if is_gen { "gen " } else { "" };
ast_from_text(&format!(
"{visibility}{async_literal}{const_literal}{unsafe_literal}fn {fn_name}{type_params}{params} {ret_type}{where_clause}{body}",
"{visibility}{const_literal}{async_literal}{gen_literal}{unsafe_literal}fn {fn_name}{type_params}{params} {ret_type}{where_clause}{body}",
))
}
pub fn struct_(

View File

@ -17,7 +17,7 @@
ted, NodeOrToken, SmolStr, SyntaxElement, SyntaxToken, TokenText, T,
};
use super::{RangeItem, RangeOp};
use super::{GenericParam, RangeItem, RangeOp};
impl ast::Lifetime {
pub fn text(&self) -> TokenText<'_> {
@ -822,6 +822,15 @@ pub enum TypeOrConstParam {
Const(ast::ConstParam),
}
impl From<TypeOrConstParam> for GenericParam {
fn from(value: TypeOrConstParam) -> Self {
match value {
TypeOrConstParam::Type(it) => GenericParam::TypeParam(it),
TypeOrConstParam::Const(it) => GenericParam::ConstParam(it),
}
}
}
impl TypeOrConstParam {
pub fn name(&self) -> Option<ast::Name> {
match self {

View File

@ -6,9 +6,9 @@
use crate::{ast, AstNode};
pub fn parse_expr_from_str(s: &str) -> Option<ast::Expr> {
pub fn parse_expr_from_str(s: &str, edition: Edition) -> Option<ast::Expr> {
let s = s.trim();
let file = ast::SourceFile::parse(&format!("const _: () = {s};"), Edition::CURRENT);
let file = ast::SourceFile::parse(&format!("const _: () = {s};"), edition);
let expr = file.syntax_node().descendants().find_map(ast::Expr::cast)?;
if expr.syntax().text() != s {
return None;

View File

@ -1196,6 +1196,7 @@ pub mod future {
#[doc(notable_trait)]
#[lang = "future_trait"]
pub trait Future {
#[lang = "future_output"]
type Output;
#[lang = "poll"]
fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output>;
@ -1293,6 +1294,7 @@ fn next(&mut self) -> Option<A> {
mod traits {
mod iterator {
#[doc(notable_trait)]
#[lang = "iterator"]
pub trait Iterator {
type Item;
#[lang = "next"]