if r.is_erased() { tcx.lifetimes.re_static } else { r }
});
let span = ast_ty.span;
- tcx.sess.emit_err(TypeofReservedKeywordUsed {
- span,
- ty,
- opt_sugg: Some((span, Applicability::MachineApplicable))
- .filter(|_| ty.is_suggestable(tcx, false)),
- });
+ let (ty, opt_sugg) = if let Some(ty) = ty.make_suggestable(tcx, false) {
+ (ty, Some((span, Applicability::MachineApplicable)))
+ } else {
+ (ty, None)
+ };
+ tcx.sess.emit_err(TypeofReservedKeywordUsed { span, ty, opt_sugg });
ty
}
visitor.visit_ty(ty);
let mut diag = bad_placeholder(tcx, visitor.0, "return type");
let ret_ty = fn_sig.output();
- if ret_ty.is_suggestable(tcx, false) {
+ if let Some(ret_ty) = ret_ty.make_suggestable(tcx, false) {
diag.span_suggestion(
ty.span,
"replace with the correct return type",
ret_ty,
Applicability::MachineApplicable,
);
- } else if matches!(ret_ty.kind(), ty::FnDef(..)) {
- let fn_sig = ret_ty.fn_sig(tcx);
- if fn_sig
- .skip_binder()
- .inputs_and_output
- .iter()
- .all(|t| t.is_suggestable(tcx, false))
- {
- diag.span_suggestion(
- ty.span,
- "replace with the correct return type",
- fn_sig,
- Applicability::MachineApplicable,
- );
- }
+ } else if matches!(ret_ty.kind(), ty::FnDef(..))
+ && let Some(fn_sig) = ret_ty.fn_sig(tcx).make_suggestable(tcx, false)
+ {
+ diag.span_suggestion(
+ ty.span,
+ "replace with the correct return type",
+ fn_sig,
+ Applicability::MachineApplicable,
+ );
} else if let Some(sugg) = suggest_impl_trait(tcx, ret_ty, ty.span, hir_id, def_id) {
diag.span_suggestion(
ty.span,
let trait_name = tcx.item_name(trait_def_id);
let args_tuple = substs.type_at(1);
let ty::Tuple(types) = *args_tuple.kind() else { return None; };
- if !types.is_suggestable(tcx, false) {
- return None;
- }
+ let types = types.make_suggestable(tcx, false)?;
let maybe_ret =
if item_ty.is_unit() { String::new() } else { format!(" -> {item_ty}") };
Some(format!(
// FIXME(compiler-errors): We may benefit from resolving regions here.
if ocx.select_where_possible().is_empty()
&& let item_ty = infcx.resolve_vars_if_possible(item_ty)
- && item_ty.is_suggestable(tcx, false)
+ && let Some(item_ty) = item_ty.make_suggestable(tcx, false)
&& let Some(sugg) = formatter(tcx, infcx.resolve_vars_if_possible(substs), trait_def_id, assoc_item_def_id, item_ty)
{
return Some(sugg);
use rustc_middle::ty::print::with_forced_trimmed_paths;
use rustc_middle::ty::subst::InternalSubsts;
use rustc_middle::ty::util::IntTypeExt;
-use rustc_middle::ty::{self, DefIdTree, Ty, TyCtxt, TypeFolder, TypeSuperFoldable, TypeVisitable};
+use rustc_middle::ty::{
+ self, DefIdTree, IsSuggestable, Ty, TyCtxt, TypeFolder, TypeSuperFoldable, TypeVisitable,
+};
use rustc_span::symbol::Ident;
use rustc_span::{Span, DUMMY_SP};
) -> Ty<'a> {
// Attempts to make the type nameable by turning FnDefs into FnPtrs.
struct MakeNameable<'tcx> {
- success: bool,
tcx: TyCtxt<'tcx>,
}
- impl<'tcx> MakeNameable<'tcx> {
- fn new(tcx: TyCtxt<'tcx>) -> Self {
- MakeNameable { success: true, tcx }
- }
- }
-
impl<'tcx> TypeFolder<'tcx> for MakeNameable<'tcx> {
fn tcx(&self) -> TyCtxt<'tcx> {
self.tcx
}
fn fold_ty(&mut self, ty: Ty<'tcx>) -> Ty<'tcx> {
- if !self.success {
- return ty;
- }
-
- match ty.kind() {
+ let ty = match *ty.kind() {
ty::FnDef(def_id, substs) => {
- self.tcx.mk_fn_ptr(self.tcx.fn_sig(*def_id).subst(self.tcx, substs))
+ self.tcx.mk_fn_ptr(self.tcx.fn_sig(def_id).subst(self.tcx, substs))
}
- // FIXME: non-capturing closures should also suggest a function pointer
- ty::Closure(..) | ty::Generator(..) => {
- self.success = false;
- ty
- }
- _ => ty.super_fold_with(self),
- }
+ _ => ty,
+ };
+
+ ty.super_fold_with(self)
}
}
suggestions.clear();
}
- // Suggesting unnameable types won't help.
- let mut mk_nameable = MakeNameable::new(tcx);
- let ty = mk_nameable.fold_ty(ty);
- let sugg_ty = if mk_nameable.success { Some(ty) } else { None };
- if let Some(sugg_ty) = sugg_ty {
+ if let Some(ty) = ty.make_suggestable(tcx, false) {
err.span_suggestion(
span,
&format!("provide a type for the {item}", item = kind),
- format!("{colon} {sugg_ty}"),
+ format!("{colon} {ty}"),
Applicability::MachineApplicable,
);
} else {
let mut diag = bad_placeholder(tcx, vec![span], kind);
if !ty.references_error() {
- let mut mk_nameable = MakeNameable::new(tcx);
- let ty = mk_nameable.fold_ty(ty);
- let sugg_ty = if mk_nameable.success { Some(ty) } else { None };
- if let Some(sugg_ty) = sugg_ty {
+ if let Some(ty) = ty.make_suggestable(tcx, false) {
diag.span_suggestion(
span,
"replace with the correct type",
- sugg_ty,
- Applicability::MaybeIncorrect,
+ ty,
+ Applicability::MachineApplicable,
);
} else {
with_forced_trimmed_paths!(diag.span_note(
return true;
}
&hir::FnRetTy::DefaultReturn(span) if expected.is_unit() => {
- if found.is_suggestable(self.tcx, false) {
+ if let Some(found) = found.make_suggestable(self.tcx, false) {
err.subdiagnostic(AddReturnTypeSuggestion::Add { span, found: found.to_string() });
return true;
} else if let ty::Closure(_, substs) = found.kind()
if let Some(output_def_id) = output_def_id
&& let Some(trait_def_id) = trait_def_id
&& self.tcx.parent(output_def_id) == trait_def_id
- && output_ty.is_suggestable(self.tcx, false)
+ && let Some(output_ty) = output_ty.make_suggestable(self.tcx, false)
{
- Some(("Output", *output_ty))
+ Some(("Output", output_ty))
} else {
None
}
use proc_macro::bridge::client::ProcMacro;
use std::ops::Fn;
use std::path::Path;
+use std::time::Duration;
use std::{cmp, env};
#[derive(Clone)]
) -> Result<&'static [ProcMacro], CrateError> {
// Make sure the path contains a / or the linker will search for it.
let path = env::current_dir().unwrap().join(path);
- let lib = unsafe { libloading::Library::new(path) }
- .map_err(|err| CrateError::DlOpen(err.to_string()))?;
+ let lib = load_dylib(&path, 5).map_err(|err| CrateError::DlOpen(err))?;
let sym_name = self.sess.generate_proc_macro_decls_symbol(stable_crate_id);
let sym = unsafe { lib.get::<*const &[ProcMacro]>(sym_name.as_bytes()) }
visit::walk_crate(&mut f, krate);
f.spans
}
+
+// On Windows the compiler would sometimes intermittently fail to open the
+// proc-macro DLL with `Error::LoadLibraryExW`. It is suspected that something in the
+// system still holds a lock on the file, so we retry a few times before calling it
+// an error.
+fn load_dylib(path: &Path, max_attempts: usize) -> Result<libloading::Library, String> {
+ assert!(max_attempts > 0);
+
+ let mut last_error = None;
+
+ for attempt in 0..max_attempts {
+ match unsafe { libloading::Library::new(&path) } {
+ Ok(lib) => {
+ if attempt > 0 {
+ debug!(
+ "Loaded proc-macro `{}` after {} attempts.",
+ path.display(),
+ attempt + 1
+ );
+ }
+ return Ok(lib);
+ }
+ Err(err) => {
+ // Only try to recover from this specific error.
+ if !matches!(err, libloading::Error::LoadLibraryExW { .. }) {
+ return Err(err.to_string());
+ }
+
+ last_error = Some(err);
+ std::thread::sleep(Duration::from_millis(100));
+ debug!("Failed to load proc-macro `{}`. Retrying.", path.display());
+ }
+ }
+ }
+
+ debug!("Failed to load proc-macro `{}` even after {} attempts.", path.display(), max_attempts);
+ Err(format!("{} (retried {} times)", last_error.unwrap(), max_attempts))
+}
[decode] trait_impl_trait_tys: rustc_data_structures::fx::FxHashMap<rustc_hir::def_id::DefId, rustc_middle::ty::Ty<'tcx>>,
[] bit_set_u32: rustc_index::bit_set::BitSet<u32>,
+ [] external_constraints: rustc_middle::traits::solve::ExternalConstraintsData<'tcx>,
]);
)
}
mod chalk;
pub mod query;
pub mod select;
+pub mod solve;
pub mod specialization_graph;
mod structural_impls;
pub mod util;
--- /dev/null
+use std::ops::ControlFlow;
+
+use rustc_data_structures::intern::Interned;
+
+use crate::ty::{FallibleTypeFolder, Ty, TypeFoldable, TypeFolder, TypeVisitable, TypeVisitor};
+
+#[derive(Debug, PartialEq, Eq, Copy, Clone, Hash)]
+pub struct ExternalConstraints<'tcx>(pub(crate) Interned<'tcx, ExternalConstraintsData<'tcx>>);
+
+impl<'tcx> std::ops::Deref for ExternalConstraints<'tcx> {
+ type Target = ExternalConstraintsData<'tcx>;
+
+ fn deref(&self) -> &Self::Target {
+ &*self.0
+ }
+}
+
+/// Additional constraints returned on success.
+#[derive(Debug, PartialEq, Eq, Clone, Hash, Default)]
+pub struct ExternalConstraintsData<'tcx> {
+ // FIXME: implement this.
+ pub regions: (),
+ pub opaque_types: Vec<(Ty<'tcx>, Ty<'tcx>)>,
+}
+
+impl<'tcx> TypeFoldable<'tcx> for ExternalConstraints<'tcx> {
+ fn try_fold_with<F: FallibleTypeFolder<'tcx>>(self, folder: &mut F) -> Result<Self, F::Error> {
+ Ok(FallibleTypeFolder::tcx(folder).intern_external_constraints(ExternalConstraintsData {
+ regions: (),
+ opaque_types: self
+ .opaque_types
+ .iter()
+ .map(|opaque| opaque.try_fold_with(folder))
+ .collect::<Result<_, F::Error>>()?,
+ }))
+ }
+
+ fn fold_with<F: TypeFolder<'tcx>>(self, folder: &mut F) -> Self {
+ TypeFolder::tcx(folder).intern_external_constraints(ExternalConstraintsData {
+ regions: (),
+ opaque_types: self.opaque_types.iter().map(|opaque| opaque.fold_with(folder)).collect(),
+ })
+ }
+}
+
+impl<'tcx> TypeVisitable<'tcx> for ExternalConstraints<'tcx> {
+ fn visit_with<V: TypeVisitor<'tcx>>(
+ &self,
+ visitor: &mut V,
+ ) -> std::ops::ControlFlow<V::BreakTy> {
+ self.regions.visit_with(visitor)?;
+ self.opaque_types.visit_with(visitor)?;
+ ControlFlow::Continue(())
+ }
+}
};
use crate::thir::Thir;
use crate::traits;
+use crate::traits::solve::{ExternalConstraints, ExternalConstraintsData};
use crate::ty::query::{self, TyCtxtAt};
use crate::ty::{
self, AdtDef, AdtDefData, AdtKind, Binder, Const, ConstData, DefIdTree, FloatTy, FloatVar,
bound_variable_kinds: InternedSet<'tcx, List<ty::BoundVariableKind>>,
layout: InternedSet<'tcx, LayoutS<VariantIdx>>,
adt_def: InternedSet<'tcx, AdtDefData>,
+ external_constraints: InternedSet<'tcx, ExternalConstraintsData<'tcx>>,
}
impl<'tcx> CtxtInterners<'tcx> {
bound_variable_kinds: Default::default(),
layout: Default::default(),
adt_def: Default::default(),
+ external_constraints: Default::default(),
}
}
const_allocation: intern_const_alloc(Allocation): ConstAllocation -> ConstAllocation<'tcx>,
layout: intern_layout(LayoutS<VariantIdx>): Layout -> Layout<'tcx>,
adt_def: intern_adt_def(AdtDefData): AdtDef -> AdtDef<'tcx>,
+ external_constraints: intern_external_constraints(ExternalConstraintsData<'tcx>): ExternalConstraints -> ExternalConstraints<'tcx>,
}
macro_rules! slice_interners {
use std::ops::ControlFlow;
use crate::ty::{
- visit::TypeVisitable, AliasTy, Const, ConstKind, DefIdTree, InferConst, InferTy, Opaque,
- PolyTraitPredicate, Projection, Ty, TyCtxt, TypeSuperVisitable, TypeVisitor,
+ visit::TypeVisitable, AliasTy, Const, ConstKind, DefIdTree, FallibleTypeFolder, InferConst,
+ InferTy, Opaque, PolyTraitPredicate, Projection, Ty, TyCtxt, TypeFoldable, TypeSuperFoldable,
+ TypeSuperVisitable, TypeVisitor,
};
use rustc_data_structures::fx::FxHashMap;
}
}
-pub trait IsSuggestable<'tcx> {
+pub trait IsSuggestable<'tcx>: Sized {
/// Whether this makes sense to suggest in a diagnostic.
///
/// We filter out certain types and constants since they don't provide
/// Only if `infer_suggestable` is true, we consider type and const
/// inference variables to be suggestable.
fn is_suggestable(self, tcx: TyCtxt<'tcx>, infer_suggestable: bool) -> bool;
+
+ fn make_suggestable(self, tcx: TyCtxt<'tcx>, infer_suggestable: bool) -> Option<Self>;
}
impl<'tcx, T> IsSuggestable<'tcx> for T
where
- T: TypeVisitable<'tcx>,
+ T: TypeVisitable<'tcx> + TypeFoldable<'tcx>,
{
fn is_suggestable(self, tcx: TyCtxt<'tcx>, infer_suggestable: bool) -> bool {
self.visit_with(&mut IsSuggestableVisitor { tcx, infer_suggestable }).is_continue()
}
+
+ fn make_suggestable(self, tcx: TyCtxt<'tcx>, infer_suggestable: bool) -> Option<T> {
+ self.try_fold_with(&mut MakeSuggestableFolder { tcx, infer_suggestable }).ok()
+ }
}
pub fn suggest_arbitrary_trait_bound<'tcx>(
c.super_visit_with(self)
}
}
+
+pub struct MakeSuggestableFolder<'tcx> {
+ tcx: TyCtxt<'tcx>,
+ infer_suggestable: bool,
+}
+
+impl<'tcx> FallibleTypeFolder<'tcx> for MakeSuggestableFolder<'tcx> {
+ type Error = ();
+
+ fn tcx(&self) -> TyCtxt<'tcx> {
+ self.tcx
+ }
+
+ fn try_fold_ty(&mut self, t: Ty<'tcx>) -> Result<Ty<'tcx>, Self::Error> {
+ let t = match *t.kind() {
+ Infer(InferTy::TyVar(_)) if self.infer_suggestable => t,
+
+ FnDef(def_id, substs) => {
+ self.tcx.mk_fn_ptr(self.tcx.fn_sig(def_id).subst(self.tcx, substs))
+ }
+
+ // FIXME(compiler-errors): We could replace these with infer, I guess.
+ Closure(..)
+ | Infer(..)
+ | Generator(..)
+ | GeneratorWitness(..)
+ | Bound(_, _)
+ | Placeholder(_)
+ | Error(_) => {
+ return Err(());
+ }
+
+ Alias(Opaque, AliasTy { def_id, .. }) => {
+ let parent = self.tcx.parent(def_id);
+ if let hir::def::DefKind::TyAlias | hir::def::DefKind::AssocTy = self.tcx.def_kind(parent)
+ && let Alias(Opaque, AliasTy { def_id: parent_opaque_def_id, .. }) = *self.tcx.type_of(parent).kind()
+ && parent_opaque_def_id == def_id
+ {
+ t
+ } else {
+ return Err(());
+ }
+ }
+
+ Param(param) => {
+ // FIXME: It would be nice to make this not use string manipulation,
+ // but it's pretty hard to do this, since `ty::ParamTy` is missing
+ // sufficient info to determine if it is synthetic, and we don't
+ // always have a convenient way of getting `ty::Generics` at the call
+ // sites we invoke `IsSuggestable::is_suggestable`.
+ if param.name.as_str().starts_with("impl ") {
+ return Err(());
+ }
+
+ t
+ }
+
+ _ => t,
+ };
+
+ t.try_super_fold_with(self)
+ }
+
+ fn try_fold_const(&mut self, c: Const<'tcx>) -> Result<Const<'tcx>, ()> {
+ let c = match c.kind() {
+ ConstKind::Infer(InferConst::Var(_)) if self.infer_suggestable => c,
+
+ ConstKind::Infer(..)
+ | ConstKind::Bound(..)
+ | ConstKind::Placeholder(..)
+ | ConstKind::Error(..) => {
+ return Err(());
+ }
+
+ _ => c,
+ };
+
+ c.try_super_fold_with(self)
+ }
+}
/// the infallible methods of this trait to ensure that the two APIs
/// are coherent.
pub trait TypeFolder<'tcx>: FallibleTypeFolder<'tcx, Error = !> {
- fn tcx<'a>(&'a self) -> TyCtxt<'tcx>;
+ fn tcx(&self) -> TyCtxt<'tcx>;
fn fold_binder<T>(&mut self, t: Binder<'tcx, T>) -> Binder<'tcx, T>
where
ClosureBinder::NotPresent
};
- let constness = self.parse_constness(Case::Sensitive);
+ let constness = self.parse_closure_constness(Case::Sensitive);
let movability =
if self.eat_keyword(kw::Static) { Movability::Static } else { Movability::Movable };
fn check_const_closure(&self) -> bool {
self.is_keyword_ahead(0, &[kw::Const])
&& self.look_ahead(1, |t| match &t.kind {
- token::Ident(kw::Move | kw::Static | kw::Async, _)
- | token::OrOr
- | token::BinOp(token::Or) => true,
+ // async closures do not work with const closures, so we do not parse that here.
+ token::Ident(kw::Move | kw::Static, _) | token::OrOr | token::BinOp(token::Or) => {
+ true
+ }
_ => false,
})
}
/// Parses constness: `const` or nothing.
fn parse_constness(&mut self, case: Case) -> Const {
- // Avoid const blocks to be parsed as const items
- if self.look_ahead(1, |t| t != &token::OpenDelim(Delimiter::Brace))
+ self.parse_constness_(case, false)
+ }
+
+ /// Parses constness for closures
+ fn parse_closure_constness(&mut self, case: Case) -> Const {
+ self.parse_constness_(case, true)
+ }
+
+ fn parse_constness_(&mut self, case: Case, is_closure: bool) -> Const {
+ // Avoid const blocks and const closures to be parsed as const items
+ if (self.check_const_closure() == is_closure)
+ && self.look_ahead(1, |t| t != &token::OpenDelim(Delimiter::Brace))
&& self.eat_keyword_case(kw::Const, case)
{
Const::Yes(self.prev_token.uninterpolated_span())
use rustc_infer::traits::query::NoSolution;
use rustc_infer::traits::Obligation;
use rustc_middle::infer::canonical::Certainty as OldCertainty;
-use rustc_middle::ty::{self, Ty, TyCtxt};
+use rustc_middle::traits::solve::{ExternalConstraints, ExternalConstraintsData};
+use rustc_middle::ty::{self, TyCtxt};
use rustc_middle::ty::{
CoercePredicate, RegionOutlivesPredicate, SubtypePredicate, ToPredicate, TypeOutlivesPredicate,
};
Goal { param_env: obligation.param_env, predicate: obligation.predicate }
}
}
-
-#[derive(Debug, PartialEq, Eq, Clone, Hash, TypeFoldable, TypeVisitable)]
+#[derive(Debug, PartialEq, Eq, Clone, Copy, Hash, TypeFoldable, TypeVisitable)]
pub struct Response<'tcx> {
pub var_values: CanonicalVarValues<'tcx>,
/// Additional constraints returned by this query.
Overflow,
}
-/// Additional constraints returned on success.
-#[derive(Debug, PartialEq, Eq, Clone, Hash, TypeFoldable, TypeVisitable, Default)]
-pub struct ExternalConstraints<'tcx> {
- // FIXME: implement this.
- regions: (),
- opaque_types: Vec<(Ty<'tcx>, Ty<'tcx>)>,
-}
-
type CanonicalGoal<'tcx, T = ty::Predicate<'tcx>> = Canonical<'tcx, Goal<'tcx, T>>;
type CanonicalResponse<'tcx> = Canonical<'tcx, Response<'tcx>>;
/// The result of evaluating a canonical query.
EvalCtxt { infcx, var_values, search_graph, in_projection_eq_hack: false };
let result = ecx.compute_goal(goal);
- // FIXME: `Response` should be `Copy`
- if search_graph.try_finalize_goal(tcx, canonical_goal, result.clone()) {
+ if search_graph.try_finalize_goal(tcx, canonical_goal, result) {
return result;
}
}
}
fn make_canonical_response(&self, certainty: Certainty) -> QueryResult<'tcx> {
- let external_constraints = take_external_constraints(self.infcx)?;
+ let external_constraints = compute_external_query_constraints(self.infcx)?;
Ok(self.infcx.canonicalize_response(Response {
var_values: self.var_values,
}
#[instrument(level = "debug", skip(infcx), ret)]
-fn take_external_constraints<'tcx>(
+fn compute_external_query_constraints<'tcx>(
infcx: &InferCtxt<'tcx>,
) -> Result<ExternalConstraints<'tcx>, NoSolution> {
let region_obligations = infcx.take_registered_region_obligations();
let opaque_types = infcx.take_opaque_types_for_query_response();
- Ok(ExternalConstraints {
+ Ok(infcx.tcx.intern_external_constraints(ExternalConstraintsData {
// FIXME: Now that's definitely wrong :)
//
// Should also do the leak check here I think
regions: drop(region_obligations),
opaque_types,
- })
+ }))
}
fn instantiate_canonical_query_response<'tcx>(
Certainty::Yes => OldCertainty::Proven,
Certainty::Maybe(_) => OldCertainty::Ambiguous,
},
- opaque_types: resp.external_constraints.opaque_types,
+ // FIXME: This to_owned makes me sad, but we should eventually impl
+ // `instantiate_query_response_and_region_obligations` separately
+ // instead of piggybacking off of the old implementation.
+ opaque_types: resp.external_constraints.opaque_types.to_owned(),
value: resp.certainty,
}),
) else { bug!(); };
variables: goal.variables,
value: Response {
var_values: CanonicalVarValues::make_identity(tcx, goal.variables),
- external_constraints: Default::default(),
+ // FIXME: maybe we should store the "no response" version in tcx, like
+ // we do for tcx.types and stuff.
+ external_constraints: tcx
+ .intern_external_constraints(ExternalConstraintsData::default()),
certainty,
},
})
}
pub(super) fn provisional_result(&self, entry_index: EntryIndex) -> QueryResult<'tcx> {
- // FIXME: Responses should probably be `Copy` as well
- self.entries[entry_index].response.clone()
+ self.entries[entry_index].response
}
}
#![stable(feature = "rust1", since = "1.0.0")]
-use crate::const_closure::ConstFnMutClosure;
use crate::marker::Destruct;
use self::Ordering::*;
F: ~const Destruct,
K: ~const Destruct,
{
- const fn imp<T, F: ~const FnMut(&T) -> K, K: ~const Ord>(
- f: &mut F,
- (v1, v2): (&T, &T),
- ) -> Ordering
- where
- T: ~const Destruct,
- K: ~const Destruct,
- {
- f(v1).cmp(&f(v2))
- }
- max_by(v1, v2, ConstFnMutClosure::new(&mut f, imp))
+ max_by(v1, v2, const |v1, v2| f(v1).cmp(&f(v2)))
}
// Implementation of PartialEq, Eq, PartialOrd and Ord for primitive types
+++ /dev/null
-use crate::marker::Destruct;
-use crate::marker::Tuple;
-
-/// Struct representing a closure with mutably borrowed data.
-///
-/// Example:
-/// ```no_build
-/// #![feature(const_mut_refs)]
-/// use crate::const_closure::ConstFnMutClosure;
-/// const fn imp(state: &mut i32, (arg,): (i32,)) -> i32 {
-/// *state += arg;
-/// *state
-/// }
-/// let mut i = 5;
-/// let mut cl = ConstFnMutClosure::new(&mut i, imp);
-///
-/// assert!(7 == cl(2));
-/// assert!(8 == cl(1));
-/// ```
-pub(crate) struct ConstFnMutClosure<CapturedData, Function> {
- /// The Data captured by the Closure.
- /// Must be either a (mutable) reference or a tuple of (mutable) references.
- pub data: CapturedData,
- /// The Function of the Closure, must be: Fn(CapturedData, ClosureArgs) -> ClosureReturn
- pub func: Function,
-}
-impl<'a, CapturedData: ?Sized, Function> ConstFnMutClosure<&'a mut CapturedData, Function> {
- /// Function for creating a new closure.
- ///
- /// `data` is the a mutable borrow of data that is captured from the environment.
- /// If you want Data to be a tuple of mutable Borrows, the struct must be constructed manually.
- ///
- /// `func` is the function of the closure, it gets the data and a tuple of the arguments closure
- /// and return the return value of the closure.
- pub(crate) const fn new<ClosureArguments, ClosureReturnValue>(
- data: &'a mut CapturedData,
- func: Function,
- ) -> Self
- where
- Function: ~const Fn(&mut CapturedData, ClosureArguments) -> ClosureReturnValue,
- {
- Self { data, func }
- }
-}
-
-macro_rules! impl_fn_mut_tuple {
- ($($var:ident)*) => {
- #[allow(unused_parens)]
- impl<'a, $($var,)* ClosureArguments: Tuple, Function, ClosureReturnValue> const
- FnOnce<ClosureArguments> for ConstFnMutClosure<($(&'a mut $var),*), Function>
- where
- Function: ~const Fn(($(&mut $var),*), ClosureArguments) -> ClosureReturnValue+ ~const Destruct,
- {
- type Output = ClosureReturnValue;
-
- extern "rust-call" fn call_once(mut self, args: ClosureArguments) -> Self::Output {
- self.call_mut(args)
- }
- }
- #[allow(unused_parens)]
- impl<'a, $($var,)* ClosureArguments: Tuple, Function, ClosureReturnValue> const
- FnMut<ClosureArguments> for ConstFnMutClosure<($(&'a mut $var),*), Function>
- where
- Function: ~const Fn(($(&mut $var),*), ClosureArguments)-> ClosureReturnValue,
- {
- extern "rust-call" fn call_mut(&mut self, args: ClosureArguments) -> Self::Output {
- #[allow(non_snake_case)]
- let ($($var),*) = &mut self.data;
- (self.func)(($($var),*), args)
- }
- }
- };
-}
-impl_fn_mut_tuple!(A);
-impl_fn_mut_tuple!(A B);
-impl_fn_mut_tuple!(A B C);
-impl_fn_mut_tuple!(A B C D);
-impl_fn_mut_tuple!(A B C D E);
use crate::array;
-use crate::const_closure::ConstFnMutClosure;
use crate::iter::{ByRefSized, FusedIterator, Iterator, TrustedRandomAccessNoCoerce};
use crate::mem::{self, MaybeUninit};
use crate::ops::{ControlFlow, NeverShortCircuit, Try};
I: Iterator,
{
#[inline]
- default fn fold<B, F>(mut self, init: B, mut f: F) -> B
+ default fn fold<B, F>(mut self, init: B, f: F) -> B
where
Self: Sized,
F: FnMut(B, Self::Item) -> B,
{
- let fold = ConstFnMutClosure::new(&mut f, NeverShortCircuit::wrap_mut_2_imp);
- self.try_fold(init, fold).0
+ self.try_fold(init, NeverShortCircuit::wrap_mut_2(f)).0
}
}
-use crate::{
- const_closure::ConstFnMutClosure,
- ops::{NeverShortCircuit, Try},
-};
+use crate::ops::{NeverShortCircuit, Try};
/// Like `Iterator::by_ref`, but requiring `Sized` so it can forward generics.
///
}
#[inline]
- fn fold<B, F>(self, init: B, mut f: F) -> B
+ fn fold<B, F>(self, init: B, f: F) -> B
where
F: FnMut(B, Self::Item) -> B,
{
// `fold` needs ownership, so this can't forward directly.
- I::try_fold(self.0, init, ConstFnMutClosure::new(&mut f, NeverShortCircuit::wrap_mut_2_imp))
- .0
+ I::try_fold(self.0, init, NeverShortCircuit::wrap_mut_2(f)).0
}
#[inline]
}
#[inline]
- fn rfold<B, F>(self, init: B, mut f: F) -> B
+ fn rfold<B, F>(self, init: B, f: F) -> B
where
F: FnMut(B, Self::Item) -> B,
{
// `rfold` needs ownership, so this can't forward directly.
- I::try_rfold(
- self.0,
- init,
- ConstFnMutClosure::new(&mut f, NeverShortCircuit::wrap_mut_2_imp),
- )
- .0
+ I::try_rfold(self.0, init, NeverShortCircuit::wrap_mut_2(f)).0
}
#[inline]
};
(@internal $fold:ident -> $try_fold:ident) => {
#[inline]
- fn $fold<AAA, FFF>(mut self, init: AAA, mut fold: FFF) -> AAA
+ fn $fold<AAA, FFF>(mut self, init: AAA, fold: FFF) -> AAA
where
FFF: FnMut(AAA, Self::Item) -> AAA,
{
- use crate::const_closure::ConstFnMutClosure;
use crate::ops::NeverShortCircuit;
- let fold = ConstFnMutClosure::new(&mut fold, NeverShortCircuit::wrap_mut_2_imp);
- self.$try_fold(init, fold).0
+ self.$try_fold(init, NeverShortCircuit::wrap_mut_2(fold)).0
}
};
}
mod tuple;
mod unit;
-mod const_closure;
-
#[stable(feature = "core_primitive", since = "1.43.0")]
pub mod primitive;
pub(crate) struct NeverShortCircuit<T>(pub T);
impl<T> NeverShortCircuit<T> {
- /// Implementation for building `ConstFnMutClosure` for wrapping the output of a ~const FnMut in a `NeverShortCircuit`.
#[inline]
- pub const fn wrap_mut_2_imp<A, B, F: ~const FnMut(A, B) -> T>(
- f: &mut F,
- (a, b): (A, B),
- ) -> NeverShortCircuit<T> {
- NeverShortCircuit(f(a, b))
+ pub fn wrap_mut_2<A, B>(
+ mut f: impl ~const FnMut(A, B) -> T,
+ ) -> impl ~const FnMut(A, B) -> Self {
+ cfg_if! {
+ if #[cfg(bootstrap)] {
+ #[allow(unused_parens)]
+ (const move |a, b| NeverShortCircuit(f(a, b)))
+ } else {
+ const move |a, b| NeverShortCircuit(f(a, b))
+ }
+ }
}
}
// Transforming contained values
/////////////////////////////////////////////////////////////////////////
- /// Maps an `Option<T>` to `Option<U>` by applying a function to a contained value.
+ /// Maps an `Option<T>` to `Option<U>` by applying a function to a contained value (if `Some`) or returns `None` (if `None`).
///
/// # Examples
///
/// let maybe_some_string = Some(String::from("Hello, World!"));
/// // `Option::map` takes self *by value*, consuming `maybe_some_string`
/// let maybe_some_len = maybe_some_string.map(|s| s.len());
- ///
/// assert_eq!(maybe_some_len, Some(13));
+ ///
+ /// let x: Option<&str> = None;
+ /// assert_eq!(x.map(|s| s.len()), None);
/// ```
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
// doesn't accidentally get printed.
#[cfg_attr(test, derive(Debug))]
enum ErrorData<C> {
- Os(i32),
+ Os(RawOsError),
Simple(ErrorKind),
SimpleMessage(&'static SimpleMessage),
Custom(C),
}
+/// The type of raw OS error codes returned by [`Error::raw_os_error`].
+///
+/// This is an [`i32`] on all currently supported platforms, but platforms
+/// added in the future (such as UEFI) may use a different primitive type like
+/// [`usize`]. Use `as`or [`into`] conversions where applicable to ensure maximum
+/// portability.
+///
+/// [`into`]: Into::into
+#[unstable(feature = "raw_os_error_ty", issue = "none")]
+pub type RawOsError = i32;
+
// `#[repr(align(4))]` is probably redundant, it should have that value or
// higher already. We include it just because repr_bitpacked.rs's encoding
// requires an alignment >= 4 (note that `#[repr(align)]` will not reduce the
#[must_use]
#[inline]
pub fn last_os_error() -> Error {
- Error::from_raw_os_error(sys::os::errno() as i32)
+ Error::from_raw_os_error(sys::os::errno())
}
/// Creates a new instance of an [`Error`] from a particular OS error code.
#[stable(feature = "rust1", since = "1.0.0")]
#[must_use]
#[inline]
- pub fn from_raw_os_error(code: i32) -> Error {
+ pub fn from_raw_os_error(code: RawOsError) -> Error {
Error { repr: Repr::new_os(code) }
}
#[stable(feature = "rust1", since = "1.0.0")]
#[must_use]
#[inline]
- pub fn raw_os_error(&self) -> Option<i32> {
+ pub fn raw_os_error(&self) -> Option<RawOsError> {
match self.repr.data() {
ErrorData::Os(i) => Some(i),
ErrorData::Custom(..) => None,
//! to use a pointer type to store something that may hold an integer, some of
//! the time.
-use super::{Custom, ErrorData, ErrorKind, SimpleMessage};
+use super::{Custom, ErrorData, ErrorKind, RawOsError, SimpleMessage};
use alloc::boxed::Box;
use core::marker::PhantomData;
use core::mem::{align_of, size_of};
}
#[inline]
- pub(super) fn new_os(code: i32) -> Self {
+ pub(super) fn new_os(code: RawOsError) -> Self {
let utagged = ((code as usize) << 32) | TAG_OS;
// Safety: `TAG_OS` is not zero, so the result of the `|` is not 0.
let res = Self(unsafe { NonNull::new_unchecked(ptr::invalid_mut(utagged)) }, PhantomData);
let bits = ptr.as_ptr().addr();
match bits & TAG_MASK {
TAG_OS => {
- let code = ((bits as i64) >> 32) as i32;
+ let code = ((bits as i64) >> 32) as RawOsError;
ErrorData::Os(code)
}
TAG_SIMPLE => {
static_assert!(align_of::<SimpleMessage>() >= TAG_MASK + 1);
static_assert!(align_of::<Custom>() >= TAG_MASK + 1);
+// `RawOsError` must be an alias for `i32`.
+const _: fn(RawOsError) -> i32 = |os| os;
+
static_assert!(@usize_eq: TAG_MASK & TAG_SIMPLE_MESSAGE, TAG_SIMPLE_MESSAGE);
static_assert!(@usize_eq: TAG_MASK & TAG_CUSTOM, TAG_CUSTOM);
static_assert!(@usize_eq: TAG_MASK & TAG_OS, TAG_OS);
//! non-64bit targets, where the packed 64 bit representation wouldn't work, and
//! would have no benefit.
-use super::{Custom, ErrorData, ErrorKind, SimpleMessage};
+use super::{Custom, ErrorData, ErrorKind, RawOsError, SimpleMessage};
use alloc::boxed::Box;
type Inner = ErrorData<Box<Custom>>;
Self(Inner::Custom(b))
}
#[inline]
- pub(super) fn new_os(code: i32) -> Self {
+ pub(super) fn new_os(code: RawOsError) -> Self {
Self(Inner::Os(code))
}
#[inline]
#[test]
fn test_os_packing() {
- for code in -20i32..20i32 {
+ for code in -20..20 {
let e = Error::from_raw_os_error(code);
assert_eq!(e.raw_os_error(), Some(code));
assert_matches!(
#[stable(feature = "bufwriter_into_parts", since = "1.56.0")]
pub use self::buffered::WriterPanicked;
+#[unstable(feature = "raw_os_error_ty", issue = "none")]
+pub use self::error::RawOsError;
pub(crate) use self::stdio::attempt_print_to_stderr;
#[unstable(feature = "internal_output_capture", issue = "none")]
#[doc(no_inline, hidden)]
if f.alternate() {
write!(f, ": {:#}", print_generic_bounds(bounds, cx))?;
} else {
- write!(f, ": {}", print_generic_bounds(bounds, cx))?;
+ write!(f, ": {}", print_generic_bounds(bounds, cx))?;
}
}
if f.alternate() {
write!(f, " = {:#}", ty.print(cx))?;
} else {
- write!(f, " = {}", ty.print(cx))?;
+ write!(f, " = {}", ty.print(cx))?;
}
}
if f.alternate() {
write!(f, "const {}: {:#}", self.name, ty.print(cx))?;
} else {
- write!(f, "const {}: {}", self.name, ty.print(cx))?;
+ write!(f, "const {}: {}", self.name, ty.print(cx))?;
}
if let Some(default) = default {
if f.alternate() {
write!(f, " = {:#}", default)?;
} else {
- write!(f, " = {}", default)?;
+ write!(f, " = {}", default)?;
}
}
let mut br_with_padding = String::with_capacity(6 * indent + 28);
br_with_padding.push_str("<br>");
for _ in 0..indent + 4 {
- br_with_padding.push_str(" ");
+ br_with_padding.push_str(" ");
}
let where_preds = where_preds.to_string().replace("<br>", &br_with_padding);
if ending == Ending::Newline {
- let mut clause = " ".repeat(indent.saturating_sub(1));
+ let mut clause = " ".repeat(indent.saturating_sub(1));
write!(clause, "<span class=\"where fmt-newline\">where{where_preds},</span>")?;
clause
} else {
format!("<br><span class=\"where\">where{where_preds}</span>")
} else {
let mut clause = br_with_padding;
- clause.truncate(clause.len() - 4 * " ".len());
+ clause.truncate(clause.len() - 4);
write!(clause, "<span class=\"where\">where{where_preds}</span>")?;
clause
}
let declaration_len = header_len + args_plain.len() + arrow_plain.len();
let output = if declaration_len > 80 {
- let full_pad = format!("<br>{}", " ".repeat(indent + 4));
- let close_pad = format!("<br>{}", " ".repeat(indent));
+ let full_pad = format!("<br>{}", " ".repeat(indent + 4));
+ let close_pad = format!("<br>{}", " ".repeat(indent));
format!(
"({pad}{args}{close}){arrow}",
pad = if self.inputs.values.is_empty() { "" } else { &full_pad },
if f.alternate() {
write!(f, ": {:#}", print_generic_bounds(bounds, cx))?;
} else {
- write!(f, ": {}", print_generic_bounds(bounds, cx))?;
+ write!(f, ": {}", print_generic_bounds(bounds, cx))?;
}
}
}
fn print_tuple_struct_fields(w: &mut Buffer, cx: &Context<'_>, s: &[clean::Item]) {
for (i, ty) in s.iter().enumerate() {
if i > 0 {
- w.write_str(", ");
+ w.write_str(", ");
}
match *ty.kind {
clean::StrippedItem(box clean::StructFieldItem(_)) => w.write_str("_"),
"<div class=\"sub-variant-field\">\
<span id=\"{id}\" class=\"small-section-header\">\
<a href=\"#{id}\" class=\"anchor field\">ยง</a>\
- <code>{f}: {t}</code>\
+ <code>{f}: {t}</code>\
</span>",
id = id,
f = field.name.unwrap(),
font-weight: 600;
margin: 0;
padding: 0;
+ white-space: pre-wrap;
}
#crate-search,
.fn .where,
.where.fmt-newline {
display: block;
+ white-space: pre-wrap;
font-size: 0.875rem;
}
-<script type="text/json" id="notable-traits-data">{"SomeStruct":"<h3>Notable traits for <code><a class=\"struct\" href=\"struct.SomeStruct.html\" title=\"struct doc_notable_trait::SomeStruct\">SomeStruct</a></code></h3><pre><code><span class=\"where fmt-newline\">impl <a class=\"trait\" href=\"trait.SomeTrait.html\" title=\"trait doc_notable_trait::SomeTrait\">SomeTrait</a> for <a class=\"struct\" href=\"struct.SomeStruct.html\" title=\"struct doc_notable_trait::SomeStruct\">SomeStruct</a></span>","Wrapper<Self>":"<h3>Notable traits for <code><a class=\"struct\" href=\"struct.Wrapper.html\" title=\"struct doc_notable_trait::Wrapper\">Wrapper</a>&lt;T&gt;</code></h3><pre><code><span class=\"where fmt-newline\">impl&lt;T:&nbsp;<a class=\"trait\" href=\"trait.SomeTrait.html\" title=\"trait doc_notable_trait::SomeTrait\">SomeTrait</a>&gt; <a class=\"trait\" href=\"trait.SomeTrait.html\" title=\"trait doc_notable_trait::SomeTrait\">SomeTrait</a> for <a class=\"struct\" href=\"struct.Wrapper.html\" title=\"struct doc_notable_trait::Wrapper\">Wrapper</a>&lt;T&gt;</span>"}</script>
\ No newline at end of file
+<script type="text/json" id="notable-traits-data">{"SomeStruct":"<h3>Notable traits for <code><a class=\"struct\" href=\"struct.SomeStruct.html\" title=\"struct doc_notable_trait::SomeStruct\">SomeStruct</a></code></h3><pre><code><span class=\"where fmt-newline\">impl <a class=\"trait\" href=\"trait.SomeTrait.html\" title=\"trait doc_notable_trait::SomeTrait\">SomeTrait</a> for <a class=\"struct\" href=\"struct.SomeStruct.html\" title=\"struct doc_notable_trait::SomeStruct\">SomeStruct</a></span>","Wrapper<Self>":"<h3>Notable traits for <code><a class=\"struct\" href=\"struct.Wrapper.html\" title=\"struct doc_notable_trait::Wrapper\">Wrapper</a>&lt;T&gt;</code></h3><pre><code><span class=\"where fmt-newline\">impl&lt;T: <a class=\"trait\" href=\"trait.SomeTrait.html\" title=\"trait doc_notable_trait::SomeTrait\">SomeTrait</a>&gt; <a class=\"trait\" href=\"trait.SomeTrait.html\" title=\"trait doc_notable_trait::SomeTrait\">SomeTrait</a> for <a class=\"struct\" href=\"struct.Wrapper.html\" title=\"struct doc_notable_trait::Wrapper\">Wrapper</a>&lt;T&gt;</span>"}</script>
\ No newline at end of file
-<script type="text/json" id="notable-traits-data">{"Wrapper<Self>":"<h3>Notable traits for <code><a class=\"struct\" href=\"struct.Wrapper.html\" title=\"struct doc_notable_trait::Wrapper\">Wrapper</a>&lt;T&gt;</code></h3><pre><code><span class=\"where fmt-newline\">impl&lt;T:&nbsp;<a class=\"trait\" href=\"trait.SomeTrait.html\" title=\"trait doc_notable_trait::SomeTrait\">SomeTrait</a>&gt; <a class=\"trait\" href=\"trait.SomeTrait.html\" title=\"trait doc_notable_trait::SomeTrait\">SomeTrait</a> for <a class=\"struct\" href=\"struct.Wrapper.html\" title=\"struct doc_notable_trait::Wrapper\">Wrapper</a>&lt;T&gt;</span>"}</script>
\ No newline at end of file
+<script type="text/json" id="notable-traits-data">{"Wrapper<Self>":"<h3>Notable traits for <code><a class=\"struct\" href=\"struct.Wrapper.html\" title=\"struct doc_notable_trait::Wrapper\">Wrapper</a>&lt;T&gt;</code></h3><pre><code><span class=\"where fmt-newline\">impl&lt;T: <a class=\"trait\" href=\"trait.SomeTrait.html\" title=\"trait doc_notable_trait::SomeTrait\">SomeTrait</a>&gt; <a class=\"trait\" href=\"trait.SomeTrait.html\" title=\"trait doc_notable_trait::SomeTrait\">SomeTrait</a> for <a class=\"struct\" href=\"struct.Wrapper.html\" title=\"struct doc_notable_trait::Wrapper\">Wrapper</a>&lt;T&gt;</span>"}</script>
\ No newline at end of file
-<pre class="rust item-decl"><code>pub enum Cow2<'a, B:
 ?<a class="trait" href="{{channel}}/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a> + <a class="trait" href="trait.ToOwned.html" title="trait foo::ToOwned">ToOwned</a><dyn <a class="trait" href="{{channel}}/core/clone/trait.Clone.html" title="trait core::clone::Clone">Clone</a>> + 'a> {
+<pre class="rust item-decl"><code>pub enum Cow2<'a, B:
?<a class="trait" href="{{channel}}/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a> + <a class="trait" href="trait.ToOwned.html" title="trait foo::ToOwned">ToOwned</a><dyn <a class="trait" href="{{channel}}/core/clone/trait.Clone.html" title="trait core::clone::Clone">Clone</a>> + 'a> {
Borrowed(<a class="primitive" href="{{channel}}/std/primitive.reference.html">&'a B</a>),
Whatever(<a class="primitive" href="{{channel}}/std/primitive.u32.html">u32</a>),
}</code></pre>
\ No newline at end of file
-<pre class="rust item-decl"><code>pub struct Struct2<'a, B:
 ?<a class="trait" href="{{channel}}/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a> + <a class="trait" href="trait.ToOwned.html" title="trait foo::ToOwned">ToOwned</a><dyn <a class="trait" href="{{channel}}/core/clone/trait.Clone.html" title="trait core::clone::Clone">Clone</a>> + 'a> {
+<pre class="rust item-decl"><code>pub struct Struct2<'a, B:
?<a class="trait" href="{{channel}}/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a> + <a class="trait" href="trait.ToOwned.html" title="trait foo::ToOwned">ToOwned</a><dyn <a class="trait" href="{{channel}}/core/clone/trait.Clone.html" title="trait core::clone::Clone">Clone</a>> + 'a> {
pub a: <a class="primitive" href="{{channel}}/std/primitive.reference.html">&'a B</a>,
pub b: <a class="primitive" href="{{channel}}/std/primitive.u32.html">u32</a>,
}</code></pre>
\ No newline at end of file
-<pre class="rust item-decl"><code>pub union Union2<'a, B:
 ?<a class="trait" href="{{channel}}/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a> + <a class="trait" href="trait.ToOwned.html" title="trait foo::ToOwned">ToOwned</a><dyn <a class="trait" href="{{channel}}/core/clone/trait.Clone.html" title="trait core::clone::Clone">Clone</a>> + 'a> {
+<pre class="rust item-decl"><code>pub union Union2<'a, B:
?<a class="trait" href="{{channel}}/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a> + <a class="trait" href="trait.ToOwned.html" title="trait foo::ToOwned">ToOwned</a><dyn <a class="trait" href="{{channel}}/core/clone/trait.Clone.html" title="trait core::clone::Clone">Clone</a>> + 'a> {
/* private fields */
}</code></pre>
\ No newline at end of file
enum Foo { Bar }
fn foo(x: impl Iterator<Item = Foo>) {
for <Foo>::Bar in x {}
- //~^ ERROR expected one of `const`, `move`, `static`, `|`
+ //~^ ERROR expected one of `move`, `static`, `|`
//~^^ ERROR `for<...>` binders for closures are experimental
}
-error: expected one of `const`, `move`, `static`, `|`, or `||`, found `::`
+error: expected one of `move`, `static`, `|`, or `||`, found `::`
--> $DIR/recover-quantified-closure.rs:9:14
|
LL | for <Foo>::Bar in x {}
- | ^^ expected one of `const`, `move`, `static`, `|`, or `||`
+ | ^^ expected one of `move`, `static`, `|`, or `||`
error[E0658]: `for<...>` binders for closures are experimental
--> $DIR/recover-quantified-closure.rs:2:5
--- /dev/null
+// check-pass
+
+#![feature(const_trait_impl, const_closures)]
+#![allow(incomplete_features)]
+
+const fn test() -> impl ~const Fn() {
+ const move || {}
+}
+
+fn main() {}
--- /dev/null
+// run-rustfix
+
+#![allow(unused)]
+
+struct Wrapper<T>(T);
+
+fn bar() -> Wrapper<fn()> { Wrapper(foo) }
+//~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types
+
+fn foo() {}
+
+fn main() {}
--- /dev/null
+// run-rustfix
+
+#![allow(unused)]
+
+struct Wrapper<T>(T);
+
+fn bar() -> _ { Wrapper(foo) }
+//~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types
+
+fn foo() {}
+
+fn main() {}
--- /dev/null
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
+ --> $DIR/suggest-fn-ptr-for-fn-item-in-fn-ret.rs:7:13
+ |
+LL | fn bar() -> _ { Wrapper(foo) }
+ | ^
+ | |
+ | not allowed in type signatures
+ | help: replace with the correct return type: `Wrapper<fn()>`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0121`.
[autolabel."WG-trait-system-refactor"]
trigger_files = [
- "compiler/rustc_trait_selection/src/solve"
+ "compiler/rustc_trait_selection/src/solve",
+ "compiler/rustc_middle/src/traits/solve.rs"
]
[notify-zulip."I-prioritize"]
[mentions."src/doc/style-guide"]
cc = ["@rust-lang/style"]
+[mentions."Cargo.lock"]
+message = """
+These commits modify the `Cargo.lock` file. Random changes to `Cargo.lock` can be introduced when switching branches and rebasing PRs.
+This was probably unintentional and should be reverted before this PR is merged.
+
+If this was intentional then you can ignore this comment.
+"""
+
[assign]
warn_non_default_branch = true
contributing_url = "https://rustc-dev-guide.rust-lang.org/contributing.html"
projects / rust.git / commitdiff