prohibit turbofish in impl Trait methods

This commit is contained in:
Niko Matsakis 2018-05-24 17:34:23 -04:00
parent a76bff86e6
commit 558cbfb19b
5 changed files with 75 additions and 31 deletions

View File

@ -46,18 +46,21 @@ pub struct ConfirmResult<'tcx> {
}
impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
pub fn confirm_method(&self,
span: Span,
self_expr: &'gcx hir::Expr,
call_expr: &'gcx hir::Expr,
unadjusted_self_ty: Ty<'tcx>,
pick: probe::Pick<'tcx>,
segment: &hir::PathSegment)
-> ConfirmResult<'tcx> {
debug!("confirm(unadjusted_self_ty={:?}, pick={:?}, generic_args={:?})",
unadjusted_self_ty,
pick,
segment.parameters);
pub fn confirm_method(
&self,
span: Span,
self_expr: &'gcx hir::Expr,
call_expr: &'gcx hir::Expr,
unadjusted_self_ty: Ty<'tcx>,
pick: probe::Pick<'tcx>,
segment: &hir::PathSegment,
) -> ConfirmResult<'tcx> {
debug!(
"confirm(unadjusted_self_ty={:?}, pick={:?}, generic_args={:?})",
unadjusted_self_ty,
pick,
segment.parameters,
);
let mut confirm_cx = ConfirmContext::new(self, span, self_expr, call_expr);
confirm_cx.confirm(unadjusted_self_ty, pick, segment)
@ -78,11 +81,12 @@ impl<'a, 'gcx, 'tcx> ConfirmContext<'a, 'gcx, 'tcx> {
}
}
fn confirm(&mut self,
unadjusted_self_ty: Ty<'tcx>,
pick: probe::Pick<'tcx>,
segment: &hir::PathSegment)
-> ConfirmResult<'tcx> {
fn confirm(
&mut self,
unadjusted_self_ty: Ty<'tcx>,
pick: probe::Pick<'tcx>,
segment: &hir::PathSegment,
) -> ConfirmResult<'tcx> {
// Adjust the self expression the user provided and obtain the adjusted type.
let self_ty = self.adjust_self_ty(unadjusted_self_ty, &pick);
@ -300,17 +304,19 @@ impl<'a, 'gcx, 'tcx> ConfirmContext<'a, 'gcx, 'tcx> {
})
}
fn instantiate_method_substs(&mut self,
pick: &probe::Pick<'tcx>,
segment: &hir::PathSegment,
parent_substs: &Substs<'tcx>)
-> &'tcx Substs<'tcx> {
fn instantiate_method_substs(
&mut self,
pick: &probe::Pick<'tcx>,
segment: &hir::PathSegment,
parent_substs: &Substs<'tcx>,
) -> &'tcx Substs<'tcx> {
// Determine the values for the generic parameters of the method.
// If they were not explicitly supplied, just construct fresh
// variables.
let method_generics = self.tcx.generics_of(pick.item.def_id);
let mut fn_segment = Some((segment, method_generics));
self.fcx.check_path_parameter_count(self.span, &mut fn_segment, true, false);
let supress_mismatch = self.fcx.check_impl_trait(self.span, fn_segment);
self.fcx.check_path_parameter_count(self.span, &mut fn_segment, true, supress_mismatch);
// Create subst for early-bound lifetime parameters, combining
// parameters from the type and those from the method.

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@ -179,12 +179,14 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
self.tcx.check_stability(pick.item.def_id, Some(call_expr.id), span);
let result = self.confirm_method(span,
self_expr,
call_expr,
self_ty,
pick.clone(),
segment);
let result = self.confirm_method(
span,
self_expr,
call_expr,
self_ty,
pick.clone(),
segment,
);
if result.illegal_sized_bound {
// We probe again, taking all traits into account (not only those in scope).

View File

@ -4734,7 +4734,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
// variables. If the user provided some types, we may still need
// to add defaults. If the user provided *too many* types, that's
// a problem.
let supress_mismatch = self.check_impl_trait(span, &mut fn_segment);
let supress_mismatch = self.check_impl_trait(span, fn_segment);
self.check_path_parameter_count(span, &mut type_segment, false, supress_mismatch);
self.check_path_parameter_count(span, &mut fn_segment, false, supress_mismatch);
@ -5019,7 +5019,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
/// Report error if there is an explicit type parameter when using `impl Trait`.
fn check_impl_trait(&self,
span: Span,
segment: &mut Option<(&hir::PathSegment, &ty::Generics)>)
segment: Option<(&hir::PathSegment, &ty::Generics)>)
-> bool {
let segment = segment.map(|(path_segment, generics)| {
let explicit = !path_segment.infer_types;

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@ -0,0 +1,27 @@
// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use std::any::Any;
pub struct EventHandler {
}
impl EventHandler
{
pub fn handle_event<T: Any>(&mut self, _efunc: impl FnMut(T)) {}
}
struct TestEvent(i32);
fn main() {
let mut evt = EventHandler {};
evt.handle_event::<TestEvent, fn(TestEvent)>(|_evt| {
//~^ ERROR cannot provide explicit type parameters
});
}

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@ -0,0 +1,9 @@
error[E0632]: cannot provide explicit type parameters when `impl Trait` is used in argument position.
--> $DIR/universal-turbofish-in-method-issue-50950.rs:24:9
|
LL | evt.handle_event::<TestEvent, fn(TestEvent)>(|_evt| {
| ^^^^^^^^^^^^
error: aborting due to previous error
For more information about this error, try `rustc --explain E0632`.