/// parameter environment.
#[derive(PartialEq,Eq,Debug,Clone)]
enum SelectionCandidate<'tcx> {
+ /// If has_nested is false, there are no *further* obligations
BuiltinCandidate { has_nested: bool },
ParamCandidate(ty::PolyTraitRef<'tcx>),
ImplCandidate(DefId),
}
match other.candidate {
+ // Prefer BuiltinCandidate { has_nested: false } to anything else.
+ // This is a fix for #53123 and prevents winnowing from accidentally extending the
+ // lifetime of a variable.
+ BuiltinCandidate { has_nested: false } => true,
ParamCandidate(ref cand) => match victim.candidate {
AutoImplCandidate(..) => {
bug!(
"default implementations shouldn't be recorded \
when there are other valid candidates");
}
+ // Prefer BuiltinCandidate { has_nested: false } to anything else.
+ // This is a fix for #53123 and prevents winnowing from accidentally extending the
+ // lifetime of a variable.
+ BuiltinCandidate { has_nested: false } => false,
ImplCandidate(..) |
ClosureCandidate |
GeneratorCandidate |
"default implementations shouldn't be recorded \
when there are other valid candidates");
}
+ // Prefer BuiltinCandidate { has_nested: false } to anything else.
+ // This is a fix for #53123 and prevents winnowing from accidentally extending the
+ // lifetime of a variable.
+ BuiltinCandidate { has_nested: false } => false,
ImplCandidate(..) |
ClosureCandidate |
GeneratorCandidate |
FnPointerCandidate |
BuiltinObjectCandidate |
BuiltinUnsizeCandidate |
- BuiltinCandidate { .. } => {
+ BuiltinCandidate { has_nested: true } => {
match victim.candidate {
ParamCandidate(ref cand) => {
// Prefer these to a global where-clause bound
--- /dev/null
+// 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.
+
+#![feature(nll)]
+#![allow(unused_variables)]
+
+pub trait TryTransform {
+ fn try_transform<F>(self, f: F)
+ where
+ Self: Sized,
+ F: FnOnce(Self);
+}
+
+impl<'a, T> TryTransform for &'a mut T {
+ fn try_transform<F>(self, f: F)
+ where
+ // The bug was that `Self: Sized` caused the lifetime of `this` to "extend" for all
+ // of 'a instead of only lasting as long as the binding is used (for just that line).
+ Self: Sized,
+ F: FnOnce(Self),
+ {
+ let this: *mut T = self as *mut T;
+ f(self);
+ }
+}
+
+fn main() {
+}