This commit is contained in:
Nick Cameron 2015-02-09 16:49:27 +13:00
parent 8122ce81d0
commit f9c577e514
4 changed files with 131 additions and 4 deletions

View File

@ -1025,11 +1025,11 @@ impl<'a> State<'a> {
self.print_path(&t.path, false)
}
fn print_poly_trait_ref(&mut self, t: &ast::PolyTraitRef) -> IoResult<()> {
if !t.bound_lifetimes.is_empty() {
fn print_formal_lifetime_list(&mut self, lifetimes: &[ast::LifetimeDef]) -> IoResult<()> {
if !lifetimes.is_empty() {
try!(word(&mut self.s, "for<"));
let mut comma = false;
for lifetime_def in &t.bound_lifetimes {
for lifetime_def in lifetimes {
if comma {
try!(self.word_space(","))
}
@ -1038,7 +1038,11 @@ impl<'a> State<'a> {
}
try!(word(&mut self.s, ">"));
}
Ok(())
}
fn print_poly_trait_ref(&mut self, t: &ast::PolyTraitRef) -> IoResult<()> {
try!(self.print_formal_lifetime_list(&t.bound_lifetimes));
self.print_trait_ref(&t.trait_ref)
}
@ -2517,9 +2521,11 @@ impl<'a> State<'a> {
}
match predicate {
&ast::WherePredicate::BoundPredicate(ast::WhereBoundPredicate{ref bounded_ty,
&ast::WherePredicate::BoundPredicate(ast::WhereBoundPredicate{ref bound_lifetimes,
ref bounded_ty,
ref bounds,
..}) => {
try!(self.print_formal_lifetime_list(bound_lifetimes));
try!(self.print_type(&**bounded_ty));
try!(self.print_bounds(":", bounds));
}

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@ -0,0 +1,33 @@
// Copyright 2015 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.
// Test that we can quantify lifetimes outside a constraint (i.e., including
// the self type) in a where clause. Specifically, test that implementing for a
// specific lifetime is not enough to satisify the `for<'a> ...` constraint, which
// should require *all* lifetimes.
static X: &'static u32 = &42;
trait Bar {
fn bar(&self);
}
impl Bar for &'static u32 {
fn bar(&self) {}
}
fn foo<T>(x: &T)
where for<'a> &'a T: Bar
{}
fn main() {
foo(&X);
//~^ error: `for<'a> Bar` is not implemented
}

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@ -0,0 +1,29 @@
// Copyright 2015 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.
// Test that we can quantify lifetimes outside a constraint (i.e., including
// the self type) in a where clause. Specifically, test that we cannot nest
// quantification in constraints (to be clear, there is no reason this should not
// we're testing we don't crash or do something stupid).
trait Bar<'a> {
fn bar(&self);
}
impl<'a, 'b> Bar<'b> for &'a u32 {
fn bar(&self) {}
}
fn foo<T>(x: &T)
where for<'a> &'a T: for<'b> Bar<'b>
//~^ error: nested quantification of lifetimes
{}
fn main() {}

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@ -0,0 +1,59 @@
// Copyright 2015 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.
// Test that we can quantify lifetimes outside a constraint (i.e., including
// the self type) in a where clause.
static mut COUNT: u32 = 1;
trait Bar<'a> {
fn bar(&self);
}
trait Baz<'a> {
fn baz(&self);
}
impl<'a, 'b> Bar<'b> for &'a u32 {
fn bar(&self) {
unsafe { COUNT *= 2; }
}
}
impl<'a, 'b> Baz<'b> for &'a u32 {
fn baz(&self) {
unsafe { COUNT *= 3; }
}
}
// Test we can use the syntax for HRL including the self type.
fn foo1<T>(x: &T)
where for<'a, 'b> &'a T: Bar<'b>
{
x.bar()
}
// Test we can quantify multiple bounds (i.e., the precedence is sensible).
fn foo2<T>(x: &T)
where for<'a, 'b> &'a T: Bar<'b> + Baz<'b>
{
x.baz();
x.bar()
}
fn main() {
let x = 42u32;
foo1(&x);
foo2(&x);
unsafe {
assert!(COUNT == 12);
}
}