-
Notifications
You must be signed in to change notification settings - Fork 12.1k
/
projection.rs
49 lines (37 loc) · 1.03 KB
/
projection.rs
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
// 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.
#![feature(specialization)]
// Make sure we *can* project non-defaulted associated types
// cf compile-fail/specialization-default-projection.rs
// First, do so without any use of specialization
trait Foo {
type Assoc;
}
impl<T> Foo for T {
type Assoc = ();
}
fn generic_foo<T>() -> <T as Foo>::Assoc {
()
}
// Next, allow for one layer of specialization
trait Bar {
type Assoc;
}
default impl<T> Bar for T {
type Assoc = ();
}
impl<T: Clone> Bar for T {
type Assoc = u8;
}
fn generic_bar_clone<T: Clone>() -> <T as Bar>::Assoc {
0u8
}
fn main() {
}