src/test/auxiliary/specialization_cross_crate_defaults.rs

   1 // Copyright 2015 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11
  12 #![feature(specialization)]
  13
  14 // First, test only use of explicit `default` items:
  15
  16 pub trait Foo {
  17     fn foo(&self) -> bool;
  18 }
  19
  20 impl<T> Foo for T {
  21     default fn foo(&self) -> bool { false }
  22 }
  23
  24 impl Foo for i32 {}
  25
  26 impl Foo for i64 {
  27     fn foo(&self) -> bool { true }
  28 }
  29
  30 // Next, test mixture of explicit `default` and provided methods:
  31
  32 pub trait Bar {
  33     fn bar(&self) -> i32 { 0 }
  34 }
  35
  36 impl<T> Bar for T {} // use the provided method
  37
  38 impl Bar for i32 {
  39     fn bar(&self) -> i32 { 1 }
  40 }
  41 impl<'a> Bar for &'a str {}
  42
  43 impl<T> Bar for Vec<T> {
  44     default fn bar(&self) -> i32 { 2 }
  45 }
  46 impl Bar for Vec<i32> {}
  47 impl Bar for Vec<i64> {
  48     fn bar(&self) -> i32 { 3 }
  49 }