| // Copyright 2014 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 use method notation to call methods based on a |
| // projection bound from a trait. Issue #20469. |
| |
| /////////////////////////////////////////////////////////////////////////// |
| |
| |
| trait MakeString { |
| fn make_string(&self) -> String; |
| } |
| |
| impl MakeString for isize { |
| fn make_string(&self) -> String { |
| format!("{}", *self) |
| } |
| } |
| |
| impl MakeString for usize { |
| fn make_string(&self) -> String { |
| format!("{}", *self) |
| } |
| } |
| |
| /////////////////////////////////////////////////////////////////////////// |
| |
| trait Foo { |
| type F: MakeString; |
| |
| fn get(&self) -> &Self::F; |
| } |
| |
| fn foo<F:Foo>(f: &F) -> String { |
| f.get().make_string() |
| } |
| |
| /////////////////////////////////////////////////////////////////////////// |
| |
| struct SomeStruct { |
| field: isize, |
| } |
| |
| impl Foo for SomeStruct { |
| type F = isize; |
| |
| fn get(&self) -> &isize { |
| &self.field |
| } |
| } |
| |
| /////////////////////////////////////////////////////////////////////////// |
| |
| struct SomeOtherStruct { |
| field: usize, |
| } |
| |
| impl Foo for SomeOtherStruct { |
| type F = usize; |
| |
| fn get(&self) -> &usize { |
| &self.field |
| } |
| } |
| |
| fn main() { |
| let x = SomeStruct { field: 22 }; |
| assert_eq!(foo(&x), format!("22")); |
| |
| let x = SomeOtherStruct { field: 44 }; |
| assert_eq!(foo(&x), format!("44")); |
| } |