| // Copyright 2012-2014 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. |
| |
| |
| |
| |
| trait to_str { |
| fn to_string_(&self) -> String; |
| } |
| impl to_str for isize { |
| fn to_string_(&self) -> String { self.to_string() } |
| } |
| impl to_str for String { |
| fn to_string_(&self) -> String { self.clone() } |
| } |
| impl to_str for () { |
| fn to_string_(&self) -> String { "()".to_string() } |
| } |
| |
| trait map<T> { |
| fn map<U, F>(&self, f: F) -> Vec<U> where F: FnMut(&T) -> U; |
| } |
| impl<T> map<T> for Vec<T> { |
| fn map<U, F>(&self, mut f: F) -> Vec<U> where F: FnMut(&T) -> U { |
| let mut r = Vec::new(); |
| for i in self { |
| r.push(f(i)); |
| } |
| r |
| } |
| } |
| |
| fn foo<U, T: map<U>>(x: T) -> Vec<String> { |
| x.map(|_e| "hi".to_string() ) |
| } |
| fn bar<U:to_str,T:map<U>>(x: T) -> Vec<String> { |
| x.map(|_e| _e.to_string_() ) |
| } |
| |
| pub fn main() { |
| assert_eq!(foo(vec!(1)), ["hi".to_string()]); |
| assert_eq!(bar::<isize, Vec<isize> >(vec!(4, 5)), ["4".to_string(), "5".to_string()]); |
| assert_eq!(bar::<String, Vec<String> >(vec!("x".to_string(), "y".to_string())), |
| ["x".to_string(), "y".to_string()]); |
| assert_eq!(bar::<(), Vec<()>>(vec!(())), ["()".to_string()]); |
| } |