src/test/run-pass/trait-to-str.rs

   1 // Copyright 2012-2014 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
  13 trait to_str {
  14     fn to_string_(&self) -> String;
  15 }
  16
  17 impl to_str for isize {
  18     fn to_string_(&self) -> String { self.to_string() }
  19 }
  20
  21 impl<T:to_str> to_str for Vec<T> {
  22     fn to_string_(&self) -> String {
  23         format!("[{}]",
  24                 self.iter()
  25                     .map(|e| e.to_string_())
  26                     .collect::<Vec<String>>()
  27                     .connect(", "))
  28     }
  29 }
  30
  31 pub fn main() {
  32     assert!(1.to_string_() == "1".to_string());
  33     assert!((vec!(2, 3, 4)).to_string_() == "[2, 3, 4]".to_string());
  34
  35     fn indirect<T:to_str>(x: T) -> String {
  36         format!("{}!", x.to_string_())
  37     }
  38     assert!(indirect(vec!(10, 20)) == "[10, 20]!".to_string());
  39
  40     fn indirect2<T:to_str>(x: T) -> String {
  41         indirect(x)
  42     }
  43     assert!(indirect2(vec!(1)) == "[1]!".to_string());
  44 }