src/test/ui/traits/trait-to-str.rs

   1 // run-pass
   2 #![allow(non_camel_case_types)]
   3
   4
   5 trait to_str {
   6     fn to_string_(&self) -> String;
   7 }
   8
   9 impl to_str for isize {
  10     fn to_string_(&self) -> String { self.to_string() }
  11 }
  12
  13 impl<T:to_str> to_str for Vec<T> {
  14     fn to_string_(&self) -> String {
  15         format!("[{}]",
  16                 self.iter()
  17                     .map(|e| e.to_string_())
  18                     .collect::<Vec<String>>()
  19                     .join(", "))
  20     }
  21 }
  22
  23 pub fn main() {
  24     assert_eq!(1.to_string_(), "1".to_string());
  25     assert_eq!((vec![2, 3, 4]).to_string_(), "[2, 3, 4]".to_string());
  26
  27     fn indirect<T:to_str>(x: T) -> String {
  28         format!("{}!", x.to_string_())
  29     }
  30     assert_eq!(indirect(vec![10, 20]), "[10, 20]!".to_string());
  31
  32     fn indirect2<T:to_str>(x: T) -> String {
  33         indirect(x)
  34     }
  35     assert_eq!(indirect2(vec![1]), "[1]!".to_string());
  36 }