src/test/run-pass/issue-14919.rs

   1 // Copyright 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 #![allow(unknown_features)]
  12 #![feature(box_syntax)]
  13
  14 trait Matcher {
  15     fn next_match(&mut self) -> Option<(uint, uint)>;
  16 }
  17
  18 struct CharPredMatcher<'a, 'b> {
  19     str: &'a str,
  20     pred: Box<FnMut(char) -> bool + 'b>,
  21 }
  22
  23 impl<'a, 'b> Matcher for CharPredMatcher<'a, 'b> {
  24     fn next_match(&mut self) -> Option<(uint, uint)> {
  25         None
  26     }
  27 }
  28
  29 trait IntoMatcher<'a, T> {
  30     fn into_matcher(self, &'a str) -> T;
  31 }
  32
  33 impl<'a, 'b, F> IntoMatcher<'a, CharPredMatcher<'a, 'b>> for F where F: FnMut(char) -> bool + 'b {
  34     fn into_matcher(self, s: &'a str) -> CharPredMatcher<'a, 'b> {
  35         CharPredMatcher {
  36             str: s,
  37             pred: box self,
  38         }
  39     }
  40 }
  41
  42 struct MatchIndices<M> {
  43     matcher: M
  44 }
  45
  46 impl<M: Matcher> Iterator for MatchIndices<M> {
  47     type Item = (uint, uint);
  48
  49     fn next(&mut self) -> Option<(uint, uint)> {
  50         self.matcher.next_match()
  51     }
  52 }
  53
  54 fn match_indices<'a, M, T: IntoMatcher<'a, M>>(s: &'a str, from: T) -> MatchIndices<M> {
  55     let string_matcher = from.into_matcher(s);
  56     MatchIndices { matcher: string_matcher }
  57 }
  58
  59 fn main() {
  60     let s = "abcbdef";
  61     match_indices(s, |c: char| c == 'b')
  62         .collect::<Vec<(uint, uint)>>();
  63 }