src/test/run-pass/nll/process_or_insert_default.rs

   1 // Copyright 2016 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 // run-pass
  12
  13 #![feature(nll)]
  14
  15 use std::collections::HashMap;
  16
  17 fn process_or_insert_default(map: &mut HashMap<usize, String>, key: usize) {
  18     match map.get_mut(&key) {
  19         Some(value) => {
  20             process(value);
  21         }
  22         None => {
  23             map.insert(key, "".to_string());
  24         }
  25     }
  26 }
  27
  28 fn process(x: &str) {
  29     assert_eq!(x, "Hello, world");
  30 }
  31
  32 fn main() {
  33     let map = &mut HashMap::new();
  34     map.insert(22, format!("Hello, world"));
  35     map.insert(44, format!("Goodbye, world"));
  36     process_or_insert_default(map, 22);
  37     process_or_insert_default(map, 66);
  38     assert_eq!(map[&66], "");
  39 }