main.rs

extern crate multimap;

use std::hash::Hash;
use multimap::MultiMap;


fn main() {
    let mut mmap = MultiMap::new();
    mmap.insert(1, 'a');
    mmap.insert(1, 'a');
    mmap.insert(1, 'a');
    mmap.insert(1, 'a');
    let vec = vec!['a', 'b', 'c'];
    let iter = vec.iter();

    mmap.insert_many(2, iter);

    println!("{:?}", vec);

    println!("{:?}", mmap)
}

trait InsertMany<K, V> {
    fn insert_many<I: Iterator<Item=V>>(&mut self, k: K, i: I);
}

impl<K, V> InsertMany<K, V> for MultiMap<K, V> where K: Eq + Hash + Copy {
    fn insert_many<I: Iterator<Item=V>>(&mut self, k: K, it: I) {
        for value in it {
            self.insert(k, value);
        }
    }
}

error[E0271]: type mismatch resolving `<std::slice::Iter<'_, char> as std::iter::Iterator>::Item == char`
  --> src\main.rs:16:10
   |
16 |     mmap.insert_many(2, iter);
   |          ^^^^^^^^^^^ expected reference, found char
   |
   = note: expected type `&char`
              found type `char`

error: aborting due to previous error