Function count 

pub fn count<T>(items: &[T]) -> HashMap<T, usize>
where
    T: Hash + Eq + Clone,

统计元素出现次数/Count element occurrences

参数/Arguments

• items - 要统计的数组/The array to count

返回值/Returns

HashMap<T, usize> 键为元素，值为出现次数/Key is element, value is count

示例/Examples

use slice_reducer::count;
let nums = [1, 2, 2, 3];
let counts = count(&nums);
assert_eq!(counts[&2], 2);