Function binary_search 

pub fn binary_search<T>(arr: &[T], target: &T) -> Option<usize>
where
    T: Ord,

二分查找/Binary search (要求数组已排序/Array must be sorted)

参数/Arguments

• arr - 已排序的数组/Sorted array to search
• target - 要查找的目标/Target to find

返回值/Returns

目标索引（如果找到）/Index of target if found

示例/Examples

use slice_reducer::binary_search;
let arr = [10, 20, 30, 40];
assert_eq!(binary_search(&arr, &20), Some(1));
assert_eq!(binary_search(&arr, &25), None);