Function sfcpl::binary_search::lower_bound

pub fn lower_bound<T: PartialOrd>(v: &[T], val: &T) -> usize

v以上の要素が最初に現れるindex

use prcn_lib::binary_search::lower_bound;

let v: &[i32] = &[1, 3, 3, 4, 5];
assert_eq!(lower_bound(v, &0), 0);
assert_eq!(lower_bound(v, &1), 0);
assert_eq!(lower_bound(v, &2), 1);
assert_eq!(lower_bound(v, &3), 1);
assert_eq!(lower_bound(v, &4), 3);
assert_eq!(lower_bound(v, &5), 4);
assert_eq!(lower_bound(v, &999), 5);