Function rufl::collection::count_by

pub fn count_by<C: AsRef<[T]>, T>(
    collection: C,
    predicate: impl Fn(&T, usize) -> bool
) -> usize

Iterates over elements of collection with predicate function, returns the number of all matched elements.

• predicate function signature: fn(item: &T, index: usize) -> bool

Arguments

• collection - The collection to iterate over.

• predicate - The check function invoked per iteration.

Returns

Returns the number of all elements which pass the predicate check.

Examples

use rufl::collection;

assert_eq!(2, collection::count_by([1, 2, 3, 4, 5], &|n: &i32, _i: usize| *n < 3));

assert_eq!(3, collection::count_by([1, 2, 3, 4, 5].to_vec(), &|n: &i32, _i: usize| *n % 2 != 0));