Function assert_infrequent::at_most

pub fn at_most(n: usize)

Asserts that the given function is called at most n times from any given point.

Example 1:

fn main() {
    assert_infrequent::at_most(1); // Ok, first call to at_most
    assert_infrequent::at_most(1); // Ok, first call to at_most at this callsite
    assert_infrequent::at_most(3); // Ok, 1 < 3.

    for _ in 0..5 {
        assert_infrequent::at_most(5); // Ok, only hit 5 times.
    }
}

Example 2:

fn expensive_computation() -> u64 {
    assert_infrequent::at_most(1);
    // ...
}

fn main() {
    for _ in 0..2 {
        let v = expensive_computation(); // Panic!
        // ...
    }
}