Function count_primes 

pub fn count_primes(x: u64) -> u64

Counts how many prime numbers are there less than or equal to x

This function is an abstraction for generating prime numbers up to x, then calling the count primes method.

If you only need an approximation, see estimates.

Examples

use prime_data::count_primes;
assert_eq!(count_primes(1_000),   168);
assert_eq!(count_primes(100_000), 9592);