primesieve  5.6.0
previous_prime.cpp

This example shows how to iterate backwards over primes.

#include <primesieve.hpp>
#include <iostream>
int main()
{
pi.skipto(2000);
uint64_t prime;
// iterate backwards over the primes between 2000 and 1000
while ((prime = pi.previous_prime()) >= 1000)
std::cout << prime << std::endl;
return 0;
}