Yet another primes streamer.

Primes3.cpp

#include <iostream>
#include <deque>

// This code requires -std=c++11 or better because lambda.

int main() {
	std::deque<unsigned> primes;
	std::deque< std::deque<unsigned> > factors( 3 );
	unsigned a_prime = 3, a_square_prime = 9, maybe_prime = 3;
	std::cout << "2 3";
	
	auto my_insert = [&]( unsigned factor ) {
		if( factor >= factors.size() ) factors.resize( factor+1 );
		factors[factor].emplace_back( factor );
	};

	while( maybe_prime <= 9999 ) {
		const auto &f = factors.front();
		maybe_prime += 2;
		if( !f.empty() ) {
			for( auto ff = f.rbegin(); ff != f.rend(); ++ff )
				my_insert( *ff );
		} else if( maybe_prime < a_square_prime ) {
			std::cout << " " << maybe_prime;
			primes.emplace_back( maybe_prime );
		} else {
			my_insert( a_prime );
			std::swap( a_prime, primes.front() );
			primes.pop_front();
			a_square_prime = a_prime * a_prime;
		}
		factors.pop_front();
	}

	std::cout << std::endl;
	return 0;
}

Run it here: http://cpp.sh/93jux
This prime number generator is in the Sieve of Eratosthenes family.
Unlike common SoE implementations, there is no predefined upper limit -- you could replace the while test with a while(1) and it would run forever.
See https://en.wikipedia.org/wiki/Sieve_of_Eratosthenes#Incremental_sieve