MultiThreadAllSubStrings

moodycamel::ConcurrentQueue<std::wstring> worker_queue;
std::wstring ascii = L"abcdefghijklmnopqrstuvwxyz._-0123456789";

void handle_comb()
{
    while (true) {
        std::wstring attempt;
        if (!worker_queue.try_dequeue(attempt)) {
            continue;
        }
    
        ... do stuff ...
    }
}

void add_work_item(const std::wstring& item)
{
	bool queued = false;
	do { 
		queued = worker_queue.try_enqueue(item);
	} while(!queued);
}

int main()
{
	std::vector<std::thread> threads;
	for (int i = 0; i < 14; i++) {
		threads.push_back(std::thread(handle_comb));
	}

	for (int i = 0; i < 16; i++) {
		for (auto&& i : iter::combinations_with_replacement(ascii, i)) {
			for (auto&& j : iter::permutations(i)) {
				std::wstring attempt;
				attempt.reserve(j.size());
				for (auto c : j) {
					attempt.push_back(c);
				}
				add_work_item(attempt);
			}
		}
	}
	
	for (auto& thread : threads) {
		thread.join();
	}
}