Example does appear to work/parse? #14

Trying: 0 15 10 L * ?
terminate called after throwing an instance of 'cron::bad_cronexpr'
  what():  stoul
Aborted (core dumped)

#include "croncpp.h"

#include <chrono>
#include <iostream>
#include <string>

int main(int argc, char** argv) {
    std::string c = argv[1];
    std::cout << "Trying: "<< c << "\n";
    auto cexpr = cron::make_cron(c);
    auto now = std::chrono::system_clock::to_time_t(std::chrono::system_clock::now());
    auto next = cron::cron_next(cexpr, now);
    std::cout << next << "\n";
    return 0;
}