loggers-mock

main.cpp

#include <fstream>
#include <algorithm>
#include <iostream>
#include <iterator>
#include <string>
#include <vector>

enum class loglevel {
	debug, note, warn, error
};


struct log_target {
	log_target(std::ostream& stream, loglevel min_level = loglevel::note):
		stream{&stream}, min_level{min_level} {}
	log_target(std::ofstream& stream, loglevel min_level = loglevel::note):
		stream{&stream}, min_level{min_level} {
		if(!stream.is_open()) {
			throw std::runtime_error{"logfile not open"};
		}
	}
	std::ostream* stream;
	loglevel min_level;
};

class logger_set {
public:
	logger_set(std::initializer_list<log_target> lst): m_loggers{lst} {}

	void log(loglevel level, const std::string& msg) {
		for(auto& logger: m_loggers) {
			if(level >= logger.min_level) {
				*logger.stream << msg << std::flush;
			}
		}
	}
private:
	std::vector<log_target> m_loggers;
};

int main() {
	auto loggers1 = logger_set{{std::cout}};
	loggers1.log(loglevel::note, "foobar\n");
	std::ofstream file1{"testfile1"};
	auto loggers2 = logger_set{std::cout, {file1, loglevel::error}};
	loggers2.log(loglevel::warn, "blablub\n");
	loggers2.log(loglevel::error, "Some Error\n");
}