logger.d

ILogger {
	void log(string msg);
}

class BoringLogger : ILogger {
	overrride void log(string msg) {...}
}

class ColorfulLogger : ILogger {
	overrride void log(string msg) {...}
}

void writef(T...)(ILogger logger, T params) {
	// all generic code of turning different types of params to string
	// then pass this string to logger
}


main() {
	auto logger1 = new BoringLogger;
	auto logger2 = new ColorfulLogger;

	logger1.writef(1, "hi", 3.3);
	logger2.writef(1, "hi", 3.3);
}