Method groupedIntToString

src/helper.cpp:109–126

create a grouped string from the number `num` s is managed by the calling code, we assume there are `max_len` bytes available 123 => 123 123 => 321 => 1234 => 1,234 12345 => 12,345 123456 => 123,456 1234567 => 1,234,567 */

	1234567 => 1,234,567
*/
std::string Helper::groupedIntToString( int num, std::string sep ) {
	// Caution: Only works for pure 7bit-ASCII text!
	std::string ret = "";
	std::string num_sign = "";
	if( num < 0 ) {
		num_sign = "-";
		num = -num;
	}
	std::string num_str = std::to_string(num);
	std::reverse(num_str.begin(), num_str.end());
	for( size_t i = 0; i < num_str.length(); ++i ) {
		ret.insert(0, 1, num_str[i]);
		if( i % 3 == 2 && i > 0 && i < num_str.length() - 1 ) {
			ret.insert(0, sep);
		}
	}
	return num_sign + ret;
}