Legibilidade com C++14 - get_numeric

numeric.cpp

std::string get_numeric(const std::string &input) 
{
	std::string output;
	std::for_each(begin(input), end(input), [&output](const char c) {
		if( c >= '0' && c <= '9' ) output.push_back(c);
	});
	return output;
}