Instead of bool is_digit = std::regex_match("123", std::regex("\\d+")); you could write leaner: bool is_digit = "\\d+"_re("123"); Isn't this the whole p

Instead of bool is_digit = std::regex_match("123", std::regex("\\d+")); you could write leaner: bool is_digit = "\\d+"_re("123"); Isn't this the whole point of user string literals? Looks like, someone should propose this as a boost library gem.