date_validation_regex.cpp

// Validate date using regex
// Format: YYYY/MM/DD

#include <iostream>
#include <regex>

bool isDateValid( const std::string& date )
{
    std::regex  regexDate { R"(\d{4}/\d{2}/\d{2})" };
    std::smatch match;
    std::regex_match( date, match, regexDate );
    std::cout << match.str() << std::endl;
    return !match.str().empty();
}

int main()
{
	const std::string date { "2016/12/17" };
	std::cout << std::boolalpha << isDateValid( date ) << std::endl;
	return 0;
}