#include <iostream>
#include <regex>
 
int main()
{
    std::regex pattern { "a{3}" };
    std::cout << "'a{3}' match with '': " << std::boolalpha << 
        std::regex_match("a", pattern) << std::endl;
        
    std::cout << "'a{3}' match with 'aaaa': " << std::boolalpha << 
        std::regex_match("aaaa", pattern) << std::endl;
        
    std::cout << "'a{3}' match with 'aaaaaaaa': " << std::boolalpha << 
        std::regex_match("aaaaaaaa", pattern) << std::endl << std::endl;
        
    pattern = "a{3,}";
    std::cout << "'a{3,}' match with '': " << std::boolalpha << 
        std::regex_match("a", pattern) << std::endl;
        
    std::cout << "'a{3,}' match with 'aaaa': " << std::boolalpha << 
        std::regex_match("aaaa", pattern) << std::endl;
        
    std::cout << "'a{3,}' match with 'aaaaaaaa': " << std::boolalpha << 
        std::regex_match("aaaaaaaa", pattern) << std::endl << std::endl;
        
    pattern = "a{3,5}";
    std::cout << "'a{3,5}' match with '': " << std::boolalpha << 
        std::regex_match("a", pattern) << std::endl;
        
    std::cout << "'a{3,5}' match with 'aaaa': " << std::boolalpha << 
        std::regex_match("aaaa", pattern) << std::endl;
        
    std::cout << "'a{3,5}' match with 'aaaaaaaa': " << std::boolalpha << 
        std::regex_match("aaaaaaaa", pattern) << std::endl;
}