How to convert hex color string to RGB using regex in C++

  c++, hex, regex

How to convert the hex color string to RGB using regex?

I am using the regex but it is not working. I am not familiar with regex. Is it the correct way?

Below is the sample code:

int main()
    std::string l_strHexValue = "#FF0000";

    std::regex pattern("#?([0-9a-fA-F]{2}){3}");

    std::smatch match;
    if (std::regex_match(l_strHexValue, match, pattern))
        auto r = (uint8_t)std::stoi(match[1].str(), nullptr, 16);
        auto g = (uint8_t)std::stoi(match[2].str(), nullptr, 16);
        auto b = (uint8_t)std::stoi(match[3].str(), nullptr, 16);

    return 0;

Source: Windows Questions C++