c++ urlencode能处理空格吗

C++??????urlencode??,???????????????URL????????????,????????????" "??"+"????????????????????:

#include 
#include 

std::string urlencode(const std::string &str) {
    std::ostringstream escaped;
    escaped.fill('0');
    escaped << std::hex;

    for (std::string::const_iterator i = str.begin(), n = str.end(); i != n; ++i) {
        std::string::value_type c = (*i);

        // Keep alphanumeric and other accepted characters intact
        if (isalnum(c) || c == '-' || c == '_' || c == '.' || c == '~') {
            escaped << c;
            continue;
        }

        // Any other characters are percent-encoded
        escaped << std::uppercase;
        escaped << '%' << std::setw(2) << int((unsigned char) c);
        escaped << std::nouppercase;
    }

    return escaped.str();
}

int main() {
    std::string input = "Hello World";
    std::string output = urlencode(input);

    std::cout << "Input: " << input << std::endl;
    std::cout << "URL-encoded: " << output << std::endl;

    return 0;
}

????????urlencode????????????????" "????????????????????????URL?????