如何在 C 中有效地将十六进制字符串转换为字节数组？

std::vector<char> HexToBytes(const std::string& hex) {
  std::vector<char> bytes;

  // Loop through the hex string in pairs of characters
  for (unsigned int i = 0; i < hex.length(); i += 2) {
    // Extract the current pair of characters
    std::string byteString = hex.substr(i, 2);

    // Convert the pair to a char using strtol()
    char byte = (char)strtol(byteString.c_str(), NULL, 16);

    // Append the char to the byte array
    bytes.push_back(byte);
  }

  // Return the byte array
  return bytes;
}