Function transform

webrtc/base/stringencode.cc:540–546

}

size_t transform(std::string& value, size_t maxlen, const std::string& source,
                 Transform t) {
  char* buffer = STACK_ARRAY(char, maxlen + 1);
  size_t length = t(buffer, maxlen + 1, source.data(), source.length());
  value.assign(buffer, length);
  return length;
}

std::string s_transform(const std::string& source, Transform t) {
  // Ask transformation function to approximate the destination size (returns upper bound)