void JsonAssign(json &dest, const json &src) {
#ifdef TINYGLTF_USE_RAPIDJSON
  dest.CopyFrom(src, GetAllocator());
#else
  dest = src;
#endif
}
void JsonAssign(json &dest, const json &src) {
#ifdef TINYGLTF_USE_RAPIDJSON
  dest.CopyFrom(src, GetAllocator());
#else
  dest = src;
#endif
}