message: use return value optimization
diff: @@ -48,13 +48,11 @@ class ParameterServer {
  static std::unique_ptr<ParameterServerDelegate<TypeHashKey>> get_parameter_server_delegate_(
  const Embedding_t embedding_type) {
  if (embedding_type == Embedding_t::DistributedSlotSparseEmbeddingHash) {
  - std::unique_ptr<ParameterServerDelegate<TypeHashKey>> ptr_tmp(
  + return std::unique_ptr<ParameterServerDelegate<TypeHashKey>>(
  new DistributedParameterServerDelegate<TypeHashKey>());
  - return ptr_tmp;
  } else {
  - std::unique_ptr<ParameterServerDelegate<TypeHashKey>> ptr_tmp(
  + return std::unique_ptr<ParameterServerDelegate<TypeHashKey>>(
  new LocalizedParameterServerDelegate<TypeHashKey>());
  - return ptr_tmp;
  }
  }
  