content: /*
   * Copyright 2021 Alibaba Group Holding Limited.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *  	http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package com.alibaba.graphscope.ds;
  
  import static com.alibaba.graphscope.utils.CppClassName.GRAPE_EMPTY_TYPE;
  import static com.alibaba.graphscope.utils.CppHeaderName.GRAPE_TYPES_H;
  
  import com.alibaba.fastffi.CXXHead;
  import com.alibaba.fastffi.FFIFactory;
  import com.alibaba.fastffi.FFIGen;
  import com.alibaba.fastffi.FFIPointer;
  import com.alibaba.fastffi.FFITypeAlias;
  import com.alibaba.fastffi.FFITypeFactory;
  
  /**
   * Empty type is an type placeholder to put in a template class or template method, it is a wrapper
   * for <a
   * href="https://github.com/alibaba/libgrape-lite/blob/master/grape/types.h">grape::EmptyType</a>.
   */
  @FFIGen
  @CXXHead(GRAPE_TYPES_H)
  @FFITypeAlias(GRAPE_EMPTY_TYPE)
  public interface EmptyType extends FFIPointer {
      Factory factory = FFITypeFactory.getFactory(Factory.class, EmptyType.class);
  
      /** Factor for EmptyType. */
      @FFIFactory
      interface Factory {
  
          /**
           * Create a new instance.
           *
           * @return a new instance.
           */
          EmptyType create();
      }
  }
  