C++程序  |  53行  |  1.14 KB

/*
 * Copyright (C) 2010 The Android Open Source Project
 *
 * 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.
 */
#include <cstdio>

class Foo
{
public:
  virtual ~Foo() { }
  virtual void print()
  {
    std::printf("in Foo!\n");
  }
};

class Bar: public Foo
{
  public:
  void print()
  {
    std::printf("in Bar!\n");
  }
};

int main()
{
    Foo* foo = new Bar();
    Bar* bar;

    bar = dynamic_cast<Bar*>(foo);
    if (bar != NULL) {
        printf("OK: 'foo' is pointing to a Bar class instance.\n");
    } else {
        fprintf(stderr, "KO: Could not dynamically cast 'foo' to a 'Bar*'\n");
        return 1;
    }

    delete foo;
    return 0;
}