{"id":3513,"date":"2011-01-28T00:44:08","date_gmt":"2011-01-28T00:44:08","guid":{"rendered":"https:\/\/blogs.msdn.microsoft.com\/vcblog\/2011\/01\/28\/heritage-shared\/"},"modified":"2021-10-06T10:50:10","modified_gmt":"2021-10-06T10:50:10","slug":"heritage-shared","status":"publish","type":"post","link":"https:\/\/devblogs.microsoft.com\/cppblog\/heritage-shared\/","title":{"rendered":"Heritage Shared"},"content":{"rendered":"

A few days ago, we posted two C++ quizzes<\/a> based on a question posted in a forum. Let\u2019s review the first question<\/p>\n

 <\/p>\n

\n
\n
Quiz 1<\/div>\n
\n
    \n
  1. #include<\/span> <iostream><\/span><\/li>\n
  2. <\/li>\n
  3. class<\/span> Foo {<\/li>\n
  4. public<\/span>:<\/li>\n
  5. \u00a0\u00a0\u00a0\u00a0virtual<\/span> void<\/span> DoStuff()=0;<\/li>\n
  6. };<\/li>\n
  7. <\/li>\n
  8. class<\/span> Bar : public<\/span> Foo {<\/li>\n
  9. public<\/span>:<\/li>\n
  10. \u00a0\u00a0\u00a0\u00a0virtual<\/span> void<\/span> DoStuff(int<\/span> a)=0;<\/li>\n
  11. };<\/li>\n
  12. <\/li>\n
  13. class<\/span> Baz : public<\/span> Bar {<\/li>\n
  14. public<\/span>:<\/li>\n
  15. \u00a0\u00a0\u00a0\u00a0void<\/span> DoStuff(int<\/span> a) override<\/span><\/li>\n
  16. \u00a0\u00a0\u00a0\u00a0{<\/li>\n
  17. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0std::cout << “Baz::DoStuff(int)”<\/span>;<\/li>\n
  18. \u00a0\u00a0\u00a0\u00a0}<\/li>\n
  19. <\/li>\n
  20. \u00a0\u00a0\u00a0\u00a0void<\/span> DoStuff() override<\/span><\/li>\n
  21. \u00a0\u00a0\u00a0\u00a0{<\/li>\n
  22. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0std::cout << “Baz::DoStuff()”<\/span>;<\/li>\n
  23. \u00a0\u00a0\u00a0\u00a0}<\/li>\n
  24. };<\/li>\n
  25. <\/li>\n
  26. int<\/span> main() {<\/li>\n
  27. \u00a0\u00a0\u00a0\u00a0Baz baz;<\/li>\n
  28. \u00a0\u00a0\u00a0\u00a0Bar *pBar = &baz;<\/li>\n
  29. <\/li>\n
  30. \u00a0\u00a0\u00a0\u00a0pBar->DoStuff();<\/li>\n
  31. }<\/li>\n<\/ol>\n<\/div>\n<\/div>\n<\/div>\n

     <\/p>\n

    The guy was frustrated because he expected two things:<\/p>\n