Question

I’ve been stumped on my code all day today. I have a number of classes to deal with a collection of tracks and albums.
My code compiles and it reads in the file successfully, but as soon as i try to use the istream& operator in my Album Collection class it errors at run time.

This is the error:

   error LNK2001: unresolved external symbol "class std::basic_istream<char,struct    std::char_traits<char> > & __cdecl operator>>(class std::basic_istream<char,struct std::char_traits<char> > &,class AlbumCollection &)" (??5@YAAAV?$basic_istream@DU?$char_traits@D@std@@@std@@AAV01@AAVAlbumCollection@@@Z)1>C:\Users\Shardy\Desktop\AlbumDatabase\Debug\AlbumDatabase.exe : fatal error LNK1120: 1 unresolved externals

I would really appreciate some help. Its become frustrating. None of my books nor google is shedding any light. Thanks for your time.

Answer 1

Some issues:

1. main.c: If the file is successfully opened, you state that the file
   was loaded successfully. Why bother opening the file in the first
   place if it is already loaded? Hmm, how can that be?
2. main.c: You never call any method that reads from the file.
3. main.c: You can use if (file) instead of if (file.is_open())
4. main.c: You’re missing a closing } in the if statement.
5. main.c: You’re not using argc or argv so you can declare main
   as main(void).
6. You need to post the class declaration (header file) as well as the
   method definitions.
7. duration.cpp: Your input method will gag when it encounters
   something not numeric or whitespace, such as “:”.
8. duration.cpp: Your addition operator doesn’t perform time arithmetic
   correctly, especially overflows. Try adding “00:59:35” with
   “00:02:30”.
9. duration.cpp: Your operator== will return the result of the last
   expression, because you are using the comma, ‘,’ operator. You
   probably want to use the && or logical AND operator.
10. duration.cpp: Rule of 3: If you define a constructor, copy
    constructor or destruction you should declare all 3 and an
    assignment operator.
11. duration.cpp: Rule of Math: If you define operator+ or
    operator- you should also implement operators += and -= as
    well. See Boost math library.
12. duration.cpp: Rule of ordering: If you plan to order or compare,
    you should implement operators <, <=, ==, !=, >, and >=. Hint:
    convert the time into seconds, which should make your life easier
    when comparing. See boost::less_than_comparable.

13. track.cpp: You’re input method reads the track name first, then
    the duration. The data file shows duration first then track name.
    You also have no code to deal with the field separator between
    duration and column.

    Yep, a debugger would be helpful as well as pencil and paper to go through this code.