Chapter 37. Forward Declarations
Difficulty: 3
Forward declarations are a great way to eliminate needless compile-time dependencies. But here's an example of a forward-declaration snare. How would you avoid it?
Forward declarations are very useful tools. In this case, they don't work as the programmer expected. Why are the marked lines errors?
// file f.h // class ostream; // error class string; // error string f( const ostream& );
Without including any other files, write the correct forward declarations for
ostream
andstring
above.
Solution
1. Forward declarations are very useful tools. In this case, they don't work as the programmer expected. Why ...
Get More Exceptional C++ now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.