C++ FAQ Celebrating Twenty-One Years of the C++ FAQ!!!
(Click here for a personal note from Marshall Cline.)
Section 39:
39.1 How do I convert a value (a number, for example) to a std::string?
39.2 How do I convert a std::string to a number?
39.3 Can I templatize the above functions so they work with other types?
39.4 What should be done with macros that contain if?
39.5 What should be done with macros that have multiple lines?
39.6 What should be done with macros that need to paste two tokens together? Updated!
39.7 Why can't the compiler find my header file in #include "c:\test.h" ?
39.8 What are the C++ scoping rules for for loops?
39.9 Why can't I overload a function by its return type?
39.10 What is "persistence"? What is a "persistent object"?
39.11 How can I create two classes that both know about each other?
39.12 What special considerations are needed when forward declarations are used with member objects?
39.13 What special considerations are needed when forward declarations are used with inline functions?
39.14 Why can't I put a forward-declared class in a std::vector<>?
39.15 Why do some people think x = ++y + y++ is bad?
39.16 What's the deal with "sequence points"?
[39.9] Why can't I overload a function by its return type?

If you declare both char f() and float f(), the compiler gives you an error message, since calling simply f() would be ambiguous.