TITLE: return type of operator ->

(Newsgroups: comp.lang.c++.moderated, 5 Oct 98)


HELCK: C Helck <C>

|>> Why does the following produce an error? (Solaris & MS compilers)
|>>
|>> class X { int* p; int* operator->() {return p;} };


OLIVA: Alexandre Oliva <oliva@dcc.unicamp.br>

|>  Because the compilers are wrong.  operator-> needs not return a
|>  pointer to a class type.  In fact, it does not have to return a
|>  pointer.  However, in order to be able to write:
|>  
|>    x->foo;
|>  
|>  given that x is an instance of X, then operator-> must return a
|>  pointer to a class type that has a member named foo, that is not a
|>  member function.
|>  
|>  If operator-> returns anything other than a pointer to class type,
|>  then the only way you can use it is by writing:
|>  
|>    x.operator->();


KANZE: kanze@gabi-soft.fr (J. Kanze)

Note that this is a recent clarification.  Some compilers may still
implement the earlier rule, in which operator-> was required to return
either a pointer to a class or a union, or a class type or a reference
to a class type which overloaded operator->.