Can somebody please explain the reason for paragraph 12 in section 5.2.2 of
the April 95 working paper:

 A function call is an lvalue if and only if the result type is a reference.

Please note, that functions returning class objects have to return something
very similar to a lvalue, you can call even non-constant member functions
on this type of 'rvalues', you can also easily convert them to an lvalue:

 class foo{
  ....
  foo & lvalue(){return *this;};
 }

 foo f(void);

Now
 f().lvalue()

obviously converts the rvalue generated by f() to an lvalue.

So why not simply change the mentioned paragraph to

 A function call is an lvalue if and only if the result is a
 reference or a non-const class type.

( lvalue: foo f(); rvalue: const foo f();)

or, if you don't like that idea because it would also change overload
resolution and might therefore break existing code, introduce a new
meaning of the keyword 'mutable':

 A function call is an lvalue if and only if the result is a
 reference or a mutable class type.

(lvalue: mutable foo f(); rvalue: foo f();)

This would also solve the auto_ptr problem.

--
Bernd Anhaeupl   Tel.:  +49 9131 857787
LATE - Uni Erlangen
Cauerstr. 7   Email: anhaeupl@late.e-technik.uni-erlangen.de
91058 Erlangen
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