twofsonet@graffiti.com (Andrew Brown) writes:
> an "assignment" usually yields an rvalue (unless you write a c++ class
> that returns a non-const reference from operator=(), which is yet
> another way to make your code confusing :), ie:

The 2 December 1996 Working Paper for the C++ standard (the last
public review draft) section 5.17 [expr.ass] says:

1 There are several assignment operators, all of which  group  right-to-
  left.   All require a modifiable lvalue as their left operand, and the
  type of an assignment expression is that of  its  left  operand.   The
  result  of  the  assignment  operation is the value stored in the left
  operand after the assignment has taken place; the result is an lvalue.
                                                ^^^^^^^^^^^^^^^^^^^^^^^

Since the (draft) standard explicitly specifies that the result of the
assignment operator is an lvalue, not only is your example legal, so
is

   (foo=3) = 5;

and according to the standard, so is

   (foo == 0 ? bar : baz) = 5;

I imagine there is some terribly good reason for all this, but you'd
have to ask on comp.std.c++ to find out what it is.
-- 
Dan Riley                                         dsr@mail.lns.cornell.edu
Wilson Lab, Cornell University      <URL:http://www.lns.cornell.edu/~dsr/>
    "History teaches us that days like this are best spent in bed"