[ forwarded to C++ Committee. -sdc ]

In section 8.5.3 [dcl.init.ref], paragraph 5, there is following note:
>>>>> citation of existing wording of note
Note: the usual lvalue-to-rvalue (4.1), array-to-pointer (4.2), and
function-to-pointer (4.3) standard conversions are not needed, and
therefore are suppressed, when such direct bindings to lvalues are done.
>>>>> end

I believe that this note is misleading. There should be either:
- no note, and leave this issue to be explained in section 4 only
- explicit list of all suppressed conversions (including pointer
qualification conversion, as covered in section 4.4)
- reminder that result of all standard conversions is never an lvalue,
thus these conversions are suppressed when binding reference to lvalue

The problem:

1. under current wording it's unclear if following code is legal, or
not:

int main()
{
  const int ci = 10;
  int * pi = NULL;
  const int * & rpci = pi;
  rpci = &ci;
  *pi = 12; // circumvent constness of "ci"
}

2. it is also unclear what behaviour should following program expose:

int main()
{
  int * pi = NULL;
  const int * const & rcpci = pi; // 1
  int i = 0;
  pi = &i; // 2
  if (pi == rcpci)
    std::cout << "bound to lvalue" << std::endl;
  else
    std::cout << "bound to temporary rvalue" << std::endl;
}

There has been discussion on this issue on comp.lang.c++.moderated month
ago, see
http://groups.google.pl/groups?threadm=9bed99bb.0308041153.1c79e882%40posting.google.com
and there seems to be some confusion about it. I understand that note is
not normative, but apparently even some compiler writers are misled (try
above code snippets on few different compilers, and using different
compilation options - notably GCC 3.2.3 with -Wall -pedantic), thus it
should be cleared up.

My proposal is to change wording of discussed note to:
>>>>> proposed new wording of note
Note: result of every standard conversion is never an lvalue, and
therefore all standard conversions (clause 4) are suppressed, when such
direct bindings to lvalues are done.
>>>>> end

Kind regards


B.Kozicki



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