Re: [boost] [result_of] Test fails on clang trunk and gcc-4.7 due to changes in FDIS

Subject: Re: [boost] [result_of] Test fails on clang trunk and gcc-4.7 due to changes in FDIS
From: Michel Morin (mimomorin_at_[hidden])
Date: 2012-03-28 17:58:12

Eric Niebler wrote:
>> Hmm…, my N3290 does not have such a wording in 7.1.6.2 (dcl.type.simple) p4.
>
> The (non-normative) note in 7.1.6.2 about this is in p5, not p4. But the
> normative text is in 5.2.2 p11.

I don't see any text about about how decltype of a function call expression
is determined in 5.2.2 p11 or 7.1.6.2 p5.

Sorry, my post may be misleading and not clear.
The subject of this thread should be:
    "Test fails on clang trunk and gcc-4.7 due to changes *made* in FDIS"
and I'm talking about the changes *made* in FDIS.

Specifically, the change is about how decltype of a function call expression
is determined.
* N3242 says that in 7.1.6.2 p4:
   if e is a function call or an invocation of an overloaded operator
   (parentheses around e are ignored), decltype(e) is the return type
   of the statically chosen function;

* N3290 (FDIS) does not have such a wording. For a function call expression,
decltype(e) is determined by the last rule in 7.1.6.2 p4:
    otherwise, decltype(e) is the type of e.

So, for "const int f();",
* In N3242, decltype(f()) is const int;
* In N3290, decltype(f()) is int.

Regards,
Michel