[cfe-dev] Guaranteed copy elision and GNU ?: operator

[Hal Finkel via cfe-dev]

On 10/25/2017 07:42 PM, Ronald Wampler wrote:
> On Wed, Oct 25, 2017 at 7:35 PM, Hal Finkel <hfinkel at anl.gov> wrote:
>> On 10/25/2017 02:54 PM, Ronald Wampler wrote:
>>> On Wed, Oct 25, 2017 at 2:09 PM, Hal Finkel <hfinkel at anl.gov> wrote:
>>>
>>> It prints 42 when compiled with c++14 and 0 with c++17 (c++1z).
>>>
>>> I also submitted this with a simpler case as
>>> https://bugs.llvm.org/show_bug.cgi?id=35039
>>
>> To ask the obvious question, given that this is a GNU extension, has this
>> been raised with the GCC developers? I imagine that we do want to match
>> GCC's behavior in this regard.
>>
> Argh! This is embarrassing. I'm on a Mac and when I installed gcc I forgot
> that `g++` is sym-linked to clang.
>
> It appears that gcc never allowed this code to compile to begin with. See
> godbolt: https://godbolt.org/g/8DdytF
>
> So I guess clang should give an error here too.

Ah, okay. Please update your bug report as well.

  -Hal

>
>
>>   -Hal
>>
>>
>>
>> --
>> Hal Finkel
>> Lead, Compiler Technology and Programming Languages
>> Leadership Computing Facility
>> Argonne National Laboratory
>>

-- 
Hal Finkel
Lead, Compiler Technology and Programming Languages
Leadership Computing Facility
Argonne National Laboratory