🚀 go-pugleaf

In <Pine.ULT.3.91.951020083514.12953B-100000@mars.dsv.su.se> Jens M Andreasen <jens-and@dsv.su.se> writes:


>
>On 19 Oct 1995, Peter Seebach wrote:
>
>> In article <Pine.ULT.3.91.951019204530.7241B-100000@mars.dsv.su.se>,
>> Jens M Andreasen  <jens-and@dsv.su.se> wrote:
>> Re: >static int i = 1 ? 3 : ( 1, 2);
>> 
>> >I interprete that as a way of saying that you are allowed to obfuscate 
>> >your constants any way you like, as long as they remain constants. There is 
>> >nothing in the expression above that could ever be nothing but a constant.
>> 
>> Except that the standard *EXPLICITLY* says that a "constant expression"
>> *CANNOT* contain a , operator.  Period.
>
>Period what? I did an example parsing showing that the comma will 
>disappear , vanish, go out of existence, DIE, or whatever parafrase ...

Nope.  It won't disappear _before_ the compiler "sees" it.  And it will
see it in a context where only a _constant expression_ is allowed.  But
constant expressions can't contain the comma operator (the standard says
so) hence the compiler MUST emit a diagnostic for that translation unit.

What is so difficult to understand?

Dan
--
Dan Pop
CERN, CN Division
Email: Dan.Pop@mail.cern.ch 
Mail:  CERN - PPE, Bat. 31 R-004, CH-1211 Geneve 23, Switzerland