Re: [boost] checking __INTEL_COMPILER == 9999

Subject: Re: [boost] checking __INTEL_COMPILER == 9999
From: John Maddock (jz.maddock_at_[hidden])
Date: 2015-11-14 07:21:32

On 13/11/2015 22:27, Edward Diener wrote:
> On 11/13/2015 2:45 PM, Blower, Melanie wrote:
>>   A few years ago, circa 2010, the Intel 12.x compiler was released 
>> without having a correct value for the macro __INTEL_COMPILER.   It 
>> was released using the development-only version number 9999 instead 
>> of the correct value 12xx. Later on, an Intel 12.x compiler was 
>> updated to remove this problem and the version number made correct.
>
> You did not explain why the check for '9999' causes problems or why it 
> is incorrect in the cases in which it is used.
>

Intel use version 9999 for their internal testing of the next release, 
but a compiler with that version number accidentally slipped out into 
the wild as well.  Boost.Config has no way of distinguishing between 
them, I'm not sure, but this may effect users beta-testing Intel's 
products as well as their development team.

>>
>> Meanwhile, since boost needed to add some workarounds, there was code 
>> added in a couple of boost files to check for version 9999.  The 
>> check for 9999 in boost causes trouble in our current development 
>> compiler in-house testing.  Is it possible to have this version 
>> checking removed from the boost sources?  There's no advantage to 
>> boost users, and possibly a disadvantage if someone is still using a 
>> not-updated 12.x compiler. But hopefully that is unlikely, we're 
>> currently shipping our 16.x compiler.
>
> Whether you think a Boost library should support older versions of a 
> compiler or not it is up to the library implementor what versions of a 
> given compiler are supported. It is usually considered rude to drop 
> support for a compiler/version in a particular Boost library without 
> making some prior announcement about it and waiting at least one 
> release after the announcement.
>

That's normally true.  However, in this case the effected version 
appears to be no longer available from Intel's site - only 12.0 update 5 
and later - so I guess I'm somewhat sympathetic to the change in this case.

John.