Re: C++ compatibility

["Pelaia II, Tom" <pelaiata@ornl.gov>]

Hi Jeff,

Thanks for the feedback! There's no rush. 

As Andrew suspected, I was attempting to compile using Clang.

Thanks,
Tom


On Mar 11, 2011, at 9:27 PM, Jeff Hill wrote:

> Hi Tom,
> 
> I wasn’t aware of that, and it probably needs to 
> be fixed. The reference counting mutex class on the 
> cvs trunk might be a clean workaround. Also, presumably 
> the quick fix is to just use instead, a mutable 
> _pointer_.
> 
> Hopefully, I can get to this on Monday.
> 
> Jeff
> ______________________________________________________
> Jeffrey O. Hill           Email        johill@lanl.gov
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> 
>> -----Original Message-----
>> From: Andrew Johnson [mailto:anj@aps.anl.gov]
>> Sent: Friday, March 11, 2011 12:39 PM
>> To: Jeff Hill; EPICS core-talk
>> Cc: Pelaia II, Tom
>> Subject: Fwd: C++ compatibility
>> 
>> Hi Jeff,
>> 
>> An issue for you from the CA client library.  Tom's right about the rule
>> (this
>> is not a recent change either, it's present in my 1998 first edition of
>> the
>> spec), but I have no idea why the restriction exists.  I'm guessing that
>> Apple's clang C++ compiler has started to check this.
>> 
>> Thanks Tom.
>> 
>> - Andrew
>> 
>> ----------  Forwarded Message  ----------
>> 
>> Subject: C++ compatibility
>> Date: Friday 11 March 2011
>> From: "Pelaia II, Tom" <pelaiata@ornl.gov>
>> To: Andrew Johnson <anj@aps.anl.gov>
>> 
>> Hi Andrew,
>> 
>> I believe there is an error in some EPICS base source files in which
>> reference
>> members are declared mutable:
>> 
>> In file included from ../cac.cpp:39:
>> ../cac.h:269:5: error: 'mutable' cannot be applied to references
>>    mutable epicsMutex & mutex;
>>    ^
>> ../cac.h:270:5: error: 'mutable' cannot be applied to references
>>    mutable epicsMutex & cbMutex;
>>    ^
>> In file included from ../cac.cpp:47:
>> ../udpiiu.h:152:5: error: 'mutable' cannot be applied to references
>>    mutable epicsMutex & cbMutex;
>>    ^
>> ../udpiiu.h:153:5: error: 'mutable' cannot be applied to references
>>    mutable epicsMutex & cacMutex;
>>    ^
>> 
>> 
>> The C++ specification (section 7.1.1 item 10) explicitly forbids mutable
>> reference members:
>> http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2011/n3242.pdf
>> 
>> Best regards,
>> Tom
>> ___________________________________________________
>> Tom Pelaia  |  homepage: http://www.ornl.gov/~t6p
>> 
>> -----------------------------------------
>> --
>> An error is only a mistake if you don't learn from it.
>> When you learn something from it, it becomes a lesson.
>