Re: [boost] suggestion on assertion macros

Subject: Re: [boost] suggestion on assertion macros
From: Mateusz Loskot (mateusz_at_[hidden])
Date: 2010-03-14 10:54:54

Roland Bock wrote:
> Mateusz Loskot wrote:
>> Emil Dotchevski wrote:
>>  
>>> On Sat, Mar 13, 2010 at 2:43 AM, Andrzej Krzemienski
>>> <akrzemi1_at_[hidden]> wrote:
>>>    
>>>> This is a good addition to assertions, but once we decide that we are
>>>> improving assertions, there is much more that needs an improvement.
>>>> Most of them are listed in the thread on Contract++ library (proposed
>>>> for Boost) that you are already referring to. But let me list the
>>>> potential improvements here.
>>>>       
>>> Why don't we leave assertions alone? Anything you do to "improve" them
>>> makes them more tolerable which makes them something other than
>>> assertions.
>>>
>>> Assertions should print a message and exit.     
>>
>> Well said.
>>
>> The idea of "Be able to disable some assertions, " sounds
>> especially weird. Assertions are not for purpose of logging
>> and such. Categories of assertions severity make little
>> sense to me.
>>
>> Best regards,
>>   
> 
> I couldn't agree more, but removing the compile time warning in cases
> like the following does not change the nature of assertions.
> 
> void my_method(const int& my_param)
> {
>    assert(my_param);
> }
> 
> Currently I get compiler warnings about my_param being unused when
> compiling with NDEBUG defined.

Yes, that is a problem though of different nature than categories of
assertions.

> I'd be glad to get rid of them. And I
> certainly do not want to have my code sprinkled with
> 
> #ifdef NDEBUG
> void my_method(const int&)
> #else
> void my_method(const int& my_param)
> #endif
> {
>    assert(my_param);
> }

AFAIK, this is an issue of particular implementation you use.
The assert macro from GNU C Library wraps its argument
cast to void if NDEBUG is defined. No warning is issued.

Best regards,
-- 
Mateusz Loskot, http://mateusz.loskot.net
Charter Member of OSGeo, http://osgeo.org