Re: [boost] Re: erroneous use of BOOST_STATIC_CONSTANT ?

From: Toon Knapen (toon.knapen_at_[hidden])
Date: 2004-07-12 06:37:54

John Maddock wrote:

>>I wonder if it's possible to use preprocessor tricks to have
>>BOOST_STATIC_CONSTANT generate enums (on IBM only) whenever they will
>>fit?  After all, integral constants _can_ be managed by the
>>preprocessor.
> 
> 
> So they can, but not with BOOST_STATIC_CONSTANT as is:
> 
> BOOST_STATIC_CONSTANT(long long, value = 0ULL);
> 
> as far as I know there's no way to do different things depending upon the
> second argument here, but I'd love to be proved wrong (and be very impressed
> as well!).

We already have BOOST_WORKAROUND. What I can do is provide a 
BOOST_WORKAROUND that will use an enum if the datatype is not too wide. 
Simple but effective!

historical note: The reason I brought this up was because Mathias Troyer 
  asked me to remove the BOOST_NO_INCLASS_MEMBER_INITIALIZATION in the 
config for vacpp version 6. And indeed, vacpp can handle the 
initialization but does not comply with the DR (so one can argue if 
BOOST_NO_INCLASS_MEMBER_INITALIZATION should be defined or not). 
Defining it however caused a problem in the random library however 
(Mathias can you recall what exactly happened and why).

Next, should'nt it be a good idea to mention the policy on the out of 
line definition on http://www.boost.org/more/int_const_guidelines.htm
(I'm willing to do it but a language lawyer among us should probably 
best revise it before I commit it).