Re: [Boost-users] problems with C++ integer types

Subject: Re: [Boost-users] problems with C++ integer types
From: Robert Ramey (ramey_at_[hidden])
Date: 2012-01-29 23:15:46

Eric Niebler wrote:
> On 1/29/2012 3:01 PM, Robert Ramey wrote:
>> I'm very confused about a number of things related to C++ standard
>> and boost libraries
>> dealing with numeric types.
> <snip>
>
> All good questions. You're really asking about any user-defined
> numeric-like type, not just boost ones. Probably best to ask on
> comp.lang.c++.moderated. If you get an answer there, please post it
> here.

Hmmm - that was good advice.  I found

http://groups.google.com/group/comp.lang.c++.moderated/browse_thread/thread/a6eed812f6c51f9/8fe717943806e700?lnk=gst&q=numeric_limits+specialization#8fe717943806e700

which - among other things says:

"*YOU* are allowed to provide a specialization for a user defined
type.  The implementation is not allowed to provide a specialization
for a non-fundamental standard type."

which is the answer to my question.

it also answers indirectly my other questions. In particular
I realize now that boost/type_traits/is_integral.hpp is should't
be implemented in terms of numeric_limits - it's fine the way
it is. Also boost/type_traits/make_signed can't be implemented
in terms of numeric_limits either so IT'S fine the way
it is. If I want have make_signed<safe_integer.. I'll have
to specialize it myself - which OK.

Soooo, all in all a false alarm.

Robert Ramey