Re: [boost] type_traits / MPL interoperability

From: David Abrahams (dave_at_[hidden])
Date: 2005-11-22 07:28:51

"John Maddock" <john_at_[hidden]> writes:

>>> integral_constant<bool,b> derives from mpl::bool_<b> for backwards
>>> compatibility.
>>
>> For still more backward compatibility we ought to have a conversion
>> in the other direction.
>
> I realised that right after I posted (as usual, post first think later. 
> Doh!)
>
> Are there any drawbacks to making the constructors of these types 
> non-trivial?

Only the usual ones, I guess ;-)

>>> Stupid question but why doesn't your function do:
>>>
>>> template <class T>
>>> typename is_fundamental<T>::type f(T)
>>> {
>>>     return is_fundamental<T>::type();
>>> }
>>
>> Stupid answer: broken compiler workaround.
>>
>> Anyway, this isn't a big deal.  Maybe not even worth acting on.
>
> OK, how about just using "is_fundamental<T>()" directly, no need to
> access it's ::type member at all really ?

It's not an obstacle for me at the moment, so I'm okay -- but it did
surprise me.

-- 
Dave Abrahams
Boost Consulting
www.boost-consulting.com