Re: [boost] mpl, type_traits and VC7.1

From: John Maddock (john_at_[hidden])
Date: 2004-01-10 06:11:10

> I'm fixing the compilation problems with VC7.1 for the recently accepted
> Numeric Conversions Library and found the following:
>
> (1)
> I erroneously used a construct of the follwing form:
>
> typedef typename boost::is_same<T,S>::type is_trivial ;
>
> typedef typename boost::mpl::if_<is_trivial,ABC,DEF>::type type ;
>
> The error is in the "::type" after is_same<>; mpl::if_ can take the traits
> as is, without the "::type"
>
> However, that code did pass many of the other compilers, so that "::type"
> does exist in some cases.
>
> Is this a bug in the VC7.1 version of "is_same"? That is, was it intended
to
> have "::type"?

Not yet, the ::type member is not part of the documented interface, but we
do need to deal with that sometime.

John.