Re: [boost] MPL not_ etc. questions

From: Aleksey Gurtovoy (agurtovoy_at_[hidden])
Date: 2003-09-06 03:14:38

Jaakko Jarvi wrote:
> > Assuming that the latter version is spelled 'enable_if_c', making the
former
> > work is as simple as
>
> > template< typename C, ... >
> > struct enable_if
> >     : enable_if_c<C::value, ...>
> > {
> > };
>
> This is what we are using. The documentation of not_ always uses
> typedef not_<f>::type and doesn't mention that it contains a member
> named value.

Hmm, you are right. It should be more like this:

    Expression:         'not_<f>'
    Expression type:    A model of bool Integral Constant
    Semantics:          Equivalent to 'bool_<(!f::type::value)> '

Fixed in the sources.

>
> Are the docs on www.boost.org out of date?

Not really, may be only a little.

> We don't have the boostbook
> toolchain up so we don't have the latest CVS version of the docs.
> The tutorial seems to be using bool_c which is not documented in the
> reference manual (that uses bool_ , are they the same thing or is
> bool_ something different?).

They are the same.

> Also, bool_, int_, ... are not in the categorized index.

They are in the index -
http://www.boost.org/libs/mpl/doc/ref/Integral_constant_classes.html, but
they are not documented in detail, yes. These, and the update of the
tutorial are on my todo list.

Thanks for the comments,
Aleksey