Re: [Boost-users] [mpl] Is it possible to mpl_assert depending on the derivation of a class

on Tue Aug 21 2007, Martin Apel wrote:

Hughes, James wrote:

...

Hello all,

I want some template code to assert if the passed in template type is NOT derived from a particular base class.

I've looked through the Template Metaprogamming book, but haven't seen anything that can do this, but I seem to remember something along those lines.

Can anyone help?

James

Hi James,

the easiest way is something like the following:

#include #include

BOOST_STATIC_ASSERT (boost::is_base_of::value);

BOOST_MPL_ASSERT((boost::is_base_of)) Don't use BOOST_STATIC_ASSERT if you can help it. It gives far inferior results when assertions fail. -- Dave Abrahams Boost Consulting http://www.boost-consulting.com The Astoria Seminar ==> http://www.astoriaseminar.com