type_traits: is_base_and_derived bug

From: David Abrahams (david.abrahams_at_[hidden])
Date: 2002-01-16 17:26:08

I think we need to check for Base == void; this case reports that void is a
base of BB:

#include <boost/type_traits/conversion_traits.hpp>
#include <iostream>

struct BB {};

#define print(x) std::cout << #x << " : " << x << std::endl
int main()
{
    print((boost::is_base_and_derived<void,BB>::value));
}

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