Re: [boost] type_traits for checking derived type

some code:

template <typename DerivedT> class A { BOOST_STATIC_ASSERT((boost::is_convertible<A<DerivedT>*, B*>::value)); [...] };

class B : public A<B> { };

I want to check if the template parameter really specifies a derived type. But the assert is always false. How can i solve this?

I think your code should be: template <typename DerivedT> class A { BOOST_STATIC_ASSERT((::boost::is_convertible<DerivedT*, A<DerivedT>*>::value)); // this should work as well: BOOST_STATIC_ASSERT((::boost::is_base_and_derived<A<DerivedT>, DerivedT>::value)); }; class B : public A<B> { }; However, the static asserts still always get triggered, and I'm not sure why: any language lawyers understand this? John.