problems compiling template class using is_class and is_arithmetic

[sheff]

Consider this code:

class C
{
public:
	template <typename T>
	typename boost::enable_if_c<boost::is_class<T>::value, void>::type 
	f(T& t)
	{

	}

	template <typename T>
	typename boost::enable_if_c<boost::is_arithmetic<T>::value, void>::type 
	f(T& t)
	{

	}
};

void main()
{
	C c;
}

it compiles without fault, but the following code:

class A {};

template <class T1>
class B : public T1
{
public:
	template <typename T2>
	typename boost::enable_if_c<boost::is_class<T2>::value, void>::type 
	f(T2& t)
	{

	}

	template <typename T2>
	typename boost::enable_if_c<boost::is_arithmetic<T2>::value, void>::type 
	f(T2& t)
	{

	}
};

void main()
{
	B<A> a;
}

fails to compile

[John Maddock]

That needs to be:

template <class T1> class B : public T1 { public:

template <typename T2> typename boost::enable_if<boost::is_class<T2>, void>::type f(T2& t) {

}

template <typename T2> typename boost::enable_if<boost::is_arithmetic<T2>, void>::type f(T2& t) {

}

};