class B
{};
class BB : public B
{
};
class C
{
};
template<typename T>
struct DerivedFromB
{
	struct Small{char x;};
	struct Big{char x[2];};
	static Small match(B*);
	static Big match(...);
	enum {value = sizeof(match((T*)0)) == sizeof(Small)};
};
namespace support_static_assert
{
	template <bool x>
	struct STATIC_ASSERTION_FAILURE;
	template <>
	struct STATIC_ASSERTION_FAILURE<true> { enum { value = 1 }; };

	template<int x>
	struct static_assert_test{};
}
#define STATIC_ASSERT(x) typedef support_static_assert::static_assert_test< \
	sizeof(support_static_assert::STATIC_ASSERTION_FAILURE<(bool)(x) >) \
	>	static_assert_typedef
template <class B>
class A
{
	STATIC_ASSERT(DerivedFromB<B>::value);
};
int main()
{
	A<B> orz;
	A<BB> orz1;
	//A<C> orz2;
};