Determining wether a class has a certain member?

Answer 1

There is indeed:

typedef char (&no_tag)[1];
typedef char (&yes_tag)[2];

template < typename T, void (T::*)() > struct ptmf_helper {};
template< typename T > no_tag has_member_foo_helper(...);

template< typename T >
yes_tag has_member_foo_helper(ptmf_helper<T, &T::foo>* p);

template< typename T >
struct has_member_foo
{
    BOOST_STATIC_CONSTANT(bool
        , value = sizeof(has_member_foo_helper<T>(0)) == sizeof(yes_tag)
        );
};

struct my {};
struct her { void foo(); };

int main()
{
    BOOST_STATIC_ASSERT(!has_member_foo<my>::value);
    BOOST_STATIC_ASSERT(has_member_foo<her>::value);

    return 0;
} 

Copy-pasted from here.

Edit: Update the code, which is compliant AFAIK. Also note that you have to know the arguments of the return type of the method you're checking for.