struct dont_care { dont_care(...); };
struct A {};
struct B { B(const A&) {} };

struct C
{
#ifdef USE_TEMPLATE
    template < typename T > static void f(const T&) {}
#else
    static void f(const B&) {}
#endif
    static void f(dont_care) {}
};

int main()
{
    C::f(A());
}