SFINAE

#include <stdio.h>

template <class T>

struct is_pointer

{

template <class U>

static char is_ptr(U *);

template <class M, class C>

static char is_ptr(M C::*);

template <class U>

static char is_ptr(U(*)());

template<class ...>

static double is_ptr(...);

enum { value = sizeof(is_ptr((T)(0))) == sizeof(char) };

};

template<typename T>

struct has_no_destroy {

template<typename C>

static char test(decltype(&C::no_destroy));

template<typename ...>

static int test(...);

const static bool value = (sizeof(test<T>(0)) == 1);

};

struct Foo {

int bar;

};

void testTypeCheck() {

typedef int * IntPtr;

typedef int Foo::* FooMemberPtr;

typedef int(*FuncPtr)();

printf("%d\n", is_pointer<IntPtr>::value);        // prints 1

printf("%d\n", is_pointer<FooMemberPtr>::value);  // prints 1

printf("%d\n", is_pointer<FuncPtr>::value);      // prints 1

printf("%d\n", is_pointer<int>::value);          // prints 0

}

int main()

{

testTypeCheck();

getchar();

}