Question

I have a NULL pointer named pTest. Is it possible to make the application crash immediately, if a function is invoked using the pointer.

Answer 1

Instead of using a raw pointer, you can create a protected pointer class (a form of smart pointer) that traps dereferences.

#include <stdexcept>

template<typename T>
class CheckedPointer
{
    T * ptr;
public:
    CheckedPointer(T * init = NULL) : ptr(init) {}
    T * operator->() const
    {
        if (ptr == NULL)
            throw std::runtime_error("dereference of NULL pointer");
        return ptr;
    }
    T & operator*() const
    {
        if (ptr == NULL)
            throw std::runtime_error("dereference of NULL pointer");
        return *ptr;
    }
    // ... more members to make this a useful class
};

class Test
{
public:
    void Foo() {}
};

int main()
{
    CheckedPointer<Test> pTest;
    pTest->Foo();
}

http://ideone.com/R4mUK