c++ const member function that returns a const pointer.. But what type of const is the returned pointer?

Question

I apologize if this has been asked, but how do I create a member function in c++ that returns a pointer in the following scenerios: 1. The returned pointer is constant, but

Answer 1

int *const func() const

You cannot observe the const here except for a few cases

• Taking the address of func.
• In C++0x, directly calling func with the function-call syntax as a decltype operand, will yield int * const.

This is because you return a pure pointer value, that is to say a pointer value not actually stored in a pointer variable. Such values are not const qualified because they cannot be changed anyway. You cannot say obj.func() = NULL; even if you take away the const. In both cases, the expression obj.func() has the type int* and is non-modifiable (someone will soon quote the Standard and come up with the term "rvalue").

So in contexts you use the return value you won't be able to figure a difference. Just in cases you refer to the declaration or whole function itself you will notice the difference.

const int* func() const

This is what you usually would do if the body would be something like return &this->intmember;. It does not allow changing the int member by doing *obj.func() = 42;.

const int * const func() const

This is just the combination of the first two :)