Using a member accessor in an assignment..

[Shaderhacker]

I'm trying to use member access functions to assign values to them. It's not working with pointers. For example:

class Foo
{

public:
Foo();
void testFunc();
float* myPointer() { return _myPointer; }

private:

float* _myPointer;

}

void Foo:testFunc()
{
   
float arr[] = { 1, 2 , 3, 4 };

myPointer() = &arr[2]; <========= Fails here!!  Why??

}

[MrViggy]

Please use code tags.

The line:

myPointer() = &arr[2];

Makes no sence. It doesn't modify anything. It looks like you want a "setter" function in your class:

class Foo
{
   public
      ...
      void SetPointer(float *pFloat) { _myPointer = pFloat; }
      ...
};

Viggy

[MrViggy]

Let me expand on that... The function 'myPointer()' doesn't return a reference to anything, it returns the actual value of the variable. So, your statement would would evaluate to:

0x12345678 = 0x98765432

Viggy

[Shaderhacker]

Let me expand on that... The function 'myPointer()' doesn't return a reference to anything, it returns the actual value of the variable. So, your statement would would evaluate to:

0x12345678 = 0x98765432

Viggy

Excellent explanation!

OK. I guess I *DO* want a reference returned to my pointer. I like using name() as a variable instead of the actual name. So, could I do this:

float& B() { return &b; }

..

private:
float* b;

Then do:

B() = &of_something[3];

-M

[Bench_]

One of the core principles behind Object-oriented design is Encapsulation. part of this is not leaking out references to private data members. (implementation details)

If you're going to do this, you may as well declare 'b' as a public data member... or better still, take a good look at the design of your program, and see what needs to be improved, so that you've got no need to directly play about with class data members. (MrViggy's original suggestion of using a 'set' member function would be the obvious solution, without knowing more details of the problem)

[Shaderhacker]

One of the core principles behind Object-oriented design is Encapsulation. part of this is not leaking out references to private data members. (implementation details)

If you're going to do this, you may as well declare 'b' as a public data member... or better still, take a good look at the design of your program, and see what needs to be improved, so that you've got no need to directly play about with class data members. (MrViggy's original suggestion of using a 'set' member function would be the obvious solution, without knowing more details of the problem)

OK. I've looked over the code and design more carefully, it seems like the only functions that will access the private class members is the member functions within the class. Having said that, I've removed the accessor.

-M

[ka3ak]

for educational purposes:

float *&myPointer() { return _myPointer; }