🔒 Locked

Macro Hassels

Started by Wyrframe Nov 28, 2001 at 1:00 AM 3 replies 350+ views

Original Post

Nov 28, 2001 at 1:00 AM

I''ve checked reference books. I''ve checked Online Help. I''ve searched about 18% of the net (or at least it feels like it...) I want to make a macro that looks like this...


#define DelPtr(ptr) {delete ptr; ptr = NULL;}

Now, that is what I originally thought I could do. Now, I''ve reconsidered, and I think that this will work...


_inline void DelPtr(void &*ptr) {
   delete ptr;
   ptr = NULL;
}

Could anyone tell me how to do this? I want to make a quick little inline or macro function that will do this (Delete and NULL a pointer), but neither of these attempts work with my compiler! I''m using Borland''s 5.5 32-bit compiler, if that makes a difference...

strtok

Nov 28, 2001 at 1:23 AM

Try this:

_inline void DelPtr (void **ptr)
{
delete *ptr;
*ptr = NULL;
}

Then in your code you do this:

DelPtr((void **)&some_pointer);

The compiler doesn''t like it if you don''t cast it to a (void **).

Advanced Bug

Nov 28, 2001 at 4:23 AM

I think this problem can be solved using function templates. Write something like this:

  
template<class T>
inline void DeletePtr(T*& pT)
{
  delete pT;
  pT = 0;
}
 
 
int* pInt = new int(10);
DeletePtr(pInt);

T*& is reference to pointer so it is passed by reference.

Void

Nov 28, 2001 at 8:42 PM

Continue searching the net for smart pointers.

Check out www.boost.org

SteveC

Nov 29, 2001 at 10:26 AM

Advanced Bug''s solution is the right way to go.

delete needs to have the correct type.

that''s the reason it works as the macro - the code just gets copied in there by the preprocessor, but not as an inline without templates.

Topic Locked

This topic has been locked by a moderator. New replies are not allowed.