evaluate more complex expressions using gdb

[Bram Kuijper]

Hi all,

again a newbie question: can I also evaluate the result of subtractions, 
additions using the display command? Like some pointer arithmetics:

display pointer1 - start_pointer

If I do this, gdb gives me the following error:

Disabling display 6 to avoid infinite recursion.
6: pointer1 - start_pointer = One of the arguments you tried to pass to 
operator- could not be converted to what the function wants.

Is there any way to to this using gdb?

thanks,
Bram