C++ Primer Plus

Passing Structure Addresses

Suppose you want to save time and space by passing the address of a structure instead of passing the entire structure. This requires rewriting the functions so that they use pointers to structures. First, let’s look at how you rewrite the show_polar() function. You need to make three changes:

• When calling the function, pass it the address of the structure (&pplace) rather than the structure itself (pplace).

• Declare the formal parameter to be a pointer-to-polar—that is, type polar *. Because the function shouldn’t modify the structure, use the const modifier.

• Because the formal parameter is a pointer instead of a structure, use the indirect membership operator (->) rather than the membership operator (dot).