Question

Embarrassing though it may be I know I am not the only one with this problem.

I have been using C/C++ on and off for many years. I never had a problem grasping the concepts of addresses, pointers, pointers to pointers, and references.

I do constantly find myself tripping over expressing them in C syntax, however. Not the basics like declarations or dereferencing, but more often things like getting the address of a pointer-to-pointer, or pointer to reference, etc. Essentially anything that goes a level or two of indirection beyond the norm. Typically I fumble with various semi-logical combinations of operators until I trip upon the correct one.

Clearly somewhere along the line I missed a rule or two that simplifies and makes it all fall into place. So I guess my question is: do you know of a site or reference that covers this matter with clarity and in some depth?

Answer 1

I found the right-left-right rule to be useful. It tells you how to read a declaration so that you get all the pointers and references in order. For example:

int *foo();

Using the right-left-right rule, you can translate this to English as “foo is a function that returns a pointer to an integer”.

int *(*foo)();  // "foo is a pointer to a function returning a pointer to an int"
int (*foo[])();  // "foo is an array of pointers to functions returning ints"

Most explanations of the right-left-right rule are written for C rather than C++, so they tend to leave out references. They work just like pointers in this context.

int &foo;  // "foo is a reference to an integer"