C语言：隐式指针解引用

Question

In C, is it possible to define an alias / shortcut for a dereferenced pointer?

Ie assuming a definition like:

void * ptr_to_my_variable = 0x2ff00000;

Is it possible to define a my_variable symbol that corresponds to *ptr_to_my_variable , such that:

*ptr_to_my_variable = 321;
my_variable = 123;
if (my_variable == *ptr_to_my_variable) printf "aliasing/shortcut works";

The only solution I can think of is:

#define my_variable *my_variable
int my_variable = (int *) 0x2ff00000;

my_variable = 123;

But this is clearly asking for trouble...

Answer 1

No, there is no trick that would let you dereference a pointer implicitly.

However, preprocessor trick that youmentioned in the edit lets you hide the explicit dereference, making it look implicit:

#define my_alias (*my_var_ptr)

Note, however, that you should place parentheses around the expression, which wiuld save you from trouble when you write

my_alias++;

Answer 2

Nope, the #define is the only way to do this in C.

C++ has things called "references" which are implicitly dereferenced, but can (must?) alias other objects. You'd have to ask somebody else about the details. But C does not support any such thing.