What is the meaning of void* volatile* in c++

Question

I am looking at the following code:

inline void* interlocked_read_acquire(void* volatile* x); 

and am wondering why not just a volatile void* as an argument. In general what is the semantics or definition of a volatile*? I am also making the assumption that you could use the volatile* qualifier with any other type besides void. Is that correct?

Answer 1

Use cdecl or the clockwise spiral rule to decipher C-style declarations :

void* volatile* x 

• declares x as pointer to volatile pointer to void

which is different from :

volatile void* x 

• declare x as pointer to volatile void