Q:

volatile unsigned * in C++

Possible Duplicate:
Unsigned keyword in C++ 

I'm currently learning about how directly access memory mapped devices (specifically Raspberry Pi GPIO) and in some sample code I see the following:
// I/O access
volatile unsigned *gpio;

What confuses me is no type seems to be defined. Is this valid C++ and if so what does the above code declare?
Thanks!
PS: I know about the Raspberry Pi StackExchange but this question is just related to C++ syntax.

A:

unsigned alone is the same as unsigned int.
Same as this:
volatile unsigned int *gpio;

Just shorter.

