How to use register storage class with typedef?

I want to do this:

typedef register unsigned int _newint;

Basically, a concise alias of register unsigned int as _newint.

But an error, "more than one storage class may not be specified," occurs, underlining register.

I want to know if I can do this or not; if yes then how?

Solution

I want to know if I can do this or not, if yes then how?

Both typedef and register count as storage classes, though that's somewhat of a technicality in the case of typedef. You cannot declare any identifier to have more than one storage class, so the direct answer is no, you cannot do that.

You could conceivably use a macro instead of a typedef to achieve a similar effect:

#define _newint register unsigned int

void foo() {
    _newint x;
}

That is misleading, however, so you shouldn't.

More generally, you probably should not be using register storage class at all. Modern compilers don't need your help to figure out which variables to store in registers, and register is just a hint, so the only notable effect is that you are prevented (by rule) from taking the address of an object declared with that storage class.