Thread: Tricky typedef

What is the purpose of this?

typedef unsigned * (*item)(void* yyy);

What is the difference then between the a bove to the ordinary way?
The ordinary way is: typedef void (Item_t)(int)
What can be the usage of this?

Trying to explain the declaration... This:

Code:

unsigned int func( void *p );

Is a function named func which returns an unsigned int and takes a pointer to void as argument, right?

This:

Code:

unsigned int *func(void *p);

Is the same, but returns a pointer to unsigned int. So, this other one is a pointer to a function which returns a pointer to unsigned int and takes a pointer to void as argument:

Code:

unsigned int *(*funcptr)(void *);

Now we can transform this declaration in a typedef:

Code:

typedef unsigned int *(*funcptr_T)(void *);

And use the type funcptr_T, instead of that complicated declaration, for example:

Code:

typedef unsigned int *(*funcptr_T)(void *);

unsigned int *f( void *p ) { ... do something... }
unsigned int *g( void *p ) { ... do something else ... }

unsigned int *example( unsigned int n, void *arg )
{
  // table with pointers to functions.
  const static funcptr_T fptr[] = { f, g };

  if ( n < 2 )
    return fptr[n](arg);  // indirect call through a pointer.
  return NULL; 
}

Thanks flp1969, this is helpful