Typedef'ing a function

[Enrico Porreca]

Is the following a legal typedef? (gcc -Wall -ansi -pedantic says it's ok)

typedef void Callback(void *obj);

I mean "a Callback is a function taking void * and returning void" (not
"a pointer to function"). Then of course I would use pointers to
Callback, like

void apply(Callback *f, void *a[], size_t size)
{
size_t i;

for (i = 0; i < size; i++)
f(a);
}

I prefer it to

typedef void (*Callback)(void *obj);

because I don't like hiding pointers behind typedefs.

 

[S.Tobias]

Is the following a legal typedef? (gcc -Wall -ansi -pedantic says it's ok)

typedef void Callback(void *obj);

I mean "a Callback is a function taking void * and returning void" (not
"a pointer to function"). Then of course I would use pointers to
Callback, like

void apply(Callback *f, void *a[], size_t size)
{
size_t i;

for (i = 0; i < size; i++)
f(a);
}

I prefer it to

typedef void (*Callback)(void *obj);

because I don't like hiding pointers behind typedefs.

Yes (to the typedef) and yes (to its use).

The typedef declaration could be shortened to:
typedef void Callback(void *);
(ie. you don't have to name the parameter).

 

[Malcolm]

The typedef declaration could be shortened to:
typedef void Callback(void *);
(ie. you don't have to name the parameter).

Though normally it is a good idea.

typedef void PixelPutter(int, int, int);
typedef void PixelPutter(int x, int y, int colour);