Could someone please tell me if I'm reading the following correctly

	int myfunc(MyStruct *ms, void * (*allocF)(size_t s))

The second parameter above [void * (*allocF)(size_t s)], is a pointer to a function that accepts a size_t parameter and returns a void pointer? If so, I have two questions:

	1) Why is the function  pointed to being dereferenced? Why [(*allocF)] instead of [(allocF)]?

	2) Is [void function(size_t s) allocF] a suitable replacement or would it be better to use a delegate?

Thanks
-- 
Andrew C. Edwards
-----------------------------------------------------
The truth we call D, has passed through three stages:
  First ridiculed; Then violently opposed;
  And now, it is being accepted as self-evident.
Consequently:
  C/C++ is rapidly approaching Stage 5 (being forgotten)!

Tyro wrote:
> Could someone please tell me if I'm reading the following correctly
> 
>     int myfunc(MyStruct *ms, void * (*allocF)(size_t s))
> 
> The second parameter above [void * (*allocF)(size_t s)], is a pointer to a function that accepts a size_t parameter and returns a void pointer? If so, I have two questions:
> 
>     1) Why is the function  pointed to being dereferenced? Why [(*allocF)] instead of [(allocF)]?

It's not being dereferenced, the * just means allocF is a pointer (to a function). It's in parentheses because it would otherwise get parsed as a function returning void** (as opposed to a function _pointer_ returning void*), which is illegal as a parameter, afaik.

>     2) Is [void function(size_t s) allocF] a suitable replacement or would it be better to use a delegate?

Depends :) If myfunc is a C function, you have to use a function; if it's a D function, it's usually better to use a delegate..


xs0

Tyro wrote:
> Could someone please tell me if I'm reading the following correctly
> 
>     int myfunc(MyStruct *ms, void * (*allocF)(size_t s))
> 
> The second parameter above [void * (*allocF)(size_t s)], is a pointer to a function that accepts a size_t parameter and returns a void pointer? 

Yes.

<snip>
>     2) Is [void function(size_t s) allocF] a suitable replacement

No.  However, this is:

    int myfunc(MyStruct* ms, void* function(size_t s) allocF)

I always use the D function/delegate notation.  Much easier to read than the C notation.  Note also that the '*' has been attached to the type, which is more logical in D.

> or would it be better to use a delegate?

Whether you should use function or delegate depends on what you're going to pass in.

function - module level functions or static member functions
delegate - member functions acting on a specific object, or nested functions

Stewart.

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