A pointer of variable or a function?

[fitatc]

There is a macro _countof, the define is

template <typename _CountofType, size_t _SizeOfArray>
char (*__countof_helper(UNALIGNED _CountofType (&_Array)[_SizeOfArray]))[_SizeOfArray];
#define _countof(_Array) sizeof(*__countof_helper(_Array))

It confuse me that __countof_helper is a very weird pointer. At first glance, I thought it is a pointer of array, but, how can an variable can have an "()" suffix???

[loyal ginger]

It's a template of a function pointer array.

[fitatc]

shouldn't a function pointer's size be 4? how can a sizeof(*funcPtrArray(param)) turn out to be some relation with ReturnValTypeSize

modified on Sunday, January 31, 2010 9:20 PM

[Graham Breach]

It declares a function that takes an array and returns an array of char with the same number of elements. The sizeof operator acts on the returned array to give the number of elements.

[fitatc]

This makes sense. Thank you very much :)