C++ the meaning of getting size of a array -

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here macro getting array size

#define array_size(array) \ (sizeof( array ) / (sizeof( array[0] ) * (sizeof( array ) != sizeof(void*) || sizeof( array[0] ) <= sizeof(void*)))

i think (sizeof( array ) / (sizeof( array[0] )) enough size of array.

i guess part

(sizeof( array[0] ) * (sizeof( array ) != sizeof(void*) || sizeof( array[0] ) <= sizeof(void*))

is avoid whole thing divided zero, explain?

thanks in advance.

cheers,

multiplying sizeof array[0] in divisor by

(sizeof( array ) != sizeof(void*) || sizeof( array[0] ) <= sizeof(void*))

makes divisor 0 if

sizeof array == sizeof(void*)

and

sizeof array[0] > sizeof(void*)

in cases, division 0 during compilation, cause compilation fail.

these checks attempt detect arguments pointers (be result of array-to-pointer conversion or not), since 1 can't know how large "array" pointer points using quotient.

it fails if other pointer types have different sizes void*, , doesn't detect pointers things not larger void*s. more harm lulling author in false sense of security.


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