Macro to both get (void*) address of item and length, for arrays and structs

Answer 1

I'm not sure what problem you are having with &array1. This C++ worked exactly as expected (all values the same)

int main(int argc, char* argv[])
{
    int array1[10];

    printf("%x %x\n", array1, &array1);
    cout << array1 << " " << &array1 << endl;

    void* ptr1 = array1;
    void* ptr2 = &array1;

    printf("%x %x\n", ptr1, ptr2);
    cout << ptr1 << " " << ptr2 << endl;
    return 0;
}

Answer 2

If the array is in fact an array (which seems to be required for the sizeof to work), why don't you just use the simple macro:

#define MUNGE_THING( x ) munge_thing((void*)&(x), sizeof(x))

That should work both for arrays and structs:

int array[10];
assert( (void*)array == (void*)&array );

You have tagged the question as both C and C++, in C++ you can use templates and avoid the macros all together.

Answer 3

Okay, I see my confusion. In C++, the type of &array is not compatible with the type of the array, and as the linked discussion notes, (&array)+1 is not the same as (array+1), but casting the unsubscripted pointers does in fact yield the proper results. The distinctions between arrays and pointers in C are very confusing. Thanks for the assistance.