Hi,
'memcpy' espects memory addresses. You need to use the reference operator (&) in order to get a struct address.
memcpy(&outer.nested, &inner, sizeof(INNER));
Anyway, you can't assign structs directly
outer.nested = inner; // error
...
INNER test = outer.nested; // error
Depending on how you do receive the INNER struct, you can perform two actions: memcpy, as explained, or save the reference of the incoming struct. Something like this:
typedef struct
{
int inside_element;
} INNER;
typedef struct
{
int outside_element;
INNER * nested; // a pointer to a INNER struct
} OUTER;
...
outer.nested = &inner; //reference!
...
printf("\nnested element: %d; other element: %d", outer.nested->inside_element, outer.outside_element);
// or
INNER * test = outer.nested;
printf("\nnested element: %d; other element: %d", test->inside_element, outer.outside_element);
Hope it helps.
Salud!
