The macros for performing operations on structures are as follows:
Returns the size of the structure referred to by handle, according to its embedded data model.
Returns the indicated field in the data structure referred to by handle. This field is a non-pointer type.
Returns the indicated field in the data structure referred to by handle. This field is a pointer type.
Sets the indicated field in the data structure referred to by handle to value val. The type of val should match the type of fieldname. The field is a non-pointer type.
Sets the indicated field in the data structure referred to by handle to value val. The field is a pointer type.
Returns the address of the indicated field in the data structure referred to by handle.
Returns a pointer to the native structure described by handle.