Question

Consider the following type declarations

TYPE A A Ti 12 T3 T4 TS TO T7 TH intage pointer to float: pointer to Integer structurex Integer structure X A; next pointer to inte structura inter l oat structure float: aInteger structure la pointer to 15 pointer to TS structure la pointer to T i pointer to 15 structure la pointer to T i pointer to structure la pointer to 17 pointer to TS pointer to T7 pointer to 15 pointer to T pointer to T10 T 1 7 array 4 rows 5 columns array 1951 of T array [41151 of 17 T10 Assuming the most permissive definition of structural equivalence, which types are structurally equivalent?

Answer 1

Two types are Structurally Equivalent if types of their each component are same and are in same order as well.

Type A1 is integer

Type A2 is pointer to float. We know that pointer is always integer type so A2 is also integer

Type A3 is pointer to integer. Pointer is always integer type so A3 is also integer.

Type T1 is structure with one component of integer type. This will be treated as integer only.

Type A1, A2, A3 and T1 all are having structural equivalence.

Type T2 is structure with two components. First is of type A1 which means integer and second is pointer to integer.

Type T3 is structure with two components. First is integer type and second is float type.

Type T4 is structure with two components. First is float type and second is integer type.

Type T2, T3 and T4 are not having structural equivalence between any pair of them.

Type T5, T6, T7 and T8 all are having structural equivalence because each of them have three components of integer types (pointers are of type integer).

Type T9 and T10 both are having structural equivalence because they are having same number of components and structurally equivalent components.