Compiler Warning C0421

Message: Use keyword EXTENDS for inheritance of interfaces instead of IMPLEMENTS

Possible error cause: An interface extends another interface, but uses the IMPLEMENTS keyword.

Error correction: Replace the IMPLEMENTS keyword with the EXTENDS keyword.

Example of the warning:

INTERFACE ITF

INTERFACE ITF_1 IMPLEMENTS ITF

The declaration of the interface ITF_1 produces the following warning.

Message:

C0421: Use keyword EXTENDS for inheritance of interfaces instead of IMPLEMENTS