[php-src] Issue #8156: Classes extending `SplFixedArray` can not implement `RecursiveIterator`

Issue: https://github.com/php/php-src/issues/8156 Comment Author: ghostwriter Implementing both Iterator and IteratorAggregate is a problem, because they are identical behaviors that are interchangeable. A Fatal error thrown when both Iterator and IteratorAggregate are implemented on the same class is acceptable. A Fatal error thrown when an IteratorAggregate and an interface that extends Iterator is implemented on the same class is undesired. eg RecursiveIterator * why is implementing IteratorAggregate not sufficient for RecursiveIterator's request for an Iterator? * was this change in behavior discussed anywhere? to read and learn why this current behavior is preferable. * why is this behavior is not documented, if it is in fact the intended behavior? if "help wanted", where can we find instructions on how we can contribute? If you're willing to discuss, reopen this issue.