[RFC] Return Type Declarations

My dear Internals friends, I have spent the last month drafting an RFC that allows return types: https://wiki.php.net/rfc/returntypehinting Notable items: - Differences from past RFCs are summarized in the RFC: https://wiki.php.net/rfc/returntypehinting#differences_from_past_rfcs - The patch includes basic opcache and reflection support. It also has phpt tests. - Informal performance tests indicate that the patch did not fubar performance; if desired a more detailed test can be conducted before voting. - This RFC does not add, modify, or remove keywords at all; this notably excludes type-hints for scalars. Supporting scalar type declarations is outside the scope of this RFC; if you are interested in supporting scalar type declarations please discuss it elsewhere. As a friendly reminder, everyone on this list is interested in developing a better PHP and the definitions of 'better' vary from person to person. Please be civil and constructive while discussing this RFC. Thank you! Some thanks, regardless if the RFC is accepted: - For providing a patch: Joe Watkins. - For helping me iterate on RFC drafts: Bob Wienand, Nikita Popov and Anthony Ferrara - For previous RFCs on this topic: Felipe Pena and Will Fitch. I gleaned valuable knowledge from your proposals and the discussion around them.