====== PHP RFC: Additional soft reservations for PHP 7 ======
  * Date: 2015-07-03
  * Author: Nikita Popov <nikic@php.net>
  * Status: Under Discussion
  * Previous discussion: http://markmail.org/message/ovvnz5p2o6q7ebjl

===== Introduction =====

A number of type names were already [[https://wiki.php.net/rfc/reserve_even_more_types_in_php_7|soft-reserved for PHP 7]], which means that we reserve the right to introduce these in a minor release and as such strongly discourage their use, however no actual error or warning will be thrown if they are used against this recommendation. This RFC proposes a number of additional soft reservations, which have been previously missed.

Each of the proposed reservations is listed separately in the following. Votes will also happen separately. This RFC is open to additional suggestions.

===== Reservations =====

All reservations are case-insensitive.

==== void ====

**Where**: As the last segment of a class, interface or trait name. As such the names ''Void'' and ''Foo\Bar\Void'' are reserved, while ''Foo\Bar\MyVoid'' and ''Void\Foo\Bar'' are okay.

**Why**: ''void'' is a likely candidate for the demarcation of void functions (which do not return a value). Alternatively ''null'' can be used for this purpose, which is already reserved. However both possibilities should be kept open until we reach a decision on this question.

==== enum ====

**Where**: In any context which is not protected by the [[https://wiki.php.net/rfc/context_sensitive_lexer|context sensitivity RFC]]. This includes any segment of class, interface, trait and function names.

**Why**: There already is an [[https://wiki.php.net/rfc/enum|enum RFC]] which will be proposed for PHP 7.x and requires this reserved keyword.

===== Backward Incompatible Changes =====

Code using the aforementioned names (in the relevant contexts) should be changed to use a different name. However this is not strictly required.

===== Proposed Voting Choices =====

Votes will be per name and require 2/3 majority.