rfc:inheritance_private_methods

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rfc:inheritance_private_methods [2020/04/17 15:44] – pmmagarfc:inheritance_private_methods [2020/07/17 14:59] (current) – pmmaga
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   * Date: 2020-04-16   * Date: 2020-04-16
   * Author: Pedro Magalhães, pmmaga@php.net   * Author: Pedro Magalhães, pmmaga@php.net
-  * Status: Draft+  * Status: Implemented 
 +  * Target: 8.0
   * First Published at: http://wiki.php.net/rfc/inheritance_private_methods   * First Published at: http://wiki.php.net/rfc/inheritance_private_methods
  
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 <code> <code>
 +Warning: Private methods cannot be final as they are never overridden by other classes in ...
 A::myPrivate A::myPrivate
 A::myPrivate A::myPrivate
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 </code> </code>
  
-The final keyword when applied to a private method should have no significance.+The final keyword when applied to a private method should have no significance. In most cases, a correct approach is to use ''final protected'' modifiers in a function where overriding is not desired.
  
-**Open issue**: Applying final to a private method could issue a compiler warning to warn the user that it doesn't have an effect. +**NOTE:** Due to how common the usage of ''<nowiki>final private function __construct</nowiki>'' is and given that the same results cannot be achieved with a ''protected'' visibility, an exception to this rule is made for constructors. With this exception, they are the only case where a child class can't override a ''final private'' method.
  
 ===== Backward Incompatible Changes ===== ===== Backward Incompatible Changes =====
  
-There are no BC breaking changes.+The new compiler warning:
  
-NOTE: The construction ''final private function'' is used for instance to restrict the usage of constructors and cloning of child classes. +<code> 
-A correct approach to attain a similar effect would be ''final protected function''.+Warning: Private methods cannot be final as they are never overridden by other classes in ... 
 +</code>
  
-If the optional compiler warning is implemented this change would cause some existing applications to start issuing that warning.+Will start appearing in some code bases where both modifiers ''final'' and ''private'' are used. However, given that an exception is made for the most common case ''final private function __construct'', I believe the warning is useful to let users know about this change.
  
 ===== Proposed PHP Version(s) =====  ===== Proposed PHP Version(s) ===== 
  
 PHP 8.0 PHP 8.0
- 
-===== Open Issues ===== 
- 
-  * Producing a compiler warning when ''final private function'' is used. 
  
 ===== Unaffected PHP Functionality ===== ===== Unaffected PHP Functionality =====
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 The inheritance rules for visible methods remains unaffected, including when these are static or declared on a trait. The inheritance rules for visible methods remains unaffected, including when these are static or declared on a trait.
  
-===== Proposed Voting Choices =====+===== Vote ===== 
 + 
 +Voting started 2020-06-15 and ends 2020-06-29.
  
-2/3 majority+<doodle title="Remove inappropriate inheritance signature checks on private methods" auth="pmmaga" voteType="single" closed="true"> 
 +   * Yes 
 +   * No 
 +</doodle>
  
 ===== Patches and Tests ===== ===== Patches and Tests =====
rfc/inheritance_private_methods.1587138296.txt.gz · Last modified: 2020/04/17 15:44 by pmmaga

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