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--- rfc:argument_unpacking [2013/09/23 19:38] – make the example for multiple ... and mixing a bit less contrived nikic
+++ rfc:argument_unpacking [2014/01/11 12:12] – -> Implemented nikic
@@ Line 2: / Line 2: @@
   * Date: 2013-08-30
   * Author: Nikita Popov <nikic@php.net>
-  * Status: Under Discussion
+  * Status: Implemented (in PHP 5.6)
-  * Proposed for: PHP 5.6
+  * Patch: https://github.com/php/php-src/pull/477
-  * Patch: https://github.com/nikic/php-src/compare/variadics...splat
   * Mailing list discussion: http://markmail.org/message/dxae5ybjldg6pftp
@@ Line 94: / Line 93: @@
 </code>
-By-reference passing will not work if the unpacked entity is a Traversable. Instead an ''E_STRICT'' level error is thrown and the argument is passed by-value instead:
+By-reference passing will not work if the unpacked entity is a Traversable. Instead an ''E_WARNING'' level error is thrown and the argument is passed by-value instead:
 <code php>
 test(...new ArrayIterator([1, 2, 3, 4, 5]));
-// Strict standards: Cannot pass by-reference argument 3 of test() by unpacking a Traversable, passing by-value instead
+// Warning: Cannot pass by-reference argument 3 of test() by unpacking a Traversable, passing by-value instead
 </code>
@@ Line 105: / Line 104: @@
   * It's not possible to determine the number of elements in a Traversable ahead of time. As such we can not know whether unpacking the Traversable will or will not hit a by-reference argument.
   * It's not possible to determine if a Traversable has support for by-reference iteration or if it will trigger an error if this is requested.
+==== String keys ====
+In order to ensure forward-compatibility with [[rfc:named_params|named arguments]] the unpacking operator does not support string keys. If a string key is encountered during unpacking a recoverable error is thrown. If the error is ignored using a custom error handler, no further arguments will be unpacked but the call still happens.
 ===== Backward Compatibility =====
@@ Line 210: / Line 213: @@
     }
 }
+</code>
+==== Normal arguments after unpacked arguments ====
+Some people also had doubts regarding the usefulness of allowing ''%%foo(...$args, $arg)%%'' calls, where a normal argument follows after an unpacked argument.
+One use-case for this pattern are the variants of ''array_diff'' and ''array_intersect'' which accept callback functions as the **last** one or two arguments:
+<code php>
+array_udiff(...$arrays, $valueCmpFunction);
+array_udiff_uassoc(...$arrays, $valueCmpFunction, $keyCmpFunction);
+</code>
+While this kind of API was undoubtedly a bad choice in the first place, I see little reason not to support calls to them.
+Another use case is appending one additional argument to a variadic argument list. For example, the following snippet adds an additional ''LIMIT'' parameter to an existing query:
+<code php>
+$this->query($query . ' LIMIT ?', ...$params, $limit);
 </code>
 ===== Patch =====
-The diff can be found here: https://github.com/nikic/php-src/compare/variadics...splat
+The patch for this features is available as a PR: https://github.com/php/php-src/pull/477
+===== Vote =====
+As this is a language change a two third majority is required.
+Voting started 2013-12-21 and ended 2014-01-11.
-The patch is based off the variadics implementation, but can also be implemented without it.
+<doodle title="Implement argument unpacking in PHP 5.6?" auth="nikic" voteType="single" closed="true">
+   * Yes
+   * No
+</doodle>
 ===== Support in other languages =====

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