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--- rfc:hashkey [2014/10/22 13:48] – krakjoe
+++ rfc:hashkey [2014/10/22 17:57] – krakjoe
@@ Line 1: / Line 1: @@
-====== PHP RFC: __hashKey magic method ======
+====== PHP RFC: __toKey magic method ======
   * Version: 0.9
   * Date: 2014-10-22
@@ Line 7: / Line 7: @@
 ===== Proposal =====
-A new magic __hashKey method, expected to return a scalar suitable for use as a HashTable key:
+A new magic toKey method, to resolve the problem of not being able to use Objects as array keys.
 <code php>
+<?php
 class Foo {
-    public function __hashKey() {
+    public function __toKey() {
-        return __CLASS__;
+        return "Foo";
     }
 }
@@ Line 22: / Line 23: @@
 </code>
+Inheritance shall work as any other magic method:
+<code php>
+<?php
+class Foo {
+    public function __toKey() {
+        return "Foo";
+    }
+}
+class Bar extends Foo {
+    /* shall use Foo::__toKey unless Bar::__toKey is implemented */
+}
+$bar = new Bar();
+$test = [
+    $bar => true
+];
+</code>
+Returning a non-scalar shall fail as it did before:
+<code php>
+<?php
+class Foo {
+    public function __toKey() {
+        return [];
+    }
+}
+$foo = new Foo();
+$test = [
+    $foo => true
+];
+</code>
+Shall yield:
+<code php>
+Warning: Illegal offset type in %s on line %d
+</code>
+The current behaviour of __toString is unchanged.
 ===== Proposed PHP Version(s) =====