From 7e378e46ef9fd12ecf28398e164d446a9cb8655b Mon Sep 17 00:00:00 2001
From: Chris Wright <daverandom@php.net>
Date: Tue, 15 Apr 2014 09:46:11 +0000
Subject: [PATCH] Improved information on behaviour of bitwise operators on
 string operands

git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@333319 c90b9560-bf6c-de11-be94-00142212c4b1
---
 language/operators.xml | 31 ++++++++++++++++++++++++-------
 1 file changed, 24 insertions(+), 7 deletions(-)

diff --git a/language/operators.xml b/language/operators.xml
index 242b9184f9..9f2100661e 100644
--- a/language/operators.xml
+++ b/language/operators.xml
@@ -611,9 +611,22 @@ $o = &new C;
     then the equivalency.
    </para>
    <para>
-    Be aware of data type conversions. If both the left-hand and
-    right-hand parameters are strings, the bitwise operator will
-    operate on the characters' ASCII values.
+    If both operands for the <literal>&amp;</literal>, <literal>|</literal> and
+    <literal>^</literal> operators are strings, then the operation will be
+    performed on the ASCII values of the characters that make up the strings and
+    the result will be a string. In all other cases, both operands will be
+    <link linkend="language.types.integer.casting">converted to integers</link>
+    and the result will be an integer.
+   </para>
+   <para>
+    If the operand for the <literal>~</literal> operator is a string, the
+    operation will be performed on the ASCII values of the characters that make
+    up the string and the result will be a string, otherwise the operand and the
+    result will be treated as integers.
+   </para>
+   <para>
+    Both operands and the result for the <literal>&lt;&lt;</literal> and
+    <literal>&gt;&gt;</literal> operators are always treated as integers.
    </para>
    <para>
     <informalexample>
@@ -1165,10 +1178,14 @@ Expression: 0 = -4 << 62
    </para>
    <warning>
     <para>
-     Don't right shift for more than 32 bits on 32 bits systems.
-     Don't left shift in case it results to number longer than 32 bits.
-     Use functions from the gmp extension for bitwise manipulation on
-     numbers beyond PHP_INT_MAX.
+     Shifting integers by values greater than or equal to the system long
+     integer width results in undefined behavior. In other words, don't shift
+     more than 31 bits on a 32-bit system, and don't shift more than 63 bits on
+     a 64-bit system.
+    </para>
+    <para>
+     Use functions from the <link linkend="book.gmp">gmp</link> extension for
+     bitwise manipulation on numbers beyond <literal>PHP_INT_MAX</literal>.
     </para>
    </warning>
    <para>