Description:
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The documentation at http://php.net/manual/en/language.types.string.php states 
that "string can be as large as 2GB".

Now 2GB means 2*1024^3 = 2147483648 bytes.

The documentation is misleading, because strings start to misbehave once they get 
as large as 2147483647 bytes, and not 2147483648 bytes.

Yes I know, it's just a 1 byte difference, but it makes a difference between code 
that works and code that breaks.

Test script:
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error_reporting(E_STRICT|E_ALL);
ini_set('memory_limit', '-1');

$gb = 1024 * 1024 * 1024;
$str = str_repeat('a', 2 * $gb);
echo $str[0]; // Notice: Uninitialized string offset: 0 

Expected result:
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The test script should output the string "a", since 
http://php.net/manual/en/language.types.string.php specifically claims that 
strings can be as large as 2147483648 bytes.

Alternatively, we should re-word the documentation: Strings can be as large as 
2147483647 bytes. Failure to adhere to do so would result in undefined behavior 
(for example, strlen etc).

Actual result:
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Notice: Uninitialized string offset: 0