======================
Rule ``static_lambda``
======================

Lambdas not (indirectly) referencing ``$this`` must be declared ``static``.

Warning
-------

Using this rule is risky
~~~~~~~~~~~~~~~~~~~~~~~~

Risky when using ``->bindTo`` on lambdas without referencing to ``$this``.

Examples
--------

Example #1
~~~~~~~~~~

.. code-block:: diff

   --- Original
   +++ New
    <?php
   -$a = function () use ($b)
   +$a = static function () use ($b)
    {   echo $b;
    };

Rule sets
---------

The rule is part of the following rule set:

- `@PhpCsFixer:risky <./../../ruleSets/PhpCsFixerRisky.rst>`_

References
----------

- Fixer class: `PhpCsFixer\\Fixer\\FunctionNotation\\StaticLambdaFixer <./../../../src/Fixer/FunctionNotation/StaticLambdaFixer.php>`_
- Test class: `PhpCsFixer\\Tests\\Fixer\\FunctionNotation\\StaticLambdaFixerTest <./../../../tests/Fixer/FunctionNotation/StaticLambdaFixerTest.php>`_

The test class defines officially supported behaviour. Each test case is a part of our backward compatibility promise.