enable_language
---------------

Enable languages (CXX/C/OBJC/OBJCXX/Fortran/etc)

.. code-block:: cmake

  enable_language(<lang>... [OPTIONAL])

Enables support for the named languages in CMake.  This is the same as
the :command:`project` command but does not create any of the extra
variables that are created by the :command:`project` command.

.. include:: include/SUPPORTED_LANGUAGES.rst

The following restrictions apply to where ``enable_language()`` may be called:

* It must not be called before the first call to :command:`project`.
  See policy :policy:`CMP0165`.
* It must be called such that the command executes before any targets that
  use the language directly for compiling sources or indirectly through link
  dependencies.

.. note::
  Further restrictions apply if policy :policy:`CMP0220` is not set
  to ``NEW``.  See the policy documentation for details.

The ``OPTIONAL`` keyword is a placeholder for future implementation and
does not currently work. Instead you can use the :module:`CheckLanguage`
module to verify support before enabling.