Generic types
=====================

You can use ``dishka`` with ``TypeVars`` and ``Generic``-classes.

.. note::

    Though generics are supported, there are some limitations:

    * You cannot use ``TypeVar`` bounded to a ``Generic`` type.
    * ``Generic``-decorators are only applied to concrete factories or factories with more narrow ``TypeVars``.

Creating objects with @provide
************************************

You can create generic factories, use ``type[T]`` to access resolved value of ``TypeVar``. ``TypeVar`` can have bound or constraints, which are checked.
For example, here we have a factory providing instances of generic class ``A``. Note that ``A[int]`` and ``A[bool]`` are different types and cached separately.

.. literalinclude:: ./generics_examples/provide.py

Decorating objects with @decorate
***************************************

You can also make ``Generic`` decorator. Here it is used to decorate any type.

.. literalinclude:: ./generics_examples/decorate.py