.. index:: py::builtins::len

.. _doxycast_pypp_namespacepy_1_1builtins_1a0828e137f0c40a60875b0acfc6245b3f:

.. _py-builtins-len:

*py::builtins::*\ len
=====================

.. code-block:: cpp

     constexpr auto len(const type& container) -> decltype(container.size());

Returns the size of a container.

.. note::

     This function doesn't return ``sizeof(container)``, it returns
     ``container.size()``.

.. tip::

     Equivalent to::

         container.size();


Return value
------------

The size of a container.


Complexity
----------

Constant.


Example
-------

.. code-block::

     #include <pypp/builtins/list.hpp>
     #include <pypp/builtins/print.hpp>

     int main()
     {
         py::print(py::len(py::list<int>({4, 5, 3, 2, 8, 9, 0})));
     }

**Output**:

.. code-block:: text

     7