.. _State_Constructors:

************
Constructors
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The :ref:`State` class come with different constructors.
Besides the :ref:`State_Default_Constructors`, an instance can be initialized using a `std::vector<IntType> <https://en.cppreference.com/w/cpp/container/vector>`_ in various ways, see :ref:`State_Vector_Constructors`, or using :ref:`State_Copy_Constructors`.
The :ref:`Basis<Basis_General>` requires more complex constructors, :ref:`State_Index_Constructors`, where the **index** is defined by the usual integer counting with basis :math:`Q`.
The constructors initialize an instance that refers to a given **index**  within a range defined by **start** and **end**:

.. math::
    :name: eq:state_constructors_integer_counting

    \textbf{index} = \sum_{i=\textbf{start}}^{\textbf{end-1}} \quad \sigma_i \cdot\textbf{Q}^{i-\textbf{start}} \, .
	
More details can be found in :ref:`State_Functions`.


.. toctree::
    :maxdepth: 1
 
    Constructors/Default_Constructors.rst
    Constructors/Vector_Constructors.rst
    Constructors/InitializerList_Constructors.rst
    Constructors/State_Constructors.rst
    Constructors/Index_Constructors.rst