Value concepts
==============

.. contents:: Table of Contents
    :local:


.. _concept-Value:

Value
-----

Let `Val` be a type that models :ref:`Value (details) <concept-details-Value>`.

Then `Val` also models :ref:`SemiregularValue <concept-SemiregularValue>`

.. _concept-Value-expressions:
.. rubric:: Expressions

Let `Val` inherit all valid expressions defined for :ref:`SemiregularValue <concept-SemiregularValue-expressions>`.


.. _concept-SemiregularValue:

SemiregularValue
----------------

Let `SemiregVal` be a type that models :ref:`SemiregularValue (details) <concept-details-SemiregularValue>`.

Then `SemiregVal` also models : :ref:`Semiregular (fundamentals) <concept-fundamentals-object-Semiregular>`.

.. _concept-SemiregularValue-expressions:
.. rubric:: Expressions

Let : 
    - ``val`` be an instance of `SemiregVal`.
    - ``val_cpy`` be an instance of `SemiregVal`.
    - ``cval`` be an instance of `const SemiregVal`.

Then we have the following valid expressions :

+-------------------------+--------------------+---------------+----------------+---------------------------------------------------+
|       Expression        |    Return type     | Pre-condition | Post-condition |                    Description                    |
+=========================+====================+===============+================+===================================================+
| ``val()``               | `SemiregVal`       | none          | none           | Constructs a value ``val`` of type `SemiregVal`   |
+-------------------------+--------------------+---------------+----------------+---------------------------------------------------+
| ``cval()``              | `const SemiregVal` | none          | none           | Constructs a value ``cval`` of type `SemiregVal`  |
+-------------------------+--------------------+---------------+----------------+---------------------------------------------------+
| ``val_cpy(val)``        | `SemiregVal`       | none          | none           | Copy-constructs a value ``val_cpy`` from ``val``  |
+-------------------------+--------------------+---------------+----------------+---------------------------------------------------+
| ``val_cpy(cval)``       | `SemiregVal`       | none          | none           | Copy-constructs a value ``val_cpy`` from ``cval`` |
+-------------------------+--------------------+---------------+----------------+---------------------------------------------------+
| ``val_cpy(move(val))``  | `SemiregVal`       | none          | none           | Move-constructs a value ``val_cpy`` from ``val``  |
+-------------------------+--------------------+---------------+----------------+---------------------------------------------------+
| ``val_cpy = val``       | `SemiregVal&`      | none          | none           | Assign ``val`` to ``val_cpy``                     |
+-------------------------+--------------------+---------------+----------------+---------------------------------------------------+
| ``val_cpy = cval``      | `SemiregVal&`      | none          | none           | Assign ``cval`` to ``val_cpy``                    |
+-------------------------+--------------------+---------------+----------------+---------------------------------------------------+
| ``val_cpy = move(val)`` | `SemiregVal&`      | none          | none           | Move-assign ``val`` to ``val_cpy``                |
+-------------------------+--------------------+---------------+----------------+---------------------------------------------------+


.. _concept-RegularValue:

RegularValue
------------

Let `RegVal` be a type that models :ref:`RegularValue (details) <concept-details-RegularValue>`.

Let `RegVal` also models :ref:`SemiregularValue <concept-SemiregularValue>` and :ref:`Regular (fundamentals) <concept-fundamentals-object-Regular>`.

.. _concept-RegularValue-expressions:
.. rubric:: Expressions

Let `RegVal` inherit all valid expressions defined for :ref:`SemiregularValue <concept-SemiregularValue-expressions>`.

Let : 
    - ``lhs`` be an instance of `const RegVal`.
    - ``rhs`` be an instance of `const RegVal`.

Then we have the following valid expressions :

+----------------+-------------+---------------+----------------+-----------------------------------------+
|   Expression   | Return type | Pre-condition | Post-condition |               Description               |
+================+=============+===============+================+=========================================+
| ``lhs == rhs`` | `bool`      | none          | none           | Compare wether two values are equal     |
+----------------+-------------+---------------+----------------+-----------------------------------------+
| ``lhs != rhs`` | `bool`      | none          | none           | Compare wether two values are different |
+----------------+-------------+---------------+----------------+-----------------------------------------+
| ``rhs == rhs`` | `bool`      | none          | none           | Compare wether two values are equal     |
+----------------+-------------+---------------+----------------+-----------------------------------------+
| ``rhs != rhs`` | `bool`      | none          | none           | Compare wether two values are different |
+----------------+-------------+---------------+----------------+-----------------------------------------+


.. _concept-StrictTotallyOrderedRegularValue:

StrictTotallyOrderedRegularValue
--------------------------------

Let `STORegVal` be a type that models :ref:`StrictTotallyOrderedRegularValue (details) <concept-details-StrictTotallyOrderedRegularValue>`.

Let `STORegVal` also models :ref:`RegularValue <concept-RegularValue>` and :ref:`StrictTotallyOrdered (fundamentals) <concept-fundamentals-comparison-StrictTotallyOrdered>`.

.. _concept-StrictTotallyOrderedRegularValue-expressions:
.. rubric:: Expressions

Let `STORegVal` inherit all valid expressions defined for :ref:`RegularValue <concept-RegularValue-expressions>`.

Let : 
    - ``lhs`` be an instance of `const STORegVal`.
    - ``rhs`` be an instance of `const STORegVal`.

Then we have the following valid expressions :

+----------------+-------------+---------------+----------------+---------------------------------+
|   Expression   | Return type | Pre-condition | Post-condition |           Description           |
+================+=============+===============+================+=================================+
| ``lhs < rhs``  | `bool`      | none          | none           | Compare order of the two values |
+----------------+-------------+---------------+----------------+---------------------------------+
| ``lhs > rhs``  | `bool`      | none          | none           | Compare order of the two values |
+----------------+-------------+---------------+----------------+---------------------------------+
| ``lhs <= rhs`` | `bool`      | none          | none           | Compare order of the two values |
+----------------+-------------+---------------+----------------+---------------------------------+
| ``lhs >= rhs`` | `bool`      | none          | none           | Compare order of the two values |
+----------------+-------------+---------------+----------------+---------------------------------+