.. SPDX-FileCopyrightText: 2024 The IceTray Contributors
..
.. SPDX-License-Identifier: BSD-2-Clause

.. highlight:: cpp

Use nullptr instead of 0 and NULL
---------------------------------

Neither ``0`` nor ``NULL`` are by default of type pointer. Both will be
interpreted as pointers if used in such a way, but the usage of ``0`` and
``NULL`` can cause problems in some cases.

Example::

    void f(int);        // three versions of a function f
    void f(bool);
    void f(void*);

    f(0);               // call of f(int), not f(void*)
    f(NULL);            // might cause compilation error,
                        // or calls f(int)
    f(nullptr);         // calls f(void*)


You might also run into problems when you use templates. ``0`` and ``NULL``
will always be interpreted as ``int`` when a respective template is
instantiated. ``nullptr`` on the other hand will always be interpreted as a
pointer.

Also, try to avoid overloading with ``int`` and ``pointers``, since some
developers might still use ``0`` and ``NULL`` as pointers, which will cause
problems when you overload functions in that way.