Adding upstream version 0.19.0.upstream/0.19.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

27 files changed, 3656 insertions, 0 deletions

diff --git a/doc/conf.py b/doc/conf.py
new file mode 100644
index 0000000..594d322
--- /dev/null
+++ b/doc/conf.py
@@ -0,0 +1,271 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+#
+# ixion documentation build configuration file, created by
+# sphinx-quickstart on Tue Sep 22 20:54:14 2015.
+#
+# This file is execfile()d with the current directory set to its
+# containing dir.
+#
+# Note that not all possible configuration values are present in this
+# autogenerated file.
+#
+# All configuration values have a default; values that are commented out
+# serve to show the default.
+
+import sys
+import os
+import subprocess
+
+rtd_build = os.environ.get('READTHEDOCS', None) == 'True'
+
+if rtd_build:
+    subprocess.call("doxygen --version; doxygen doxygen.conf", shell=True)
+
+# If extensions (or modules to document with autodoc) are in another directory,
+# add these directories to sys.path here. If the directory is relative to the
+# documentation root, use os.path.abspath to make it absolute, like shown here.
+#sys.path.insert(0, os.path.abspath('.'))
+
+# -- General configuration ------------------------------------------------
+
+# If your documentation needs a minimal Sphinx version, state it here.
+#needs_sphinx = '1.0'
+
+# Add any Sphinx extension module names here, as strings. They can be
+# extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
+# ones.
+extensions = ['breathe']
+
+# Add any paths that contain templates here, relative to this directory.
+templates_path = ['_templates']
+
+# The suffix of source filenames.
+source_suffix = '.rst'
+
+# The encoding of source files.
+#source_encoding = 'utf-8-sig'
+
+# The master toctree document.
+master_doc = 'index'
+
+# General information about the project.
+project = 'Ixion'
+copyright = '2021, Kohei Yoshida'
+
+# The version info for the project you're documenting, acts as replacement for
+# |version| and |release|, also used in various other places throughout the
+# built documents.
+#
+# The short X.Y version.
+version = '0.19'
+# The full version, including alpha/beta/rc tags.
+release = '0.19.0'
+
+# The language for content autogenerated by Sphinx. Refer to documentation
+# for a list of supported languages.
+#language = None
+
+# There are two options for replacing |today|: either, you set today to some
+# non-false value, then it is used:
+#today = ''
+# Else, today_fmt is used as the format for a strftime call.
+#today_fmt = '%B %d, %Y'
+
+# List of patterns, relative to source directory, that match files and
+# directories to ignore when looking for source files.
+exclude_patterns = ['_build']
+
+# The reST default role (used for this markup: `text`) to use for all
+# documents.
+#default_role = None
+
+# If true, '()' will be appended to :func: etc. cross-reference text.
+#add_function_parentheses = True
+
+# If true, the current module name will be prepended to all description
+# unit titles (such as .. function::).
+#add_module_names = True
+
+# If true, sectionauthor and moduleauthor directives will be shown in the
+# output. They are ignored by default.
+#show_authors = False
+
+# The name of the Pygments (syntax highlighting) style to use.
+pygments_style = 'sphinx'
+
+# A list of ignored prefixes for module index sorting.
+#modindex_common_prefix = []
+
+# If true, keep warnings as "system message" paragraphs in the built documents.
+#keep_warnings = False
+
+
+# -- Options for HTML output ----------------------------------------------
+
+# The theme to use for HTML and HTML Help pages.  See the documentation for
+# a list of builtin themes.
+html_theme = 'sphinx_rtd_theme'
+
+# Theme options are theme-specific and customize the look and feel of a theme
+# further.  For a list of options available for each theme, see the
+# documentation.
+html_theme_options = {}
+
+# Add any paths that contain custom themes here, relative to this directory.
+#html_theme_path = []
+
+# The name for this set of Sphinx documents.  If None, it defaults to
+# "<project> v<release> documentation".
+#html_title = None
+
+# A shorter title for the navigation bar.  Default is the same as html_title.
+#html_short_title = None
+
+# The name of an image file (relative to this directory) to place at the top
+# of the sidebar.
+#html_logo = None
+
+# The name of an image file (within the static path) to use as favicon of the
+# docs.  This file should be a Windows icon file (.ico) being 16x16 or 32x32
+# pixels large.
+#html_favicon = None
+
+# Add any paths that contain custom static files (such as style sheets) here,
+# relative to this directory. They are copied after the builtin static files,
+# so a file named "default.css" will overwrite the builtin "default.css".
+html_static_path = ['_static']
+
+# Add any extra paths that contain custom files (such as robots.txt or
+# .htaccess) here, relative to this directory. These files are copied
+# directly to the root of the documentation.
+#html_extra_path = []
+
+# If not '', a 'Last updated on:' timestamp is inserted at every page bottom,
+# using the given strftime format.
+#html_last_updated_fmt = '%b %d, %Y'
+
+# If true, SmartyPants will be used to convert quotes and dashes to
+# typographically correct entities.
+#html_use_smartypants = True
+
+# Custom sidebar templates, maps document names to template names.
+#html_sidebars = {}
+
+# Additional templates that should be rendered to pages, maps page names to
+# template names.
+#html_additional_pages = {}
+
+# If false, no module index is generated.
+#html_domain_indices = True
+
+# If false, no index is generated.
+#html_use_index = True
+
+# If true, the index is split into individual pages for each letter.
+#html_split_index = False
+
+# If true, links to the reST sources are added to the pages.
+#html_show_sourcelink = True
+
+# If true, "Created using Sphinx" is shown in the HTML footer. Default is True.
+#html_show_sphinx = True
+
+# If true, "(C) Copyright ..." is shown in the HTML footer. Default is True.
+#html_show_copyright = True
+
+# If true, an OpenSearch description file will be output, and all pages will
+# contain a <link> tag referring to it.  The value of this option must be the
+# base URL from which the finished HTML is served.
+#html_use_opensearch = ''
+
+# This is the file name suffix for HTML files (e.g. ".xhtml").
+#html_file_suffix = None
+
+# Output file base name for HTML help builder.
+htmlhelp_basename = 'ixiondoc'
+
+
+# -- Options for LaTeX output ---------------------------------------------
+
+latex_elements = {
+# The paper size ('letterpaper' or 'a4paper').
+#'papersize': 'letterpaper',
+
+# The font size ('10pt', '11pt' or '12pt').
+#'pointsize': '10pt',
+
+# Additional stuff for the LaTeX preamble.
+#'preamble': '',
+}
+
+# Grouping the document tree into LaTeX files. List of tuples
+# (source start file, target name, title,
+#  author, documentclass [howto, manual, or own class]).
+latex_documents = [
+  ('index', 'ixion.tex', 'Ixion Documentation',
+   'Kohei Yoshida', 'manual'),
+]
+
+# The name of an image file (relative to this directory) to place at the top of
+# the title page.
+#latex_logo = None
+
+# For "manual" documents, if this is true, then toplevel headings are parts,
+# not chapters.
+#latex_use_parts = False
+
+# If true, show page references after internal links.
+#latex_show_pagerefs = False
+
+# If true, show URL addresses after external links.
+#latex_show_urls = False
+
+# Documents to append as an appendix to all manuals.
+#latex_appendices = []
+
+# If false, no module index is generated.
+#latex_domain_indices = True
+
+
+# -- Options for manual page output ---------------------------------------
+
+# One entry per manual page. List of tuples
+# (source start file, name, description, authors, manual section).
+man_pages = [
+    ('index', 'ixion', 'Ixion Documentation',
+     ['Kohei Yoshida'], 1)
+]
+
+# If true, show URL addresses after external links.
+#man_show_urls = False
+
+
+# -- Options for Texinfo output -------------------------------------------
+
+# Grouping the document tree into Texinfo files. List of tuples
+# (source start file, target name, title, author,
+#  dir menu entry, description, category)
+texinfo_documents = [
+  ('index', 'ixion', 'Ixion Documentation',
+   'Kohei Yoshida', 'Ixion', 'One line description of project.',
+   'Miscellaneous'),
+]
+
+# Documents to append as an appendix to all manuals.
+#texinfo_appendices = []
+
+# If false, no module index is generated.
+#texinfo_domain_indices = True
+
+# How to display URL addresses: 'footnote', 'no', or 'inline'.
+#texinfo_show_urls = 'footnote'
+
+# If true, do not generate a @detailmenu in the "Top" node's menu.
+#texinfo_no_detailmenu = False
+
+breathe_projects = {"ixion": "./_doxygen/xml"}
+
+breathe_default_project = "ixion"
+
+breathe_default_members = ('members', 'undoc-members')
diff --git a/doc/cpp/data_store/cell_access.rst b/doc/cpp/data_store/cell_access.rst
new file mode 100644
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--- /dev/null
+++ b/doc/cpp/data_store/cell_access.rst
@@ -0,0 +1,79 @@
+
+.. highlight:: cpp
+
+Cell Access
+===========
+
+Examples
+--------
+
+You can obtain a :cpp:class:`~ixion::cell_access` instance either from
+:cpp:class:`~ixion::model_context` or :cpp:class:`~ixion::document` class.
+
+Here is an example of how to obtain it from a :cpp:class:`~ixion::model_context` instance::
+
+    ixion::model_context cxt;
+    cxt.append_sheet("Sheet");
+
+    // fill this model context
+
+    ixion::abs_address_t A1(0, 0, 0);
+    ixion::cell_access ca = cxt.get_cell_access(A1);
+
+
+Here is an example of how to obtain it from a :cpp:class:`~ixion::document` instance::
+
+    ixion::document doc;
+    doc.append_sheet("Sheet");
+
+    // fill this document
+
+    ixion::cell_access ca = doc.get_cell_access("A1");
+
+
+Once you have your :cpp:class:`~ixion::cell_access` instance, you can, for instance,
+print the value of the cell as follows::
+
+    switch (ca.get_value_type())
+    {
+        case ixion::cell_value_t::numeric:
+        {
+            double v = ca.get_numeric_value();
+            cout << "numeric value: " << v << endl;
+            break;
+        }
+        case ixion::cell_value_t::string:
+        {
+            std::string_view s = ca.get_string_value();
+            cout << "string value: " << s << endl;
+            break;
+        }
+        case ixion::cell_value_t::boolean:
+        {
+            cout << "boolean value: " << ca.get_boolean_value() << endl;
+            break;
+        }
+        case ixion::cell_value_t::error:
+        {
+            ixion::formula_error_t err = ca.get_error_value();
+            cout << "error value: " << ixion::get_formula_error_name(err) << endl;
+            break;
+        }
+        case ixion::cell_value_t::empty:
+        {
+            cout << "empty cell" << endl;
+            break;
+        }
+        default:
+            cout << "???" << endl;
+    }
+
+The complete source code of this example is avaiable
+`here <https://gitlab.com/ixion/ixion/-/blob/master/doc_example/section_examples/cell_access.cpp>`_.
+
+
+API Reference
+-------------
+
+.. doxygenclass:: ixion::cell_access
+   :members:
diff --git a/doc/cpp/data_store/dirty_cell_tracker.rst b/doc/cpp/data_store/dirty_cell_tracker.rst
new file mode 100644
index 0000000..bf4e20a
--- /dev/null
+++ b/doc/cpp/data_store/dirty_cell_tracker.rst
@@ -0,0 +1,8 @@
+
+.. highlight:: cpp
+
+Dirty Cell Tracker
+==================
+
+.. doxygenclass:: ixion::dirty_cell_tracker
+   :members:
diff --git a/doc/cpp/data_store/document.rst b/doc/cpp/data_store/document.rst
new file mode 100644
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--- /dev/null
+++ b/doc/cpp/data_store/document.rst
@@ -0,0 +1,18 @@
+
+.. highlight:: cpp
+
+Document
+========
+
+Examples
+--------
+
+Refer to the :ref:`quickstart-document` section for code examples on how to
+use the :cpp:class:`~ixion::document` class.
+
+API Reference
+-------------
+
+.. doxygenclass:: ixion::document
+   :members:
+
diff --git a/doc/cpp/data_store/index.rst b/doc/cpp/data_store/index.rst
new file mode 100644
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--- /dev/null
+++ b/doc/cpp/data_store/index.rst
@@ -0,0 +1,13 @@
+
+Data Store
+==========
+
+.. toctree::
+   :maxdepth: 2
+
+   model_context.rst
+   document.rst
+   cell_access.rst
+   dirty_cell_tracker.rst
+   types.rst
+
diff --git a/doc/cpp/data_store/model_context.rst b/doc/cpp/data_store/model_context.rst
new file mode 100644
index 0000000..d0b131d
--- /dev/null
+++ b/doc/cpp/data_store/model_context.rst
@@ -0,0 +1,24 @@
+
+.. highlight:: cpp
+
+Model Context
+=============
+
+Examples
+--------
+
+Refer to the :ref:`quickstart-model-context` section for code examples on how
+to use the :cpp:class:`~ixion::model_context` class.
+
+API Reference
+-------------
+
+.. doxygenclass:: ixion::model_context
+   :members:
+
+.. doxygenstruct:: ixion::config
+   :members:
+
+.. doxygenclass:: ixion::model_iterator
+   :members:
+
diff --git a/doc/cpp/data_store/types.rst b/doc/cpp/data_store/types.rst
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+++ b/doc/cpp/data_store/types.rst
@@ -0,0 +1,89 @@
+
+Types
+=====
+
+Macros
+------
+
+.. doxygendefine:: IXION_ASCII
+
+
+Primitive Types
+---------------
+
+.. doxygenenum:: ixion::celltype_t
+.. doxygenenum:: ixion::cell_value_t
+.. doxygenenum:: ixion::value_t
+.. doxygenenum:: ixion::table_area_t
+.. doxygenenum:: ixion::formula_name_resolver_t
+.. doxygenenum:: ixion::formula_error_t
+.. doxygenenum:: ixion::formula_result_wait_policy_t
+.. doxygenenum:: ixion::formula_event_t
+.. doxygenenum:: ixion::rc_direction_t
+
+.. doxygentypedef:: ixion::col_t
+.. doxygentypedef:: ixion::row_t
+.. doxygentypedef:: ixion::sheet_t
+.. doxygentypedef:: ixion::rc_t
+.. doxygentypedef:: ixion::string_id_t
+.. doxygentypedef:: ixion::table_areas_t
+.. doxygentypedef:: ixion::formula_tokens_t
+
+.. doxygenvariable:: ixion::empty_string_id
+.. doxygenvariable:: ixion::global_scope
+.. doxygenvariable:: ixion::invalid_sheet
+
+.. doxygenstruct:: ixion::rc_size_t
+.. doxygenstruct:: ixion::formula_group_t
+
+
+Cell Addresses
+--------------
+
+.. doxygenstruct:: ixion::address_t
+   :members:
+
+.. doxygenstruct:: ixion::rc_address_t
+   :members:
+
+.. doxygenstruct:: ixion::abs_address_t
+   :members:
+
+.. doxygenstruct:: ixion::abs_rc_address_t
+   :members:
+
+.. doxygenstruct:: ixion::range_t
+   :members:
+
+.. doxygenstruct:: ixion::abs_range_t
+   :members:
+
+.. doxygenstruct:: ixion::abs_rc_range_t
+   :members:
+
+.. doxygenstruct:: ixion::table_t
+   :members:
+
+.. doxygentypedef:: ixion::abs_address_set_t
+
+.. doxygentypedef:: ixion::abs_range_set_t
+
+.. doxygentypedef:: ixion::abs_rc_range_set_t
+
+
+Column Blocks
+-------------
+
+.. doxygentypedef:: ixion::column_block_handle
+.. doxygentypedef:: ixion::column_block_callback_t
+.. doxygenenum:: ixion::column_block_t
+
+.. doxygenstruct:: ixion::column_block_shape_t
+   :members:
+
+Utility Functions
+-----------------
+
+.. doxygenfunction:: ixion::get_formula_error_name
+
+.. doxygenfunction:: ixion::to_formula_error_type
diff --git a/doc/cpp/formula/formula_cell.rst b/doc/cpp/formula/formula_cell.rst
new file mode 100644
index 0000000..882edaf
--- /dev/null
+++ b/doc/cpp/formula/formula_cell.rst
@@ -0,0 +1,10 @@
+
+Formula Cell
+============
+
+.. doxygenclass:: ixion::formula_cell
+   :members:
+
+.. doxygenclass:: ixion::formula_result
+   :members:
+
diff --git a/doc/cpp/formula/formula_engine.rst b/doc/cpp/formula/formula_engine.rst
new file mode 100644
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--- /dev/null
+++ b/doc/cpp/formula/formula_engine.rst
@@ -0,0 +1,19 @@
+
+Formula Engine
+==============
+
+.. doxygenfunction:: ixion::parse_formula_string
+.. doxygenfunction:: ixion::print_formula_tokens
+.. doxygenfunction:: ixion::register_formula_cell
+.. doxygenfunction:: ixion::unregister_formula_cell
+.. doxygenfunction:: ixion::query_dirty_cells
+.. doxygenfunction:: ixion::query_and_sort_dirty_cells
+.. doxygenfunction:: ixion::calculate_sorted_cells
+
+
+Formula Functions
+=================
+
+.. doxygenenum:: ixion::formula_function_t
+.. doxygenfunction:: ixion::get_formula_function_name
+.. doxygenfunction:: ixion::get_formula_function_opcode
diff --git a/doc/cpp/formula/formula_name_resolver.rst b/doc/cpp/formula/formula_name_resolver.rst
new file mode 100644
index 0000000..ea9f988
--- /dev/null
+++ b/doc/cpp/formula/formula_name_resolver.rst
@@ -0,0 +1,10 @@
+
+Formula Name Resolver
+=====================
+
+.. doxygenclass:: ixion::formula_name_resolver
+   :members:
+
+.. doxygenstruct:: ixion::formula_name_t
+   :members:
+
diff --git a/doc/cpp/formula/formula_tokens.rst b/doc/cpp/formula/formula_tokens.rst
new file mode 100644
index 0000000..06d33a0
--- /dev/null
+++ b/doc/cpp/formula/formula_tokens.rst
@@ -0,0 +1,19 @@
+
+Formula Tokens
+==============
+
+.. doxygenstruct:: ixion::formula_token
+   :members:
+
+.. doxygenclass:: ixion::formula_tokens_store
+   :members:
+
+.. doxygenstruct:: ixion::named_expression_t
+   :members:
+
+Utility Functions
+-----------------
+
+.. doxygenfunction:: ixion::get_opcode_name
+
+.. doxygenfunction:: ixion::get_formula_opcode_string
diff --git a/doc/cpp/formula/index.rst b/doc/cpp/formula/index.rst
new file mode 100644
index 0000000..976405a
--- /dev/null
+++ b/doc/cpp/formula/index.rst
@@ -0,0 +1,12 @@
+
+Formula
+=======
+
+.. toctree::
+   :maxdepth: 2
+
+   formula_engine.rst
+   formula_cell.rst
+   formula_tokens.rst
+   formula_name_resolver.rst
+   types.rst
diff --git a/doc/cpp/formula/types.rst b/doc/cpp/formula/types.rst
new file mode 100644
index 0000000..9885512
--- /dev/null
+++ b/doc/cpp/formula/types.rst
@@ -0,0 +1,14 @@
+
+Types
+=====
+
+.. doxygenenum:: ixion::fopcode_t
+
+Matrix
+------
+
+.. doxygenclass:: ixion::matrix
+   :members:
+
+.. doxygenclass:: ixion::numeric_matrix
+   :members:
diff --git a/doc/cpp/index.rst b/doc/cpp/index.rst
new file mode 100644
index 0000000..65e970d
--- /dev/null
+++ b/doc/cpp/index.rst
@@ -0,0 +1,16 @@
+.. highlight:: cpp
+
+.. _index:
+
+C++ API
+=======
+
+.. toctree::
+   :maxdepth: 2
+
+   quickstart/index.rst
+   formula/index.rst
+   data_store/index.rst
+   interface/index.rst
+
+
diff --git a/doc/cpp/interface/index.rst b/doc/cpp/interface/index.rst
new file mode 100644
index 0000000..10fc539
--- /dev/null
+++ b/doc/cpp/interface/index.rst
@@ -0,0 +1,10 @@
+
+Interfaces
+==========
+
+.. doxygenclass:: ixion::iface::session_handler
+   :members:
+
+.. doxygenclass:: ixion::iface::table_handler
+   :members:
+
diff --git a/doc/cpp/quickstart/index.rst b/doc/cpp/quickstart/index.rst
new file mode 100644
index 0000000..5097e02
--- /dev/null
+++ b/doc/cpp/quickstart/index.rst
@@ -0,0 +1,13 @@
+
+.. highlight:: cpp
+
+Quickstart
+==========
+
+.. toctree::
+   :maxdepth: 1
+
+   using_model_context.rst
+   using_document.rst
+
+
diff --git a/doc/cpp/quickstart/using_document.rst b/doc/cpp/quickstart/using_document.rst
new file mode 100644
index 0000000..8c6b779
--- /dev/null
+++ b/doc/cpp/quickstart/using_document.rst
@@ -0,0 +1,143 @@
+
+.. highlight:: cpp
+
+.. _quickstart-document:
+
+Using document class
+====================
+
+In the :ref:`quickstart-model-context` section, we saw an example of how to
+set up a cell value store and run some simple calculations using the
+:cpp:class:`~ixion::model_context` class.  While that approach certainly works
+fine, one large drawback is that you do need to manually handle formula tokenization,
+formula cell registration (and un-registration), as well as to trace which cells
+have their values changed and which formula cells have been created or modified.
+This is because the :cpp:class:`~ixion::model_context` class is designed to only
+handle cell value storage, and all other operations related to formula expressions
+and formula cell (re-)calculations have to be done outside of it.
+
+Luckily, Ixion also provides a higher level document class called
+:cpp:class:`~ixion::document` which internally uses :cpp:class:`~ixion::model_context`
+and handles all the formula cell related operations internally.  This section
+provides an overview of how to use the :cpp:class:`~ixion::document` class to
+do more or less similar things we did in the :ref:`quickstart-model-context`
+section.
+
+First, we need to instantiate the :cpp:class:`~ixion::document` instance and
+insert a sheet named ``MySheet``.
+
+::
+
+    ixion::document doc;
+    doc.append_sheet("MySheet");
+
+Next, like we did in the previous section, we will insert numbers 1 through 10
+in cells A1 through A10::
+
+    for (ixion::abs_address_t pos(0, 0, 0); pos.row <= 9; ++pos.row)
+    {
+        double value = pos.row + 1.0; // Set the row position + 1 as the cell value.
+        doc.set_numeric_cell(pos, value);
+    }
+
+So far we don't see much of a difference from model_context.  Let's now insert
+string values into cells B2 and B3::
+
+    // Insert string values.
+    std::string s = "This cell contains a string value.";
+    doc.set_string_cell("B2", s);
+    doc.set_string_cell("B3", "This too contains a string value.");
+
+Here we see the first difference.  When using :cpp:class:`~ixion::document`,
+You can specify the cell position either by :cpp:struct:`~ixion::abs_address_t`
+as with :cpp:class:`~ixion::model_context`, or by a string whose value is the
+name of the cell address.  The default address syntax for the string cell address
+is "Excel A1" syntax.  You can pick a different syntax by passing a value of type
+:cpp:enum:`~ixion::formula_name_resolver_t` to the constructor.
+
+It's worth noting that, when specifying the cell position as a string value and
+the sheet name is omitted, the first sheet is implied.  You can also specify
+the sheet name explicitly as in the following::
+
+    doc.set_string_cell("MySheet!B4", "Yet another string value.");
+
+For a document with only one sheet, it makes no difference whether to include
+the sheet name or leave it out, but if you have more than one sheet, you need to
+specify the sheet name when specifying a cell position on sheets other than the
+first one.
+
+Now, let's insert a a formula into A11 to sum up values in A1:A10, and calculate
+it afterward::
+
+    doc.set_formula_cell("A11", "SUM(A1:A10)");
+    doc.calculate(0);
+
+And fetch the calculated value in A11 and see what the result is::
+
+    double value = doc.get_numeric_value("A11");
+    cout << "value of A11: " << value << endl;
+
+You should see the following output:
+
+.. code-block:: text
+
+    value of A11: 55
+
+It looks about right.  The :cpp:func:`~ixion::document::calculate` method takes one
+argument that is the number of threads to use for the calculation.  We pass 0 here to
+run the calculation using only the main thread.
+
+Now, let's re-write the formula in cell A11 to take the average of A1:A10 instead,
+run the calculation again, and check the value of A11::
+
+    // Insert a new formula to A11.
+    doc.set_formula_cell("A11", "AVERAGE(A1:A10)");
+    doc.calculate(0);
+
+    value = doc.get_numeric_value("A11");
+    cout << "value of A11: " << value << endl;
+
+The output says:
+
+.. code-block:: text
+
+    value of A11: 5.5
+
+which looks right.  Note that, unlike the previous example, there is no need to un-register
+and register cell A11 before and after the edit.
+
+Lastly, let's insert into cell A10 a new formula that contains no references to other cells.
+As this will trigger a re-calculation of cell A11, we will check the values of both A10
+and A11::
+
+    // Overwrite A10 with a formula cell with no references.
+    doc.set_formula_cell("A10", "(100+50)/2");
+    doc.calculate(0);
+
+    value = doc.get_numeric_value("A10");
+    cout << "value of A10: " << value << endl;
+
+    value = doc.get_numeric_value("A11");
+    cout << "value of A11: " << value << endl;
+
+The output will be:
+
+.. code-block:: text
+
+    value of A10: 75
+    value of A11: 12
+
+Notice once again that there is no need to do formula cell registration nor manual tracking
+of dirty formula cells.
+
+
+Conclusion
+----------
+
+In this section, we have performed the same thing we did in the :ref:`quickstart-model-context`
+section, but with much less code, and without the complexity of low-level formula expression
+tokenization, formula cell registration, or manual tracking of modified cells.  If you are
+looking to leverage the functionality of Ixion but don't want to deal with lower-level formula
+API, using the :cpp:class:`~ixion::document` class may be just the ticket.
+
+The complete source code of this example is avaiable `here <https://gitlab.com/ixion/ixion/-/blob/master/doc_example/document_simple.cpp>`_.
diff --git a/doc/cpp/quickstart/using_model_context.rst b/doc/cpp/quickstart/using_model_context.rst
new file mode 100644
index 0000000..f37bd5f
--- /dev/null
+++ b/doc/cpp/quickstart/using_model_context.rst
@@ -0,0 +1,318 @@
+
+.. highlight:: cpp
+
+.. _quickstart-model-context:
+
+Using model_context class
+=========================
+
+Create a model context instance
+-------------------------------
+
+When using ixion, the very first step is to create a :cpp:class:`~ixion::model_context`
+instance::
+
+    ixion::model_context cxt;
+
+The :cpp:class:`~ixion::model_context` class represents a document model data
+store that stores cell values spreading over one or more sheets.  At the time of construction,
+the model contains no sheets. So the obvious next step is to insert a sheet::
+
+    // First and foremost, insert a sheet.
+    cxt.append_sheet("MySheet");
+
+The :cpp:func:`~ixion::model_context::append_sheet` method will append a new sheet to
+the model.  You need to give a name when appending a sheet, and the name must be unique
+for each sheet.
+
+.. note::
+
+    Each sheet has a fixed size which cannot be changed once the :cpp:class:`~ixion::model_context`
+    object is instantiated.  The default sheet size is 1048576 rows by 16384 columns.  You can
+    specify a custom sheet size by passing a desired sheet size value to the
+    :cpp:class:`~ixion::model_context` constructor at the time of instantiation.
+
+
+Populate model context with values
+----------------------------------
+
+Now that you have your first sheet inserted, let's put in some numeric values.  In this example,
+we'll insert into A1:A10 their respective row positions.  To insert a numeric value, you use
+:cpp:func:`~ixion::model_context::set_numeric_cell` which takes the position of the cell as its
+first argument and the value to set as its second argument.  You need to use :cpp:class:`~ixion::abs_address_t`
+to specify a cell position.
+
+::
+
+    // Now, populate it with some numeric values in A1:A10.
+    for (ixion::abs_address_t pos(0, 0, 0); pos.row <= 9; ++pos.row)
+    {
+        double value = pos.row + 1.0; // Set the row position + 1 as the cell value.
+        cxt.set_numeric_cell(pos, value);
+    }
+
+Note that, since row and column positions are internally 0-based, we add one to emulate how the row
+positions are presented in typical spreadsheet program.
+
+Inserting a string value can be done via :cpp:func:`~ixion::model_context::set_string_cell` in one
+of two ways.  The first way is to store the value to a type that decays to ``std::string_view``, such
+as ``std::string``, char array, or string literal, and pass it to the method directly::
+
+    // Insert a string value into B2.
+    ixion::abs_address_t B2(0, 1, 1);
+    std::string s = "This cell contains a string value.";
+    cxt.set_string_cell(B2, s);
+
+    // Insert a literal string value into B3.
+    ixion::abs_address_t B3(0, 2, 1);
+    cxt.set_string_cell(B3, "This too contains a string value.");
+
+The second way is to add your string to the model_context's internal string pool first which will return its
+string ID, and pass that ID to the method::
+
+    // Insert a string value into B4 via string identifier.
+    ixion::string_id_t sid = cxt.add_string("Yet another string value.");
+    ixion::abs_address_t B4(0, 3, 1);
+    cxt.set_string_cell(B4, sid);
+
+The model_context class has two methods for inserting a string to the string pool:
+:cpp:func:`~ixion::model_context::add_string` and :cpp:func:`~ixion::model_context::append_string`.  The
+:cpp:func:`~ixion::model_context::add_string` method checks for an existing entry with the same string value
+upon each insertion attempt, and it will not insert the new value if the value already exists in the pool.
+The :cpp:func:`~ixion::model_context::append_string` method, on the other hand, does not check the pool for
+an existing value and always inserts the value.  The :cpp:func:`~ixion::model_context::append_string` method
+is appropriate if you know all your string entries ahead of time and wish to bulk-insert them.  Otherwise
+using :cpp:func:`~ixion::model_context::add_string` is appropriate in most cases.
+
+
+Insert a formula cell into model context
+----------------------------------------
+
+Inserting a formula cell requires a few extra steps.  First, you need to tokenize your formula string, and
+to do that, you need to create an instance of :cpp:class:`~ixion::formula_name_resolver`.  The
+formula_name_resolver class is responsible for resolving "names" into references, functions, and named
+expressions names.  Ixion provides multiple types of name resolvers, and you specify its type when passing
+an enum value of type :cpp:enum:`~ixion::formula_name_resolver_t` when calling its static
+:cpp:func:`ixion::formula_name_resolver::get` function.  In this example, we'll be using the Excel A1
+syntax::
+
+    // Tokenize formula string first.
+    std::unique_ptr<ixion::formula_name_resolver> resolver =
+        ixion::formula_name_resolver::get(ixion::formula_name_resolver_t::excel_a1, &cxt);
+
+You can also optionally pass a memory address of your :cpp:class:`~ixion::model_context` instance which is
+required for resolving sheet names.  You can pass a ``nullptr`` if you don't need to resolve sheet names.
+
+Next, let's create a formula string we want to tokenize.  Here, we are inserting a formula expression
+**SUM(A1:A10)** into cell A11::
+
+    ixion::abs_address_t A11(0, 10, 0);
+    ixion::formula_tokens_t tokens = ixion::parse_formula_string(cxt, A11, *resolver, "SUM(A1:A10)");
+
+To tokenize a formula string, you call the :cpp:func:`ixion::parse_formula_string` function and pass
+
+* a model_context instance
+* the position of the cell to insert the formula into,
+* a formula_name_resolver instance, and
+* the formula string to tokenize.
+
+The function will then return a sequence of tokens representing the original formula string.  Once you
+have the tokens, you can finally pass them to your model_context instance via
+:cpp:func:`~ixion::model_context::set_formula_cell`::
+
+    // Set the tokens into the model.
+    const ixion::formula_cell* cell = cxt.set_formula_cell(A11, std::move(tokens));
+
+There is a few things to note. First, you need to *move* your tokens to the method since instances of
+type :cpp:type:`ixion::formula_tokens_t` are non-copyable and only movable.  Second, the method returns
+a pointer to the formula cell instance that just got inserted into the model. We are saving it here
+to use it in the next step below.
+
+When inserting a formula cell, you need to "register" it so that the model can record its reference
+dependencies via :cpp:func:`~ixion::register_formula_cell`::
+
+    // Register this formula cell for automatic dependency tracking.
+    ixion::register_formula_cell(cxt, A11, cell);
+
+Without registering formula cells, you won't be able to determine which formula cells to re-calculate
+for given modified cells.  Here we are passing the pointer to the formula cell returned from the previous
+call.  This is optional, and you can pass a ``nullptr`` instead. But by passing it you will avoid the
+overhead of searching for the cell instance from the model.
+
+
+Calculate formula cell
+----------------------
+
+Now that we have the formula cell in, let's run our first calculation.  To calcualte formula cells, you
+need to first specify a range of modified cells in order to query for all formula cells affected by it
+either directly or indirectly, which we refer to as "dirty" formula cells.  Since this is our initial
+calculation, we can simply specify the entire sheet to be "modified" which will effectively trigger all
+formula cells::
+
+    ixion::rc_size_t sheet_size = cxt.get_sheet_size();
+    ixion::abs_range_t entire_sheet(0, 0, 0, sheet_size.row, sheet_size.column); // sheet, row, column, row span, column span
+    ixion::abs_range_set_t modified_cells{entire_sheet};
+
+We will then pass it to :cpp:func:`~ixion::query_and_sort_dirty_cells` to get a sequence of formula cell
+addresses to calculate::
+
+    // Determine formula cells that need re-calculation given the modified cells.
+    // There should be only one formula cell in this example.
+    std::vector<ixion::abs_range_t> dirty_cells = ixion::query_and_sort_dirty_cells(cxt, modified_cells);
+    cout << "number of dirty cells: " << dirty_cells.size() << endl;
+
+Since so far we only have one formula cell, this should only return one range with the size of one row and one column.  You
+will see the following output:
+
+.. code-block:: text
+
+    number of dirty cells: 1
+
+Let's inspect which cell it actually refers to::
+
+    cout << "dirty cell: " << dirty_cells[0] << endl;
+
+which will print:
+
+.. code-block:: text
+
+    dirty cell: (sheet:0; row:10; column:0)-(sheet:0; row:10; column:0)
+
+confirming that it certainly points to cell A11.  Finally, pass this to :cpp:func:`~ixion::calculate_sorted_cells`::
+
+    // Now perform calculation.
+    ixion::calculate_sorted_cells(cxt, dirty_cells, 0);
+
+to calculate cell A11.  After that, you can retrieve the result of the calculation by calling
+:cpp:func:`~ixion::model_context::get_numeric_value` for A11::
+
+    double value = cxt.get_numeric_value(A11);
+    cout << "value of A11: " << value << endl;
+
+You will see the following output:
+
+.. code-block:: text
+
+    value of A11: 55
+
+
+Modify formula cell
+-------------------
+
+Let's say you need to overwrite the formula in A11 to something else.  The steps you need to take
+are very similar to the steps for inserting a brand-new formula cell, the only difference being
+that you need to "unregister" the old formula cell before overwriting it.
+
+Let's go through this step by step.  First, create new tokens to insert::
+
+    // Insert a new formula to A11.
+    tokens = ixion::parse_formula_string(cxt, A11, *resolver, "AVERAGE(A1:A10)");
+
+This time we are inserting the formula **AVERAGE(A1:A10)** in A11 to overwrite the previous one
+**SUM(A1:A10)**.  Before inserting these tokens, first unregister the current formula cell::
+
+    // Before overwriting, make sure to UN-register the old cell.
+    ixion::unregister_formula_cell(cxt, A11);
+
+This will remove the dependency information of the old formula from the model's internal tracker.
+Once that's done, the rest is the same as inserting a new formula::
+
+    // Set and register the new formula cell.
+    cell = cxt.set_formula_cell(A11, std::move(tokens));
+    ixion::register_formula_cell(cxt, A11, cell);
+
+Let's re-calculate the new formula cell.  The re-calculation steps are also very similar to the initial
+calculation steps.  The first step is to query for all dirty formula cells.  This time, however, we don't
+query based on which formula cells are affected by modified cells, which we'll specify as none.  Instead,
+we query based on which formula cells have been modified, which in this case is A11::
+
+    // This time, we know that none of the cell values have changed, but the
+    // formula A11 is updated & needs recalculation.
+    ixion::abs_range_set_t modified_formula_cells{A11};
+    dirty_cells = ixion::query_and_sort_dirty_cells(cxt, ixion::abs_range_set_t(), &modified_formula_cells);
+    cout << "number of dirty cells: " << dirty_cells.size() << endl;
+
+As is the first calculation, you should only get one dirty cell address from the :cpp:func:`~ixion::query_and_sort_dirty_cells`
+call.  Running the above code should produce:
+
+.. code-block:: text
+
+    number of dirty cells: 1
+
+The rest should be familiar::
+
+    // Perform calculation again.
+    ixion::calculate_sorted_cells(cxt, dirty_cells, 0);
+
+    value = cxt.get_numeric_value(A11);
+    cout << "value of A11: " << value << endl;
+
+You should see the following output when finished:
+
+.. code-block:: text
+
+    value of A11: 5.5
+
+
+Formula cell with no references
+-------------------------------
+
+Next example shows a scenario where you want to overwrite a cell in A10, which
+currently stores a numeric value, with a formula cell that references no other
+cells.  Let's add the new formula cell first::
+
+    // Overwrite A10 with a formula cell with no references.
+    ixion::abs_address_t A10(0, 9, 0);
+    tokens = ixion::parse_formula_string(cxt, A10, *resolver, "(100+50)/2");
+    cxt.set_formula_cell(A10, std::move(tokens));
+
+Here, we are not registering this cell since it contains no references hence it
+does not need to be tracked by dependency tracker.  Also, since the previous
+cell in A10 is not a formula cell, there is no cell to unregister.
+
+.. warning::
+
+    Technically speaking, every formula cell that contains references to other
+    cells or contains at least one volatile function needs to be registered.
+    Since registering a formula cell that doesn't need to be registered is
+    entirely harmless (albeit a slight overhead), it's generally a good idea to
+    register every new formula cell regardless of its content.
+
+    Likewise, unregistering a formula cell that didn't need to be registered
+    (or wasn't registered) is entirely harmless.  Even unregistering a cell
+    that didn't contain a formula cell is harmless, and essentially does
+    nothing.  As such, it's probably a good idea to unregister a cell whenever
+    a new cell value is being placed.
+
+Let's obtain all formula cells in need to re-calculation::
+
+    modified_formula_cells = { A10 };
+    dirty_cells = ixion::query_and_sort_dirty_cells(cxt, ixion::abs_range_set_t(), &modified_formula_cells);
+    cout << "number of dirty cells: " << dirty_cells.size() << endl;
+
+Here, we are only passing one modified formula cell which is A10, and no other
+cells being modified.  Since cell A11 references ``A1:A10`` and A10's value has
+changed, this should also trigger A11 for re-calculation.  Running this code
+should produce the following output:
+
+.. code-block:: text
+
+    number of dirty cells: 2
+
+Let's calculate all affected formula cells and check the results of A10 and A11::
+
+    ixion::calculate_sorted_cells(cxt, dirty_cells, 0);
+    value = cxt.get_numeric_value(A10);
+    cout << "value of A10: " << value << endl;
+    value = cxt.get_numeric_value(A11);
+    cout << "value of A11: " << value << endl;
+
+Running this code should produce the following output:
+
+.. code-block:: text
+
+    value of A10: 75
+    value of A11: 12
+
+The complete source code of this example is avaiable `here <https://gitlab.com/ixion/ixion/-/blob/master/doc_example/model_context_simple.cpp>`_.
+
diff --git a/doc/doxygen.conf b/doc/doxygen.conf
new file mode 100644
index 0000000..ee4cd24
--- /dev/null
+++ b/doc/doxygen.conf
@@ -0,0 +1,2276 @@
+# Doxyfile 1.8.6
+
+# This file describes the settings to be used by the documentation system
+# doxygen (www.doxygen.org) for a project.
+#
+# All text after a double hash (##) is considered a comment and is placed in
+# front of the TAG it is preceding.
+#
+# All text after a single hash (#) is considered a comment and will be ignored.
+# The format is:
+# TAG = value [value, ...]
+# For lists, items can also be appended using:
+# TAG += value [value, ...]
+# Values that contain spaces should be placed between quotes (\" \").
+
+#---------------------------------------------------------------------------
+# Project related configuration options
+#---------------------------------------------------------------------------
+
+# This tag specifies the encoding used for all characters in the config file
+# that follow. The default is UTF-8 which is also the encoding used for all text
+# before the first occurrence of this tag. Doxygen uses libiconv (or the iconv
+# built into libc) for the transcoding. See http://www.gnu.org/software/libiconv
+# for the list of possible encodings.
+# The default value is: UTF-8.
+
+DOXYFILE_ENCODING      = UTF-8
+
+# The PROJECT_NAME tag is a single word (or a sequence of words surrounded by
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+# project for which the documentation is generated. This name is used in the
+# title of most generated pages and in a few other places.
+# The default value is: My Project.
+
+PROJECT_NAME           = "Ixion"
+
+# The PROJECT_NUMBER tag can be used to enter a project or revision number. This
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+
+PROJECT_NUMBER         =
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+PROJECT_BRIEF          =
+
+# With the PROJECT_LOGO tag one can specify an logo or icon that is included in
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+
+PROJECT_LOGO           =
+
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+OUTPUT_DIRECTORY       = _doxygen
+
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+# The default value is: NO.
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+CREATE_SUBDIRS         = NO
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+# If the JAVADOC_AUTOBRIEF tag is set to YES then doxygen will interpret the
+# first line (until the first dot) of a Javadoc-style comment as the brief
+# description. If set to NO, the Javadoc-style will behave just like regular Qt-
+# style comments (thus requiring an explicit @brief command for a brief
+# description.)
+# The default value is: NO.
+
+JAVADOC_AUTOBRIEF      = NO
+
+# If the QT_AUTOBRIEF tag is set to YES then doxygen will interpret the first
+# line (until the first dot) of a Qt-style comment as the brief description. If
+# set to NO, the Qt-style will behave just like regular Qt-style comments (thus
+# requiring an explicit \brief command for a brief description.)
+# The default value is: NO.
+
+QT_AUTOBRIEF           = NO
+
+# The MULTILINE_CPP_IS_BRIEF tag can be set to YES to make doxygen treat a
+# multi-line C++ special comment block (i.e. a block of //! or /// comments) as
+# a brief description. This used to be the default behavior. The new default is
+# to treat a multi-line C++ comment block as a detailed description. Set this
+# tag to YES if you prefer the old behavior instead.
+#
+# Note that setting this tag to YES also means that rational rose comments are
+# not recognized any more.
+# The default value is: NO.
+
+MULTILINE_CPP_IS_BRIEF = NO
+
+# If the INHERIT_DOCS tag is set to YES then an undocumented member inherits the
+# documentation from any documented member that it re-implements.
+# The default value is: YES.
+
+INHERIT_DOCS           = YES
+
+# If the SEPARATE_MEMBER_PAGES tag is set to YES, then doxygen will produce a
+# new page for each member. If set to NO, the documentation of a member will be
+# part of the file/class/namespace that contains it.
+# The default value is: NO.
+
+SEPARATE_MEMBER_PAGES  = NO
+
+# The TAB_SIZE tag can be used to set the number of spaces in a tab. Doxygen
+# uses this value to replace tabs by spaces in code fragments.
+# Minimum value: 1, maximum value: 16, default value: 4.
+
+TAB_SIZE               = 4
+
+# This tag can be used to specify a number of aliases that act as commands in
+# the documentation. An alias has the form:
+# name=value
+# For example adding
+# "sideeffect=@par Side Effects:\n"
+# will allow you to put the command \sideeffect (or @sideeffect) in the
+# documentation, which will result in a user-defined paragraph with heading
+# "Side Effects:". You can put \n's in the value part of an alias to insert
+# newlines.
+
+ALIASES                =
+
+# This tag can be used to specify a number of word-keyword mappings (TCL only).
+# A mapping has the form "name=value". For example adding "class=itcl::class"
+# will allow you to use the command class in the itcl::class meaning.
+
+TCL_SUBST              =
+
+# Set the OPTIMIZE_OUTPUT_FOR_C tag to YES if your project consists of C sources
+# only. Doxygen will then generate output that is more tailored for C. For
+# instance, some of the names that are used will be different. The list of all
+# members will be omitted, etc.
+# The default value is: NO.
+
+OPTIMIZE_OUTPUT_FOR_C  = NO
+
+# Set the OPTIMIZE_OUTPUT_JAVA tag to YES if your project consists of Java or
+# Python sources only. Doxygen will then generate output that is more tailored
+# for that language. For instance, namespaces will be presented as packages,
+# qualified scopes will look different, etc.
+# The default value is: NO.
+
+OPTIMIZE_OUTPUT_JAVA   = NO
+
+# Set the OPTIMIZE_FOR_FORTRAN tag to YES if your project consists of Fortran
+# sources. Doxygen will then generate output that is tailored for Fortran.
+# The default value is: NO.
+
+OPTIMIZE_FOR_FORTRAN   = NO
+
+# Set the OPTIMIZE_OUTPUT_VHDL tag to YES if your project consists of VHDL
+# sources. Doxygen will then generate output that is tailored for VHDL.
+# The default value is: NO.
+
+OPTIMIZE_OUTPUT_VHDL   = NO
+
+# Doxygen selects the parser to use depending on the extension of the files it
+# parses. With this tag you can assign which parser to use for a given
+# extension. Doxygen has a built-in mapping, but you can override or extend it
+# using this tag. The format is ext=language, where ext is a file extension, and
+# language is one of the parsers supported by doxygen: IDL, Java, Javascript,
+# C#, C, C++, D, PHP, Objective-C, Python, Fortran, VHDL. For instance to make
+# doxygen treat .inc files as Fortran files (default is PHP), and .f files as C
+# (default is Fortran), use: inc=Fortran f=C.
+#
+# Note For files without extension you can use no_extension as a placeholder.
+#
+# Note that for custom extensions you also need to set FILE_PATTERNS otherwise
+# the files are not read by doxygen.
+
+EXTENSION_MAPPING      =
+
+# If the MARKDOWN_SUPPORT tag is enabled then doxygen pre-processes all comments
+# according to the Markdown format, which allows for more readable
+# documentation. See http://daringfireball.net/projects/markdown/ for details.
+# The output of markdown processing is further processed by doxygen, so you can
+# mix doxygen, HTML, and XML commands with Markdown formatting. Disable only in
+# case of backward compatibilities issues.
+# The default value is: YES.
+
+MARKDOWN_SUPPORT       = YES
+
+# When enabled doxygen tries to link words that correspond to documented
+# classes, or namespaces to their corresponding documentation. Such a link can
+# be prevented in individual cases by by putting a % sign in front of the word
+# or globally by setting AUTOLINK_SUPPORT to NO.
+# The default value is: YES.
+
+AUTOLINK_SUPPORT       = YES
+
+# If you use STL classes (i.e. std::string, std::vector, etc.) but do not want
+# to include (a tag file for) the STL sources as input, then you should set this
+# tag to YES in order to let doxygen match functions declarations and
+# definitions whose arguments contain STL classes (e.g. func(std::string);
+# versus func(std::string) {}). This also make the inheritance and collaboration
+# diagrams that involve STL classes more complete and accurate.
+# The default value is: NO.
+
+BUILTIN_STL_SUPPORT    = NO
+
+# If you use Microsoft's C++/CLI language, you should set this option to YES to
+# enable parsing support.
+# The default value is: NO.
+
+CPP_CLI_SUPPORT        = NO
+
+# Set the SIP_SUPPORT tag to YES if your project consists of sip (see:
+# http://www.riverbankcomputing.co.uk/software/sip/intro) sources only. Doxygen
+# will parse them like normal C++ but will assume all classes use public instead
+# of private inheritance when no explicit protection keyword is present.
+# The default value is: NO.
+
+SIP_SUPPORT            = NO
+
+# For Microsoft's IDL there are propget and propput attributes to indicate
+# getter and setter methods for a property. Setting this option to YES will make
+# doxygen to replace the get and set methods by a property in the documentation.
+# This will only work if the methods are indeed getting or setting a simple
+# type. If this is not the case, or you want to show the methods anyway, you
+# should set this option to NO.
+# The default value is: YES.
+
+IDL_PROPERTY_SUPPORT   = YES
+
+# If member grouping is used in the documentation and the DISTRIBUTE_GROUP_DOC
+# tag is set to YES, then doxygen will reuse the documentation of the first
+# member in the group (if any) for the other members of the group. By default
+# all members of a group must be documented explicitly.
+# The default value is: NO.
+
+DISTRIBUTE_GROUP_DOC   = NO
+
+# Set the SUBGROUPING tag to YES to allow class member groups of the same type
+# (for instance a group of public functions) to be put as a subgroup of that
+# type (e.g. under the Public Functions section). Set it to NO to prevent
+# subgrouping. Alternatively, this can be done per class using the
+# \nosubgrouping command.
+# The default value is: YES.
+
+SUBGROUPING            = YES
+
+# When the INLINE_GROUPED_CLASSES tag is set to YES, classes, structs and unions
+# are shown inside the group in which they are included (e.g. using \ingroup)
+# instead of on a separate page (for HTML and Man pages) or section (for LaTeX
+# and RTF).
+#
+# Note that this feature does not work in combination with
+# SEPARATE_MEMBER_PAGES.
+# The default value is: NO.
+
+INLINE_GROUPED_CLASSES = NO
+
+# When the INLINE_SIMPLE_STRUCTS tag is set to YES, structs, classes, and unions
+# with only public data fields or simple typedef fields will be shown inline in
+# the documentation of the scope in which they are defined (i.e. file,
+# namespace, or group documentation), provided this scope is documented. If set
+# to NO, structs, classes, and unions are shown on a separate page (for HTML and
+# Man pages) or section (for LaTeX and RTF).
+# The default value is: NO.
+
+INLINE_SIMPLE_STRUCTS  = NO
+
+# When TYPEDEF_HIDES_STRUCT tag is enabled, a typedef of a struct, union, or
+# enum is documented as struct, union, or enum with the name of the typedef. So
+# typedef struct TypeS {} TypeT, will appear in the documentation as a struct
+# with name TypeT. When disabled the typedef will appear as a member of a file,
+# namespace, or class. And the struct will be named TypeS. This can typically be
+# useful for C code in case the coding convention dictates that all compound
+# types are typedef'ed and only the typedef is referenced, never the tag name.
+# The default value is: NO.
+
+TYPEDEF_HIDES_STRUCT   = NO
+
+# The size of the symbol lookup cache can be set using LOOKUP_CACHE_SIZE. This
+# cache is used to resolve symbols given their name and scope. Since this can be
+# an expensive process and often the same symbol appears multiple times in the
+# code, doxygen keeps a cache of pre-resolved symbols. If the cache is too small
+# doxygen will become slower. If the cache is too large, memory is wasted. The
+# cache size is given by this formula: 2^(16+LOOKUP_CACHE_SIZE). The valid range
+# is 0..9, the default is 0, corresponding to a cache size of 2^16=65536
+# symbols. At the end of a run doxygen will report the cache usage and suggest
+# the optimal cache size from a speed point of view.
+# Minimum value: 0, maximum value: 9, default value: 0.
+
+LOOKUP_CACHE_SIZE      = 0
+
+#---------------------------------------------------------------------------
+# Build related configuration options
+#---------------------------------------------------------------------------
+
+# If the EXTRACT_ALL tag is set to YES doxygen will assume all entities in
+# documentation are documented, even if no documentation was available. Private
+# class members and static file members will be hidden unless the
+# EXTRACT_PRIVATE respectively EXTRACT_STATIC tags are set to YES.
+# Note: This will also disable the warnings about undocumented members that are
+# normally produced when WARNINGS is set to YES.
+# The default value is: NO.
+
+EXTRACT_ALL            = NO
+
+# If the EXTRACT_PRIVATE tag is set to YES all private members of a class will
+# be included in the documentation.
+# The default value is: NO.
+
+EXTRACT_PRIVATE        = NO
+
+# If the EXTRACT_PACKAGE tag is set to YES all members with package or internal
+# scope will be included in the documentation.
+# The default value is: NO.
+
+EXTRACT_PACKAGE        = NO
+
+# If the EXTRACT_STATIC tag is set to YES all static members of a file will be
+# included in the documentation.
+# The default value is: NO.
+
+EXTRACT_STATIC         = NO
+
+# If the EXTRACT_LOCAL_CLASSES tag is set to YES classes (and structs) defined
+# locally in source files will be included in the documentation. If set to NO
+# only classes defined in header files are included. Does not have any effect
+# for Java sources.
+# The default value is: YES.
+
+EXTRACT_LOCAL_CLASSES  = YES
+
+# This flag is only useful for Objective-C code. When set to YES local methods,
+# which are defined in the implementation section but not in the interface are
+# included in the documentation. If set to NO only methods in the interface are
+# included.
+# The default value is: NO.
+
+EXTRACT_LOCAL_METHODS  = NO
+
+# If this flag is set to YES, the members of anonymous namespaces will be
+# extracted and appear in the documentation as a namespace called
+# 'anonymous_namespace{file}', where file will be replaced with the base name of
+# the file that contains the anonymous namespace. By default anonymous namespace
+# are hidden.
+# The default value is: NO.
+
+EXTRACT_ANON_NSPACES   = NO
+
+# If the HIDE_UNDOC_MEMBERS tag is set to YES, doxygen will hide all
+# undocumented members inside documented classes or files. If set to NO these
+# members will be included in the various overviews, but no documentation
+# section is generated. This option has no effect if EXTRACT_ALL is enabled.
+# The default value is: NO.
+
+HIDE_UNDOC_MEMBERS     = NO
+
+# If the HIDE_UNDOC_CLASSES tag is set to YES, doxygen will hide all
+# undocumented classes that are normally visible in the class hierarchy. If set
+# to NO these classes will be included in the various overviews. This option has
+# no effect if EXTRACT_ALL is enabled.
+# The default value is: NO.
+
+HIDE_UNDOC_CLASSES     = NO
+
+# If the HIDE_FRIEND_COMPOUNDS tag is set to YES, doxygen will hide all friend
+# (class|struct|union) declarations. If set to NO these declarations will be
+# included in the documentation.
+# The default value is: NO.
+
+HIDE_FRIEND_COMPOUNDS  = NO
+
+# If the HIDE_IN_BODY_DOCS tag is set to YES, doxygen will hide any
+# documentation blocks found inside the body of a function. If set to NO these
+# blocks will be appended to the function's detailed documentation block.
+# The default value is: NO.
+
+HIDE_IN_BODY_DOCS      = NO
+
+# The INTERNAL_DOCS tag determines if documentation that is typed after a
+# \internal command is included. If the tag is set to NO then the documentation
+# will be excluded. Set it to YES to include the internal documentation.
+# The default value is: NO.
+
+INTERNAL_DOCS          = NO
+
+# If the CASE_SENSE_NAMES tag is set to NO then doxygen will only generate file
+# names in lower-case letters. If set to YES upper-case letters are also
+# allowed. This is useful if you have classes or files whose names only differ
+# in case and if your file system supports case sensitive file names. Windows
+# and Mac users are advised to set this option to NO.
+# The default value is: system dependent.
+
+CASE_SENSE_NAMES       = YES
+
+# If the HIDE_SCOPE_NAMES tag is set to NO then doxygen will show members with
+# their full class and namespace scopes in the documentation. If set to YES the
+# scope will be hidden.
+# The default value is: NO.
+
+HIDE_SCOPE_NAMES       = NO
+
+# If the SHOW_INCLUDE_FILES tag is set to YES then doxygen will put a list of
+# the files that are included by a file in the documentation of that file.
+# The default value is: YES.
+
+SHOW_INCLUDE_FILES     = YES
+
+# If the SHOW_GROUPED_MEMB_INC tag is set to YES then Doxygen will add for each
+# grouped member an include statement to the documentation, telling the reader
+# which file to include in order to use the member.
+# The default value is: NO.
+
+SHOW_GROUPED_MEMB_INC  = NO
+
+# If the FORCE_LOCAL_INCLUDES tag is set to YES then doxygen will list include
+# files with double quotes in the documentation rather than with sharp brackets.
+# The default value is: NO.
+
+FORCE_LOCAL_INCLUDES   = NO
+
+# If the INLINE_INFO tag is set to YES then a tag [inline] is inserted in the
+# documentation for inline members.
+# The default value is: YES.
+
+INLINE_INFO            = YES
+
+# If the SORT_MEMBER_DOCS tag is set to YES then doxygen will sort the
+# (detailed) documentation of file and class members alphabetically by member
+# name. If set to NO the members will appear in declaration order.
+# The default value is: YES.
+
+SORT_MEMBER_DOCS       = YES
+
+# If the SORT_BRIEF_DOCS tag is set to YES then doxygen will sort the brief
+# descriptions of file, namespace and class members alphabetically by member
+# name. If set to NO the members will appear in declaration order. Note that
+# this will also influence the order of the classes in the class list.
+# The default value is: NO.
+
+SORT_BRIEF_DOCS        = NO
+
+# If the SORT_MEMBERS_CTORS_1ST tag is set to YES then doxygen will sort the
+# (brief and detailed) documentation of class members so that constructors and
+# destructors are listed first. If set to NO the constructors will appear in the
+# respective orders defined by SORT_BRIEF_DOCS and SORT_MEMBER_DOCS.
+# Note: If SORT_BRIEF_DOCS is set to NO this option is ignored for sorting brief
+# member documentation.
+# Note: If SORT_MEMBER_DOCS is set to NO this option is ignored for sorting
+# detailed member documentation.
+# The default value is: NO.
+
+SORT_MEMBERS_CTORS_1ST = NO
+
+# If the SORT_GROUP_NAMES tag is set to YES then doxygen will sort the hierarchy
+# of group names into alphabetical order. If set to NO the group names will
+# appear in their defined order.
+# The default value is: NO.
+
+SORT_GROUP_NAMES       = NO
+
+# If the SORT_BY_SCOPE_NAME tag is set to YES, the class list will be sorted by
+# fully-qualified names, including namespaces. If set to NO, the class list will
+# be sorted only by class name, not including the namespace part.
+# Note: This option is not very useful if HIDE_SCOPE_NAMES is set to YES.
+# Note: This option applies only to the class list, not to the alphabetical
+# list.
+# The default value is: NO.
+
+SORT_BY_SCOPE_NAME     = NO
+
+# If the STRICT_PROTO_MATCHING option is enabled and doxygen fails to do proper
+# type resolution of all parameters of a function it will reject a match between
+# the prototype and the implementation of a member function even if there is
+# only one candidate or it is obvious which candidate to choose by doing a
+# simple string match. By disabling STRICT_PROTO_MATCHING doxygen will still
+# accept a match between prototype and implementation in such cases.
+# The default value is: NO.
+
+STRICT_PROTO_MATCHING  = NO
+
+# The GENERATE_TODOLIST tag can be used to enable ( YES) or disable ( NO) the
+# todo list. This list is created by putting \todo commands in the
+# documentation.
+# The default value is: YES.
+
+GENERATE_TODOLIST      = YES
+
+# The GENERATE_TESTLIST tag can be used to enable ( YES) or disable ( NO) the
+# test list. This list is created by putting \test commands in the
+# documentation.
+# The default value is: YES.
+
+GENERATE_TESTLIST      = YES
+
+# The GENERATE_BUGLIST tag can be used to enable ( YES) or disable ( NO) the bug
+# list. This list is created by putting \bug commands in the documentation.
+# The default value is: YES.
+
+GENERATE_BUGLIST       = YES
+
+# The GENERATE_DEPRECATEDLIST tag can be used to enable ( YES) or disable ( NO)
+# the deprecated list. This list is created by putting \deprecated commands in
+# the documentation.
+# The default value is: YES.
+
+GENERATE_DEPRECATEDLIST= YES
+
+# The ENABLED_SECTIONS tag can be used to enable conditional documentation
+# sections, marked by \if <section_label> ... \endif and \cond <section_label>
+# ... \endcond blocks.
+
+ENABLED_SECTIONS       =
+
+# The MAX_INITIALIZER_LINES tag determines the maximum number of lines that the
+# initial value of a variable or macro / define can have for it to appear in the
+# documentation. If the initializer consists of more lines than specified here
+# it will be hidden. Use a value of 0 to hide initializers completely. The
+# appearance of the value of individual variables and macros / defines can be
+# controlled using \showinitializer or \hideinitializer command in the
+# documentation regardless of this setting.
+# Minimum value: 0, maximum value: 10000, default value: 30.
+
+MAX_INITIALIZER_LINES  = 30
+
+# Set the SHOW_USED_FILES tag to NO to disable the list of files generated at
+# the bottom of the documentation of classes and structs. If set to YES the list
+# will mention the files that were used to generate the documentation.
+# The default value is: YES.
+
+SHOW_USED_FILES        = NO
+
+# Set the SHOW_FILES tag to NO to disable the generation of the Files page. This
+# will remove the Files entry from the Quick Index and from the Folder Tree View
+# (if specified).
+# The default value is: YES.
+
+SHOW_FILES             = YES
+
+# Set the SHOW_NAMESPACES tag to NO to disable the generation of the Namespaces
+# page. This will remove the Namespaces entry from the Quick Index and from the
+# Folder Tree View (if specified).
+# The default value is: YES.
+
+SHOW_NAMESPACES        = YES
+
+# The FILE_VERSION_FILTER tag can be used to specify a program or script that
+# doxygen should invoke to get the current version for each file (typically from
+# the version control system). Doxygen will invoke the program by executing (via
+# popen()) the command command input-file, where command is the value of the
+# FILE_VERSION_FILTER tag, and input-file is the name of an input file provided
+# by doxygen. Whatever the program writes to standard output is used as the file
+# version. For an example see the documentation.
+
+FILE_VERSION_FILTER    =
+
+# The LAYOUT_FILE tag can be used to specify a layout file which will be parsed
+# by doxygen. The layout file controls the global structure of the generated
+# output files in an output format independent way. To create the layout file
+# that represents doxygen's defaults, run doxygen with the -l option. You can
+# optionally specify a file name after the option, if omitted DoxygenLayout.xml
+# will be used as the name of the layout file.
+#
+# Note that if you run doxygen from a directory containing a file called
+# DoxygenLayout.xml, doxygen will parse it automatically even if the LAYOUT_FILE
+# tag is left empty.
+
+LAYOUT_FILE            =
+
+# The CITE_BIB_FILES tag can be used to specify one or more bib files containing
+# the reference definitions. This must be a list of .bib files. The .bib
+# extension is automatically appended if omitted. This requires the bibtex tool
+# to be installed. See also http://en.wikipedia.org/wiki/BibTeX for more info.
+# For LaTeX the style of the bibliography can be controlled using
+# LATEX_BIB_STYLE. To use this feature you need bibtex and perl available in the
+# search path. Do not use file names with spaces, bibtex cannot handle them. See
+# also \cite for info how to create references.
+
+CITE_BIB_FILES         =
+
+#---------------------------------------------------------------------------
+# Configuration options related to warning and progress messages
+#---------------------------------------------------------------------------
+
+# The QUIET tag can be used to turn on/off the messages that are generated to
+# standard output by doxygen. If QUIET is set to YES this implies that the
+# messages are off.
+# The default value is: NO.
+
+QUIET                  = NO
+
+# The WARNINGS tag can be used to turn on/off the warning messages that are
+# generated to standard error ( stderr) by doxygen. If WARNINGS is set to YES
+# this implies that the warnings are on.
+#
+# Tip: Turn warnings on while writing the documentation.
+# The default value is: YES.
+
+WARNINGS               = YES
+
+# If the WARN_IF_UNDOCUMENTED tag is set to YES, then doxygen will generate
+# warnings for undocumented members. If EXTRACT_ALL is set to YES then this flag
+# will automatically be disabled.
+# The default value is: YES.
+
+WARN_IF_UNDOCUMENTED   = NO
+
+# If the WARN_IF_DOC_ERROR tag is set to YES, doxygen will generate warnings for
+# potential errors in the documentation, such as not documenting some parameters
+# in a documented function, or documenting parameters that don't exist or using
+# markup commands wrongly.
+# The default value is: YES.
+
+WARN_IF_DOC_ERROR      = YES
+
+# This WARN_NO_PARAMDOC option can be enabled to get warnings for functions that
+# are documented, but have no documentation for their parameters or return
+# value. If set to NO doxygen will only warn about wrong or incomplete parameter
+# documentation, but not about the absence of documentation.
+# The default value is: NO.
+
+WARN_NO_PARAMDOC       = NO
+
+# The WARN_FORMAT tag determines the format of the warning messages that doxygen
+# can produce. The string should contain the $file, $line, and $text tags, which
+# will be replaced by the file and line number from which the warning originated
+# and the warning text. Optionally the format may contain $version, which will
+# be replaced by the version of the file (if it could be obtained via
+# FILE_VERSION_FILTER)
+# The default value is: $file:$line: $text.
+
+WARN_FORMAT            = "$file:$line: $text"
+
+# The WARN_LOGFILE tag can be used to specify a file to which warning and error
+# messages should be written. If left blank the output is written to standard
+# error (stderr).
+
+WARN_LOGFILE           =
+
+#---------------------------------------------------------------------------
+# Configuration options related to the input files
+#---------------------------------------------------------------------------
+
+# The INPUT tag is used to specify the files and/or directories that contain
+# documented source files. You may enter file names like myfile.cpp or
+# directories like /usr/src/myproject. Separate the files or directories with
+# spaces.
+# Note: If this tag is empty the current directory is searched.
+
+INPUT = ../include
+
+# This tag can be used to specify the character encoding of the source files
+# that doxygen parses. Internally doxygen uses the UTF-8 encoding. Doxygen uses
+# libiconv (or the iconv built into libc) for the transcoding. See the libiconv
+# documentation (see: http://www.gnu.org/software/libiconv) for the list of
+# possible encodings.
+# The default value is: UTF-8.
+
+INPUT_ENCODING         = UTF-8
+
+# If the value of the INPUT tag contains directories, you can use the
+# FILE_PATTERNS tag to specify one or more wildcard patterns (like *.cpp and
+# *.h) to filter out the source-files in the directories. If left blank the
+# following patterns are tested:*.c, *.cc, *.cxx, *.cpp, *.c++, *.java, *.ii,
+# *.ixx, *.ipp, *.i++, *.inl, *.idl, *.ddl, *.odl, *.h, *.hh, *.hxx, *.hpp,
+# *.h++, *.cs, *.d, *.php, *.php4, *.php5, *.phtml, *.inc, *.m, *.markdown,
+# *.md, *.mm, *.dox, *.py, *.f90, *.f, *.for, *.tcl, *.vhd, *.vhdl, *.ucf,
+# *.qsf, *.as and *.js.
+
+FILE_PATTERNS          = *.hpp
+
+# The RECURSIVE tag can be used to specify whether or not subdirectories should
+# be searched for input files as well.
+# The default value is: NO.
+
+RECURSIVE              = YES
+
+# The EXCLUDE tag can be used to specify files and/or directories that should be
+# excluded from the INPUT source files. This way you can easily exclude a
+# subdirectory from a directory tree whose root is specified with the INPUT tag.
+#
+# Note that relative paths are relative to the directory from which doxygen is
+# run.
+
+EXCLUDE                =
+
+# The EXCLUDE_SYMLINKS tag can be used to select whether or not files or
+# directories that are symbolic links (a Unix file system feature) are excluded
+# from the input.
+# The default value is: NO.
+
+EXCLUDE_SYMLINKS       = NO
+
+# If the value of the INPUT tag contains directories, you can use the
+# EXCLUDE_PATTERNS tag to specify one or more wildcard patterns to exclude
+# certain files from those directories.
+#
+# Note that the wildcards are matched against the file with absolute path, so to
+# exclude all test directories for example use the pattern */test/*
+
+EXCLUDE_PATTERNS       =
+
+# The EXCLUDE_SYMBOLS tag can be used to specify one or more symbol names
+# (namespaces, classes, functions, etc.) that should be excluded from the
+# output. The symbol name can be a fully qualified name, a word, or if the
+# wildcard * is used, a substring. Examples: ANamespace, AClass,
+# AClass::ANamespace, ANamespace::*Test
+#
+# Note that the wildcards are matched against the file with absolute path, so to
+# exclude all test directories use the pattern */test/*
+
+EXCLUDE_SYMBOLS        =
+
+# The EXAMPLE_PATH tag can be used to specify one or more files or directories
+# that contain example code fragments that are included (see the \include
+# command).
+
+EXAMPLE_PATH           =
+
+# If the value of the EXAMPLE_PATH tag contains directories, you can use the
+# EXAMPLE_PATTERNS tag to specify one or more wildcard pattern (like *.cpp and
+# *.h) to filter out the source-files in the directories. If left blank all
+# files are included.
+
+EXAMPLE_PATTERNS       =
+
+# If the EXAMPLE_RECURSIVE tag is set to YES then subdirectories will be
+# searched for input files to be used with the \include or \dontinclude commands
+# irrespective of the value of the RECURSIVE tag.
+# The default value is: NO.
+
+EXAMPLE_RECURSIVE      = NO
+
+# The IMAGE_PATH tag can be used to specify one or more files or directories
+# that contain images that are to be included in the documentation (see the
+# \image command).
+
+IMAGE_PATH             =
+
+# The INPUT_FILTER tag can be used to specify a program that doxygen should
+# invoke to filter for each input file. Doxygen will invoke the filter program
+# by executing (via popen()) the command:
+#
+# <filter> <input-file>
+#
+# where <filter> is the value of the INPUT_FILTER tag, and <input-file> is the
+# name of an input file. Doxygen will then use the output that the filter
+# program writes to standard output. If FILTER_PATTERNS is specified, this tag
+# will be ignored.
+#
+# Note that the filter must not add or remove lines; it is applied before the
+# code is scanned, but not when the output code is generated. If lines are added
+# or removed, the anchors will not be placed correctly.
+
+INPUT_FILTER           =
+
+# The FILTER_PATTERNS tag can be used to specify filters on a per file pattern
+# basis. Doxygen will compare the file name with each pattern and apply the
+# filter if there is a match. The filters are a list of the form: pattern=filter
+# (like *.cpp=my_cpp_filter). See INPUT_FILTER for further information on how
+# filters are used. If the FILTER_PATTERNS tag is empty or if none of the
+# patterns match the file name, INPUT_FILTER is applied.
+
+FILTER_PATTERNS        =
+
+# If the FILTER_SOURCE_FILES tag is set to YES, the input filter (if set using
+# INPUT_FILTER ) will also be used to filter the input files that are used for
+# producing the source files to browse (i.e. when SOURCE_BROWSER is set to YES).
+# The default value is: NO.
+
+FILTER_SOURCE_FILES    = NO
+
+# The FILTER_SOURCE_PATTERNS tag can be used to specify source filters per file
+# pattern. A pattern will override the setting for FILTER_PATTERN (if any) and
+# it is also possible to disable source filtering for a specific pattern using
+# *.ext= (so without naming a filter).
+# This tag requires that the tag FILTER_SOURCE_FILES is set to YES.
+
+FILTER_SOURCE_PATTERNS =
+
+# If the USE_MDFILE_AS_MAINPAGE tag refers to the name of a markdown file that
+# is part of the input, its contents will be placed on the main page
+# (index.html). This can be useful if you have a project on for instance GitHub
+# and want to reuse the introduction page also for the doxygen output.
+
+USE_MDFILE_AS_MAINPAGE =
+
+#---------------------------------------------------------------------------
+# Configuration options related to source browsing
+#---------------------------------------------------------------------------
+
+# If the SOURCE_BROWSER tag is set to YES then a list of source files will be
+# generated. Documented entities will be cross-referenced with these sources.
+#
+# Note: To get rid of all source code in the generated output, make sure that
+# also VERBATIM_HEADERS is set to NO.
+# The default value is: NO.
+
+SOURCE_BROWSER         = NO
+
+# Setting the INLINE_SOURCES tag to YES will include the body of functions,
+# classes and enums directly into the documentation.
+# The default value is: NO.
+
+INLINE_SOURCES         = NO
+
+# Setting the STRIP_CODE_COMMENTS tag to YES will instruct doxygen to hide any
+# special comment blocks from generated source code fragments. Normal C, C++ and
+# Fortran comments will always remain visible.
+# The default value is: YES.
+
+STRIP_CODE_COMMENTS    = YES
+
+# If the REFERENCED_BY_RELATION tag is set to YES then for each documented
+# function all documented functions referencing it will be listed.
+# The default value is: NO.
+
+REFERENCED_BY_RELATION = NO
+
+# If the REFERENCES_RELATION tag is set to YES then for each documented function
+# all documented entities called/used by that function will be listed.
+# The default value is: NO.
+
+REFERENCES_RELATION    = NO
+
+# If the REFERENCES_LINK_SOURCE tag is set to YES and SOURCE_BROWSER tag is set
+# to YES, then the hyperlinks from functions in REFERENCES_RELATION and
+# REFERENCED_BY_RELATION lists will link to the source code. Otherwise they will
+# link to the documentation.
+# The default value is: YES.
+
+REFERENCES_LINK_SOURCE = YES
+
+# If SOURCE_TOOLTIPS is enabled (the default) then hovering a hyperlink in the
+# source code will show a tooltip with additional information such as prototype,
+# brief description and links to the definition and documentation. Since this
+# will make the HTML file larger and loading of large files a bit slower, you
+# can opt to disable this feature.
+# The default value is: YES.
+# This tag requires that the tag SOURCE_BROWSER is set to YES.
+
+SOURCE_TOOLTIPS        = YES
+
+# If the USE_HTAGS tag is set to YES then the references to source code will
+# point to the HTML generated by the htags(1) tool instead of doxygen built-in
+# source browser. The htags tool is part of GNU's global source tagging system
+# (see http://www.gnu.org/software/global/global.html). You will need version
+# 4.8.6 or higher.
+#
+# To use it do the following:
+# - Install the latest version of global
+# - Enable SOURCE_BROWSER and USE_HTAGS in the config file
+# - Make sure the INPUT points to the root of the source tree
+# - Run doxygen as normal
+#
+# Doxygen will invoke htags (and that will in turn invoke gtags), so these
+# tools must be available from the command line (i.e. in the search path).
+#
+# The result: instead of the source browser generated by doxygen, the links to
+# source code will now point to the output of htags.
+# The default value is: NO.
+# This tag requires that the tag SOURCE_BROWSER is set to YES.
+
+USE_HTAGS              = NO
+
+# If the VERBATIM_HEADERS tag is set the YES then doxygen will generate a
+# verbatim copy of the header file for each class for which an include is
+# specified. Set to NO to disable this.
+# See also: Section \class.
+# The default value is: YES.
+
+VERBATIM_HEADERS       = YES
+
+#---------------------------------------------------------------------------
+# Configuration options related to the alphabetical class index
+#---------------------------------------------------------------------------
+
+# If the ALPHABETICAL_INDEX tag is set to YES, an alphabetical index of all
+# compounds will be generated. Enable this if the project contains a lot of
+# classes, structs, unions or interfaces.
+# The default value is: YES.
+
+ALPHABETICAL_INDEX     = YES
+
+# The COLS_IN_ALPHA_INDEX tag can be used to specify the number of columns in
+# which the alphabetical index list will be split.
+# Minimum value: 1, maximum value: 20, default value: 5.
+# This tag requires that the tag ALPHABETICAL_INDEX is set to YES.
+
+COLS_IN_ALPHA_INDEX    = 5
+
+# In case all classes in a project start with a common prefix, all classes will
+# be put under the same header in the alphabetical index. The IGNORE_PREFIX tag
+# can be used to specify a prefix (or a list of prefixes) that should be ignored
+# while generating the index headers.
+# This tag requires that the tag ALPHABETICAL_INDEX is set to YES.
+
+IGNORE_PREFIX          =
+
+#---------------------------------------------------------------------------
+# Configuration options related to the HTML output
+#---------------------------------------------------------------------------
+
+# If the GENERATE_HTML tag is set to YES doxygen will generate HTML output
+# The default value is: YES.
+
+GENERATE_HTML          = YES
+
+# The HTML_OUTPUT tag is used to specify where the HTML docs will be put. If a
+# relative path is entered the value of OUTPUT_DIRECTORY will be put in front of
+# it.
+# The default directory is: html.
+# This tag requires that the tag GENERATE_HTML is set to YES.
+
+HTML_OUTPUT            = html
+
+# The HTML_FILE_EXTENSION tag can be used to specify the file extension for each
+# generated HTML page (for example: .htm, .php, .asp).
+# The default value is: .html.
+# This tag requires that the tag GENERATE_HTML is set to YES.
+
+HTML_FILE_EXTENSION    = .html
+
+# The HTML_HEADER tag can be used to specify a user-defined HTML header file for
+# each generated HTML page. If the tag is left blank doxygen will generate a
+# standard header.
+#
+# To get valid HTML the header file that includes any scripts and style sheets
+# that doxygen needs, which is dependent on the configuration options used (e.g.
+# the setting GENERATE_TREEVIEW). It is highly recommended to start with a
+# default header using
+# doxygen -w html new_header.html new_footer.html new_stylesheet.css
+# YourConfigFile
+# and then modify the file new_header.html. See also section "Doxygen usage"
+# for information on how to generate the default header that doxygen normally
+# uses.
+# Note: The header is subject to change so you typically have to regenerate the
+# default header when upgrading to a newer version of doxygen. For a description
+# of the possible markers and block names see the documentation.
+# This tag requires that the tag GENERATE_HTML is set to YES.
+
+HTML_HEADER            =
+
+# The HTML_FOOTER tag can be used to specify a user-defined HTML footer for each
+# generated HTML page. If the tag is left blank doxygen will generate a standard
+# footer. See HTML_HEADER for more information on how to generate a default
+# footer and what special commands can be used inside the footer. See also
+# section "Doxygen usage" for information on how to generate the default footer
+# that doxygen normally uses.
+# This tag requires that the tag GENERATE_HTML is set to YES.
+
+HTML_FOOTER            =
+
+# The HTML_STYLESHEET tag can be used to specify a user-defined cascading style
+# sheet that is used by each HTML page. It can be used to fine-tune the look of
+# the HTML output. If left blank doxygen will generate a default style sheet.
+# See also section "Doxygen usage" for information on how to generate the style
+# sheet that doxygen normally uses.
+# Note: It is recommended to use HTML_EXTRA_STYLESHEET instead of this tag, as
+# it is more robust and this tag (HTML_STYLESHEET) will in the future become
+# obsolete.
+# This tag requires that the tag GENERATE_HTML is set to YES.
+
+HTML_STYLESHEET        =
+
+# The HTML_EXTRA_STYLESHEET tag can be used to specify an additional user-
+# defined cascading style sheet that is included after the standard style sheets
+# created by doxygen. Using this option one can overrule certain style aspects.
+# This is preferred over using HTML_STYLESHEET since it does not replace the
+# standard style sheet and is therefor more robust against future updates.
+# Doxygen will copy the style sheet file to the output directory. For an example
+# see the documentation.
+# This tag requires that the tag GENERATE_HTML is set to YES.
+
+HTML_EXTRA_STYLESHEET  =
+
+# The HTML_EXTRA_FILES tag can be used to specify one or more extra images or
+# other source files which should be copied to the HTML output directory. Note
+# that these files will be copied to the base HTML output directory. Use the
+# $relpath^ marker in the HTML_HEADER and/or HTML_FOOTER files to load these
+# files. In the HTML_STYLESHEET file, use the file name only. Also note that the
+# files will be copied as-is; there are no commands or markers available.
+# This tag requires that the tag GENERATE_HTML is set to YES.
+
+HTML_EXTRA_FILES       =
+
+# The HTML_COLORSTYLE_HUE tag controls the color of the HTML output. Doxygen
+# will adjust the colors in the stylesheet and background images according to
+# this color. Hue is specified as an angle on a colorwheel, see
+# http://en.wikipedia.org/wiki/Hue for more information. For instance the value
+# 0 represents red, 60 is yellow, 120 is green, 180 is cyan, 240 is blue, 300
+# purple, and 360 is red again.
+# Minimum value: 0, maximum value: 359, default value: 220.
+# This tag requires that the tag GENERATE_HTML is set to YES.
+
+HTML_COLORSTYLE_HUE    = 220
+
+# The HTML_COLORSTYLE_SAT tag controls the purity (or saturation) of the colors
+# in the HTML output. For a value of 0 the output will use grayscales only. A
+# value of 255 will produce the most vivid colors.
+# Minimum value: 0, maximum value: 255, default value: 100.
+# This tag requires that the tag GENERATE_HTML is set to YES.
+
+HTML_COLORSTYLE_SAT    = 100
+
+# The HTML_COLORSTYLE_GAMMA tag controls the gamma correction applied to the
+# luminance component of the colors in the HTML output. Values below 100
+# gradually make the output lighter, whereas values above 100 make the output
+# darker. The value divided by 100 is the actual gamma applied, so 80 represents
+# a gamma of 0.8, The value 220 represents a gamma of 2.2, and 100 does not
+# change the gamma.
+# Minimum value: 40, maximum value: 240, default value: 80.
+# This tag requires that the tag GENERATE_HTML is set to YES.
+
+HTML_COLORSTYLE_GAMMA  = 80
+
+# If the HTML_TIMESTAMP tag is set to YES then the footer of each generated HTML
+# page will contain the date and time when the page was generated. Setting this
+# to NO can help when comparing the output of multiple runs.
+# The default value is: YES.
+# This tag requires that the tag GENERATE_HTML is set to YES.
+
+HTML_TIMESTAMP         = YES
+
+# If the HTML_DYNAMIC_SECTIONS tag is set to YES then the generated HTML
+# documentation will contain sections that can be hidden and shown after the
+# page has loaded.
+# The default value is: NO.
+# This tag requires that the tag GENERATE_HTML is set to YES.
+
+HTML_DYNAMIC_SECTIONS  = NO
+
+# With HTML_INDEX_NUM_ENTRIES one can control the preferred number of entries
+# shown in the various tree structured indices initially; the user can expand
+# and collapse entries dynamically later on. Doxygen will expand the tree to
+# such a level that at most the specified number of entries are visible (unless
+# a fully collapsed tree already exceeds this amount). So setting the number of
+# entries 1 will produce a full collapsed tree by default. 0 is a special value
+# representing an infinite number of entries and will result in a full expanded
+# tree by default.
+# Minimum value: 0, maximum value: 9999, default value: 100.
+# This tag requires that the tag GENERATE_HTML is set to YES.
+
+HTML_INDEX_NUM_ENTRIES = 100
+
+# If the GENERATE_DOCSET tag is set to YES, additional index files will be
+# generated that can be used as input for Apple's Xcode 3 integrated development
+# environment (see: http://developer.apple.com/tools/xcode/), introduced with
+# OSX 10.5 (Leopard). To create a documentation set, doxygen will generate a
+# Makefile in the HTML output directory. Running make will produce the docset in
+# that directory and running make install will install the docset in
+# ~/Library/Developer/Shared/Documentation/DocSets so that Xcode will find it at
+# startup. See http://developer.apple.com/tools/creatingdocsetswithdoxygen.html
+# for more information.
+# The default value is: NO.
+# This tag requires that the tag GENERATE_HTML is set to YES.
+
+GENERATE_DOCSET        = NO
+
+# This tag determines the name of the docset feed. A documentation feed provides
+# an umbrella under which multiple documentation sets from a single provider
+# (such as a company or product suite) can be grouped.
+# The default value is: Doxygen generated docs.
+# This tag requires that the tag GENERATE_DOCSET is set to YES.
+
+DOCSET_FEEDNAME        = "Doxygen generated docs"
+
+# This tag specifies a string that should uniquely identify the documentation
+# set bundle. This should be a reverse domain-name style string, e.g.
+# com.mycompany.MyDocSet. Doxygen will append .docset to the name.
+# The default value is: org.doxygen.Project.
+# This tag requires that the tag GENERATE_DOCSET is set to YES.
+
+DOCSET_BUNDLE_ID       = org.doxygen.Project
+
+# The DOCSET_PUBLISHER_ID tag specifies a string that should uniquely identify
+# the documentation publisher. This should be a reverse domain-name style
+# string, e.g. com.mycompany.MyDocSet.documentation.
+# The default value is: org.doxygen.Publisher.
+# This tag requires that the tag GENERATE_DOCSET is set to YES.
+
+DOCSET_PUBLISHER_ID    = org.doxygen.Publisher
+
+# The DOCSET_PUBLISHER_NAME tag identifies the documentation publisher.
+# The default value is: Publisher.
+# This tag requires that the tag GENERATE_DOCSET is set to YES.
+
+DOCSET_PUBLISHER_NAME  = Publisher
+
+# If the GENERATE_HTMLHELP tag is set to YES then doxygen generates three
+# additional HTML index files: index.hhp, index.hhc, and index.hhk. The
+# index.hhp is a project file that can be read by Microsoft's HTML Help Workshop
+# (see: http://www.microsoft.com/en-us/download/details.aspx?id=21138) on
+# Windows.
+#
+# The HTML Help Workshop contains a compiler that can convert all HTML output
+# generated by doxygen into a single compiled HTML file (.chm). Compiled HTML
+# files are now used as the Windows 98 help format, and will replace the old
+# Windows help format (.hlp) on all Windows platforms in the future. Compressed
+# HTML files also contain an index, a table of contents, and you can search for
+# words in the documentation. The HTML workshop also contains a viewer for
+# compressed HTML files.
+# The default value is: NO.
+# This tag requires that the tag GENERATE_HTML is set to YES.
+
+GENERATE_HTMLHELP      = NO
+
+# The CHM_FILE tag can be used to specify the file name of the resulting .chm
+# file. You can add a path in front of the file if the result should not be
+# written to the html output directory.
+# This tag requires that the tag GENERATE_HTMLHELP is set to YES.
+
+CHM_FILE               =
+
+# The HHC_LOCATION tag can be used to specify the location (absolute path
+# including file name) of the HTML help compiler ( hhc.exe). If non-empty
+# doxygen will try to run the HTML help compiler on the generated index.hhp.
+# The file has to be specified with full path.
+# This tag requires that the tag GENERATE_HTMLHELP is set to YES.
+
+HHC_LOCATION           =
+
+# The GENERATE_CHI flag controls if a separate .chi index file is generated (
+# YES) or that it should be included in the master .chm file ( NO).
+# The default value is: NO.
+# This tag requires that the tag GENERATE_HTMLHELP is set to YES.
+
+GENERATE_CHI           = NO
+
+# The CHM_INDEX_ENCODING is used to encode HtmlHelp index ( hhk), content ( hhc)
+# and project file content.
+# This tag requires that the tag GENERATE_HTMLHELP is set to YES.
+
+CHM_INDEX_ENCODING     =
+
+# The BINARY_TOC flag controls whether a binary table of contents is generated (
+# YES) or a normal table of contents ( NO) in the .chm file.
+# The default value is: NO.
+# This tag requires that the tag GENERATE_HTMLHELP is set to YES.
+
+BINARY_TOC             = NO
+
+# The TOC_EXPAND flag can be set to YES to add extra items for group members to
+# the table of contents of the HTML help documentation and to the tree view.
+# The default value is: NO.
+# This tag requires that the tag GENERATE_HTMLHELP is set to YES.
+
+TOC_EXPAND             = NO
+
+# If the GENERATE_QHP tag is set to YES and both QHP_NAMESPACE and
+# QHP_VIRTUAL_FOLDER are set, an additional index file will be generated that
+# can be used as input for Qt's qhelpgenerator to generate a Qt Compressed Help
+# (.qch) of the generated HTML documentation.
+# The default value is: NO.
+# This tag requires that the tag GENERATE_HTML is set to YES.
+
+GENERATE_QHP           = NO
+
+# If the QHG_LOCATION tag is specified, the QCH_FILE tag can be used to specify
+# the file name of the resulting .qch file. The path specified is relative to
+# the HTML output folder.
+# This tag requires that the tag GENERATE_QHP is set to YES.
+
+QCH_FILE               =
+
+# The QHP_NAMESPACE tag specifies the namespace to use when generating Qt Help
+# Project output. For more information please see Qt Help Project / Namespace
+# (see: http://qt-project.org/doc/qt-4.8/qthelpproject.html#namespace).
+# The default value is: org.doxygen.Project.
+# This tag requires that the tag GENERATE_QHP is set to YES.
+
+QHP_NAMESPACE          = org.doxygen.Project
+
+# The QHP_VIRTUAL_FOLDER tag specifies the namespace to use when generating Qt
+# Help Project output. For more information please see Qt Help Project / Virtual
+# Folders (see: http://qt-project.org/doc/qt-4.8/qthelpproject.html#virtual-
+# folders).
+# The default value is: doc.
+# This tag requires that the tag GENERATE_QHP is set to YES.
+
+QHP_VIRTUAL_FOLDER     = doc
+
+# If the QHP_CUST_FILTER_NAME tag is set, it specifies the name of a custom
+# filter to add. For more information please see Qt Help Project / Custom
+# Filters (see: http://qt-project.org/doc/qt-4.8/qthelpproject.html#custom-
+# filters).
+# This tag requires that the tag GENERATE_QHP is set to YES.
+
+QHP_CUST_FILTER_NAME   =
+
+# The QHP_CUST_FILTER_ATTRS tag specifies the list of the attributes of the
+# custom filter to add. For more information please see Qt Help Project / Custom
+# Filters (see: http://qt-project.org/doc/qt-4.8/qthelpproject.html#custom-
+# filters).
+# This tag requires that the tag GENERATE_QHP is set to YES.
+
+QHP_CUST_FILTER_ATTRS  =
+
+# The QHP_SECT_FILTER_ATTRS tag specifies the list of the attributes this
+# project's filter section matches. Qt Help Project / Filter Attributes (see:
+# http://qt-project.org/doc/qt-4.8/qthelpproject.html#filter-attributes).
+# This tag requires that the tag GENERATE_QHP is set to YES.
+
+QHP_SECT_FILTER_ATTRS  =
+
+# The QHG_LOCATION tag can be used to specify the location of Qt's
+# qhelpgenerator. If non-empty doxygen will try to run qhelpgenerator on the
+# generated .qhp file.
+# This tag requires that the tag GENERATE_QHP is set to YES.
+
+QHG_LOCATION           =
+
+# If the GENERATE_ECLIPSEHELP tag is set to YES, additional index files will be
+# generated, together with the HTML files, they form an Eclipse help plugin. To
+# install this plugin and make it available under the help contents menu in
+# Eclipse, the contents of the directory containing the HTML and XML files needs
+# to be copied into the plugins directory of eclipse. The name of the directory
+# within the plugins directory should be the same as the ECLIPSE_DOC_ID value.
+# After copying Eclipse needs to be restarted before the help appears.
+# The default value is: NO.
+# This tag requires that the tag GENERATE_HTML is set to YES.
+
+GENERATE_ECLIPSEHELP   = NO
+
+# A unique identifier for the Eclipse help plugin. When installing the plugin
+# the directory name containing the HTML and XML files should also have this
+# name. Each documentation set should have its own identifier.
+# The default value is: org.doxygen.Project.
+# This tag requires that the tag GENERATE_ECLIPSEHELP is set to YES.
+
+ECLIPSE_DOC_ID         = org.doxygen.Project
+
+# If you want full control over the layout of the generated HTML pages it might
+# be necessary to disable the index and replace it with your own. The
+# DISABLE_INDEX tag can be used to turn on/off the condensed index (tabs) at top
+# of each HTML page. A value of NO enables the index and the value YES disables
+# it. Since the tabs in the index contain the same information as the navigation
+# tree, you can set this option to YES if you also set GENERATE_TREEVIEW to YES.
+# The default value is: NO.
+# This tag requires that the tag GENERATE_HTML is set to YES.
+
+DISABLE_INDEX          = NO
+
+# The GENERATE_TREEVIEW tag is used to specify whether a tree-like index
+# structure should be generated to display hierarchical information. If the tag
+# value is set to YES, a side panel will be generated containing a tree-like
+# index structure (just like the one that is generated for HTML Help). For this
+# to work a browser that supports JavaScript, DHTML, CSS and frames is required
+# (i.e. any modern browser). Windows users are probably better off using the
+# HTML help feature. Via custom stylesheets (see HTML_EXTRA_STYLESHEET) one can
+# further fine-tune the look of the index. As an example, the default style
+# sheet generated by doxygen has an example that shows how to put an image at
+# the root of the tree instead of the PROJECT_NAME. Since the tree basically has
+# the same information as the tab index, you could consider setting
+# DISABLE_INDEX to YES when enabling this option.
+# The default value is: NO.
+# This tag requires that the tag GENERATE_HTML is set to YES.
+
+GENERATE_TREEVIEW      = NO
+
+# The ENUM_VALUES_PER_LINE tag can be used to set the number of enum values that
+# doxygen will group on one line in the generated HTML documentation.
+#
+# Note that a value of 0 will completely suppress the enum values from appearing
+# in the overview section.
+# Minimum value: 0, maximum value: 20, default value: 4.
+# This tag requires that the tag GENERATE_HTML is set to YES.
+
+ENUM_VALUES_PER_LINE   = 4
+
+# If the treeview is enabled (see GENERATE_TREEVIEW) then this tag can be used
+# to set the initial width (in pixels) of the frame in which the tree is shown.
+# Minimum value: 0, maximum value: 1500, default value: 250.
+# This tag requires that the tag GENERATE_HTML is set to YES.
+
+TREEVIEW_WIDTH         = 250
+
+# When the EXT_LINKS_IN_WINDOW option is set to YES doxygen will open links to
+# external symbols imported via tag files in a separate window.
+# The default value is: NO.
+# This tag requires that the tag GENERATE_HTML is set to YES.
+
+EXT_LINKS_IN_WINDOW    = NO
+
+# Use this tag to change the font size of LaTeX formulas included as images in
+# the HTML documentation. When you change the font size after a successful
+# doxygen run you need to manually remove any form_*.png images from the HTML
+# output directory to force them to be regenerated.
+# Minimum value: 8, maximum value: 50, default value: 10.
+# This tag requires that the tag GENERATE_HTML is set to YES.
+
+FORMULA_FONTSIZE       = 10
+
+# Use the FORMULA_TRANPARENT tag to determine whether or not the images
+# generated for formulas are transparent PNGs. Transparent PNGs are not
+# supported properly for IE 6.0, but are supported on all modern browsers.
+#
+# Note that when changing this option you need to delete any form_*.png files in
+# the HTML output directory before the changes have effect.
+# The default value is: YES.
+# This tag requires that the tag GENERATE_HTML is set to YES.
+
+FORMULA_TRANSPARENT    = YES
+
+# Enable the USE_MATHJAX option to render LaTeX formulas using MathJax (see
+# http://www.mathjax.org) which uses client side Javascript for the rendering
+# instead of using prerendered bitmaps. Use this if you do not have LaTeX
+# installed or if you want to formulas look prettier in the HTML output. When
+# enabled you may also need to install MathJax separately and configure the path
+# to it using the MATHJAX_RELPATH option.
+# The default value is: NO.
+# This tag requires that the tag GENERATE_HTML is set to YES.
+
+USE_MATHJAX            = NO
+
+# When MathJax is enabled you can set the default output format to be used for
+# the MathJax output. See the MathJax site (see:
+# http://docs.mathjax.org/en/latest/output.html) for more details.
+# Possible values are: HTML-CSS (which is slower, but has the best
+# compatibility), NativeMML (i.e. MathML) and SVG.
+# The default value is: HTML-CSS.
+# This tag requires that the tag USE_MATHJAX is set to YES.
+
+MATHJAX_FORMAT         = HTML-CSS
+
+# When MathJax is enabled you need to specify the location relative to the HTML
+# output directory using the MATHJAX_RELPATH option. The destination directory
+# should contain the MathJax.js script. For instance, if the mathjax directory
+# is located at the same level as the HTML output directory, then
+# MATHJAX_RELPATH should be ../mathjax. The default value points to the MathJax
+# Content Delivery Network so you can quickly see the result without installing
+# MathJax. However, it is strongly recommended to install a local copy of
+# MathJax from http://www.mathjax.org before deployment.
+# The default value is: http://cdn.mathjax.org/mathjax/latest.
+# This tag requires that the tag USE_MATHJAX is set to YES.
+
+MATHJAX_RELPATH        = http://cdn.mathjax.org/mathjax/latest
+
+# The MATHJAX_EXTENSIONS tag can be used to specify one or more MathJax
+# extension names that should be enabled during MathJax rendering. For example
+# MATHJAX_EXTENSIONS = TeX/AMSmath TeX/AMSsymbols
+# This tag requires that the tag USE_MATHJAX is set to YES.
+
+MATHJAX_EXTENSIONS     =
+
+# The MATHJAX_CODEFILE tag can be used to specify a file with javascript pieces
+# of code that will be used on startup of the MathJax code. See the MathJax site
+# (see: http://docs.mathjax.org/en/latest/output.html) for more details. For an
+# example see the documentation.
+# This tag requires that the tag USE_MATHJAX is set to YES.
+
+MATHJAX_CODEFILE       =
+
+# When the SEARCHENGINE tag is enabled doxygen will generate a search box for
+# the HTML output. The underlying search engine uses javascript and DHTML and
+# should work on any modern browser. Note that when using HTML help
+# (GENERATE_HTMLHELP), Qt help (GENERATE_QHP), or docsets (GENERATE_DOCSET)
+# there is already a search function so this one should typically be disabled.
+# For large projects the javascript based search engine can be slow, then
+# enabling SERVER_BASED_SEARCH may provide a better solution. It is possible to
+# search using the keyboard; to jump to the search box use <access key> + S
+# (what the <access key> is depends on the OS and browser, but it is typically
+# <CTRL>, <ALT>/<option>, or both). Inside the search box use the <cursor down
+# key> to jump into the search results window, the results can be navigated
+# using the <cursor keys>. Press <Enter> to select an item or <escape> to cancel
+# the search. The filter options can be selected when the cursor is inside the
+# search box by pressing <Shift>+<cursor down>. Also here use the <cursor keys>
+# to select a filter and <Enter> or <escape> to activate or cancel the filter
+# option.
+# The default value is: YES.
+# This tag requires that the tag GENERATE_HTML is set to YES.
+
+SEARCHENGINE           = YES
+
+# When the SERVER_BASED_SEARCH tag is enabled the search engine will be
+# implemented using a web server instead of a web client using Javascript. There
+# are two flavours of web server based searching depending on the
+# EXTERNAL_SEARCH setting. When disabled, doxygen will generate a PHP script for
+# searching and an index file used by the script. When EXTERNAL_SEARCH is
+# enabled the indexing and searching needs to be provided by external tools. See
+# the section "External Indexing and Searching" for details.
+# The default value is: NO.
+# This tag requires that the tag SEARCHENGINE is set to YES.
+
+SERVER_BASED_SEARCH    = NO
+
+# When EXTERNAL_SEARCH tag is enabled doxygen will no longer generate the PHP
+# script for searching. Instead the search results are written to an XML file
+# which needs to be processed by an external indexer. Doxygen will invoke an
+# external search engine pointed to by the SEARCHENGINE_URL option to obtain the
+# search results.
+#
+# Doxygen ships with an example indexer ( doxyindexer) and search engine
+# (doxysearch.cgi) which are based on the open source search engine library
+# Xapian (see: http://xapian.org/).
+#
+# See the section "External Indexing and Searching" for details.
+# The default value is: NO.
+# This tag requires that the tag SEARCHENGINE is set to YES.
+
+EXTERNAL_SEARCH        = NO
+
+# The SEARCHENGINE_URL should point to a search engine hosted by a web server
+# which will return the search results when EXTERNAL_SEARCH is enabled.
+#
+# Doxygen ships with an example indexer ( doxyindexer) and search engine
+# (doxysearch.cgi) which are based on the open source search engine library
+# Xapian (see: http://xapian.org/). See the section "External Indexing and
+# Searching" for details.
+# This tag requires that the tag SEARCHENGINE is set to YES.
+
+SEARCHENGINE_URL       =
+
+# When SERVER_BASED_SEARCH and EXTERNAL_SEARCH are both enabled the unindexed
+# search data is written to a file for indexing by an external tool. With the
+# SEARCHDATA_FILE tag the name of this file can be specified.
+# The default file is: searchdata.xml.
+# This tag requires that the tag SEARCHENGINE is set to YES.
+
+SEARCHDATA_FILE        = searchdata.xml
+
+# When SERVER_BASED_SEARCH and EXTERNAL_SEARCH are both enabled the
+# EXTERNAL_SEARCH_ID tag can be used as an identifier for the project. This is
+# useful in combination with EXTRA_SEARCH_MAPPINGS to search through multiple
+# projects and redirect the results back to the right project.
+# This tag requires that the tag SEARCHENGINE is set to YES.
+
+EXTERNAL_SEARCH_ID     =
+
+# The EXTRA_SEARCH_MAPPINGS tag can be used to enable searching through doxygen
+# projects other than the one defined by this configuration file, but that are
+# all added to the same external search index. Each project needs to have a
+# unique id set via EXTERNAL_SEARCH_ID. The search mapping then maps the id of
+# to a relative location where the documentation can be found. The format is:
+# EXTRA_SEARCH_MAPPINGS = tagname1=loc1 tagname2=loc2 ...
+# This tag requires that the tag SEARCHENGINE is set to YES.
+
+EXTRA_SEARCH_MAPPINGS  =
+
+#---------------------------------------------------------------------------
+# Configuration options related to the LaTeX output
+#---------------------------------------------------------------------------
+
+# If the GENERATE_LATEX tag is set to YES doxygen will generate LaTeX output.
+# The default value is: YES.
+
+GENERATE_LATEX         = NO
+
+# The LATEX_OUTPUT tag is used to specify where the LaTeX docs will be put. If a
+# relative path is entered the value of OUTPUT_DIRECTORY will be put in front of
+# it.
+# The default directory is: latex.
+# This tag requires that the tag GENERATE_LATEX is set to YES.
+
+LATEX_OUTPUT           = latex
+
+# The LATEX_CMD_NAME tag can be used to specify the LaTeX command name to be
+# invoked.
+#
+# Note that when enabling USE_PDFLATEX this option is only used for generating
+# bitmaps for formulas in the HTML output, but not in the Makefile that is
+# written to the output directory.
+# The default file is: latex.
+# This tag requires that the tag GENERATE_LATEX is set to YES.
+
+LATEX_CMD_NAME         = latex
+
+# The MAKEINDEX_CMD_NAME tag can be used to specify the command name to generate
+# index for LaTeX.
+# The default file is: makeindex.
+# This tag requires that the tag GENERATE_LATEX is set to YES.
+
+MAKEINDEX_CMD_NAME     = makeindex
+
+# If the COMPACT_LATEX tag is set to YES doxygen generates more compact LaTeX
+# documents. This may be useful for small projects and may help to save some
+# trees in general.
+# The default value is: NO.
+# This tag requires that the tag GENERATE_LATEX is set to YES.
+
+COMPACT_LATEX          = NO
+
+# The PAPER_TYPE tag can be used to set the paper type that is used by the
+# printer.
+# Possible values are: a4 (210 x 297 mm), letter (8.5 x 11 inches), legal (8.5 x
+# 14 inches) and executive (7.25 x 10.5 inches).
+# The default value is: a4.
+# This tag requires that the tag GENERATE_LATEX is set to YES.
+
+PAPER_TYPE             = a4
+
+# The EXTRA_PACKAGES tag can be used to specify one or more LaTeX package names
+# that should be included in the LaTeX output. To get the times font for
+# instance you can specify
+# EXTRA_PACKAGES=times
+# If left blank no extra packages will be included.
+# This tag requires that the tag GENERATE_LATEX is set to YES.
+
+EXTRA_PACKAGES         =
+
+# The LATEX_HEADER tag can be used to specify a personal LaTeX header for the
+# generated LaTeX document. The header should contain everything until the first
+# chapter. If it is left blank doxygen will generate a standard header. See
+# section "Doxygen usage" for information on how to let doxygen write the
+# default header to a separate file.
+#
+# Note: Only use a user-defined header if you know what you are doing! The
+# following commands have a special meaning inside the header: $title,
+# $datetime, $date, $doxygenversion, $projectname, $projectnumber. Doxygen will
+# replace them by respectively the title of the page, the current date and time,
+# only the current date, the version number of doxygen, the project name (see
+# PROJECT_NAME), or the project number (see PROJECT_NUMBER).
+# This tag requires that the tag GENERATE_LATEX is set to YES.
+
+LATEX_HEADER           =
+
+# The LATEX_FOOTER tag can be used to specify a personal LaTeX footer for the
+# generated LaTeX document. The footer should contain everything after the last
+# chapter. If it is left blank doxygen will generate a standard footer.
+#
+# Note: Only use a user-defined footer if you know what you are doing!
+# This tag requires that the tag GENERATE_LATEX is set to YES.
+
+LATEX_FOOTER           =
+
+# The LATEX_EXTRA_FILES tag can be used to specify one or more extra images or
+# other source files which should be copied to the LATEX_OUTPUT output
+# directory. Note that the files will be copied as-is; there are no commands or
+# markers available.
+# This tag requires that the tag GENERATE_LATEX is set to YES.
+
+LATEX_EXTRA_FILES      =
+
+# If the PDF_HYPERLINKS tag is set to YES, the LaTeX that is generated is
+# prepared for conversion to PDF (using ps2pdf or pdflatex). The PDF file will
+# contain links (just like the HTML output) instead of page references. This
+# makes the output suitable for online browsing using a PDF viewer.
+# The default value is: YES.
+# This tag requires that the tag GENERATE_LATEX is set to YES.
+
+PDF_HYPERLINKS         = YES
+
+# If the LATEX_PDFLATEX tag is set to YES, doxygen will use pdflatex to generate
+# the PDF file directly from the LaTeX files. Set this option to YES to get a
+# higher quality PDF documentation.
+# The default value is: YES.
+# This tag requires that the tag GENERATE_LATEX is set to YES.
+
+USE_PDFLATEX           = YES
+
+# If the LATEX_BATCHMODE tag is set to YES, doxygen will add the \batchmode
+# command to the generated LaTeX files. This will instruct LaTeX to keep running
+# if errors occur, instead of asking the user for help. This option is also used
+# when generating formulas in HTML.
+# The default value is: NO.
+# This tag requires that the tag GENERATE_LATEX is set to YES.
+
+LATEX_BATCHMODE        = NO
+
+# If the LATEX_HIDE_INDICES tag is set to YES then doxygen will not include the
+# index chapters (such as File Index, Compound Index, etc.) in the output.
+# The default value is: NO.
+# This tag requires that the tag GENERATE_LATEX is set to YES.
+
+LATEX_HIDE_INDICES     = NO
+
+# If the LATEX_SOURCE_CODE tag is set to YES then doxygen will include source
+# code with syntax highlighting in the LaTeX output.
+#
+# Note that which sources are shown also depends on other settings such as
+# SOURCE_BROWSER.
+# The default value is: NO.
+# This tag requires that the tag GENERATE_LATEX is set to YES.
+
+LATEX_SOURCE_CODE      = NO
+
+# The LATEX_BIB_STYLE tag can be used to specify the style to use for the
+# bibliography, e.g. plainnat, or ieeetr. See
+# http://en.wikipedia.org/wiki/BibTeX and \cite for more info.
+# The default value is: plain.
+# This tag requires that the tag GENERATE_LATEX is set to YES.
+
+LATEX_BIB_STYLE        = plain
+
+#---------------------------------------------------------------------------
+# Configuration options related to the RTF output
+#---------------------------------------------------------------------------
+
+# If the GENERATE_RTF tag is set to YES doxygen will generate RTF output. The
+# RTF output is optimized for Word 97 and may not look too pretty with other RTF
+# readers/editors.
+# The default value is: NO.
+
+GENERATE_RTF           = NO
+
+# The RTF_OUTPUT tag is used to specify where the RTF docs will be put. If a
+# relative path is entered the value of OUTPUT_DIRECTORY will be put in front of
+# it.
+# The default directory is: rtf.
+# This tag requires that the tag GENERATE_RTF is set to YES.
+
+RTF_OUTPUT             = rtf
+
+# If the COMPACT_RTF tag is set to YES doxygen generates more compact RTF
+# documents. This may be useful for small projects and may help to save some
+# trees in general.
+# The default value is: NO.
+# This tag requires that the tag GENERATE_RTF is set to YES.
+
+COMPACT_RTF            = NO
+
+# If the RTF_HYPERLINKS tag is set to YES, the RTF that is generated will
+# contain hyperlink fields. The RTF file will contain links (just like the HTML
+# output) instead of page references. This makes the output suitable for online
+# browsing using Word or some other Word compatible readers that support those
+# fields.
+#
+# Note: WordPad (write) and others do not support links.
+# The default value is: NO.
+# This tag requires that the tag GENERATE_RTF is set to YES.
+
+RTF_HYPERLINKS         = NO
+
+# Load stylesheet definitions from file. Syntax is similar to doxygen's config
+# file, i.e. a series of assignments. You only have to provide replacements,
+# missing definitions are set to their default value.
+#
+# See also section "Doxygen usage" for information on how to generate the
+# default style sheet that doxygen normally uses.
+# This tag requires that the tag GENERATE_RTF is set to YES.
+
+RTF_STYLESHEET_FILE    =
+
+# Set optional variables used in the generation of an RTF document. Syntax is
+# similar to doxygen's config file. A template extensions file can be generated
+# using doxygen -e rtf extensionFile.
+# This tag requires that the tag GENERATE_RTF is set to YES.
+
+RTF_EXTENSIONS_FILE    =
+
+#---------------------------------------------------------------------------
+# Configuration options related to the man page output
+#---------------------------------------------------------------------------
+
+# If the GENERATE_MAN tag is set to YES doxygen will generate man pages for
+# classes and files.
+# The default value is: NO.
+
+GENERATE_MAN           = NO
+
+# The MAN_OUTPUT tag is used to specify where the man pages will be put. If a
+# relative path is entered the value of OUTPUT_DIRECTORY will be put in front of
+# it. A directory man3 will be created inside the directory specified by
+# MAN_OUTPUT.
+# The default directory is: man.
+# This tag requires that the tag GENERATE_MAN is set to YES.
+
+MAN_OUTPUT             = man
+
+# The MAN_EXTENSION tag determines the extension that is added to the generated
+# man pages. In case the manual section does not start with a number, the number
+# 3 is prepended. The dot (.) at the beginning of the MAN_EXTENSION tag is
+# optional.
+# The default value is: .3.
+# This tag requires that the tag GENERATE_MAN is set to YES.
+
+MAN_EXTENSION          = .3
+
+# If the MAN_LINKS tag is set to YES and doxygen generates man output, then it
+# will generate one additional man file for each entity documented in the real
+# man page(s). These additional files only source the real man page, but without
+# them the man command would be unable to find the correct page.
+# The default value is: NO.
+# This tag requires that the tag GENERATE_MAN is set to YES.
+
+MAN_LINKS              = NO
+
+#---------------------------------------------------------------------------
+# Configuration options related to the XML output
+#---------------------------------------------------------------------------
+
+# If the GENERATE_XML tag is set to YES doxygen will generate an XML file that
+# captures the structure of the code including all documentation.
+# The default value is: NO.
+
+GENERATE_XML           = YES
+
+# The XML_OUTPUT tag is used to specify where the XML pages will be put. If a
+# relative path is entered the value of OUTPUT_DIRECTORY will be put in front of
+# it.
+# The default directory is: xml.
+# This tag requires that the tag GENERATE_XML is set to YES.
+
+XML_OUTPUT             = xml
+
+# If the XML_PROGRAMLISTING tag is set to YES doxygen will dump the program
+# listings (including syntax highlighting and cross-referencing information) to
+# the XML output. Note that enabling this will significantly increase the size
+# of the XML output.
+# The default value is: YES.
+# This tag requires that the tag GENERATE_XML is set to YES.
+
+XML_PROGRAMLISTING     = YES
+
+#---------------------------------------------------------------------------
+# Configuration options related to the DOCBOOK output
+#---------------------------------------------------------------------------
+
+# If the GENERATE_DOCBOOK tag is set to YES doxygen will generate Docbook files
+# that can be used to generate PDF.
+# The default value is: NO.
+
+GENERATE_DOCBOOK       = NO
+
+# The DOCBOOK_OUTPUT tag is used to specify where the Docbook pages will be put.
+# If a relative path is entered the value of OUTPUT_DIRECTORY will be put in
+# front of it.
+# The default directory is: docbook.
+# This tag requires that the tag GENERATE_DOCBOOK is set to YES.
+
+DOCBOOK_OUTPUT         = docbook
+
+#---------------------------------------------------------------------------
+# Configuration options for the AutoGen Definitions output
+#---------------------------------------------------------------------------
+
+# If the GENERATE_AUTOGEN_DEF tag is set to YES doxygen will generate an AutoGen
+# Definitions (see http://autogen.sf.net) file that captures the structure of
+# the code including all documentation. Note that this feature is still
+# experimental and incomplete at the moment.
+# The default value is: NO.
+
+GENERATE_AUTOGEN_DEF   = NO
+
+#---------------------------------------------------------------------------
+# Configuration options related to the Perl module output
+#---------------------------------------------------------------------------
+
+# If the GENERATE_PERLMOD tag is set to YES doxygen will generate a Perl module
+# file that captures the structure of the code including all documentation.
+#
+# Note that this feature is still experimental and incomplete at the moment.
+# The default value is: NO.
+
+GENERATE_PERLMOD       = NO
+
+# If the PERLMOD_LATEX tag is set to YES doxygen will generate the necessary
+# Makefile rules, Perl scripts and LaTeX code to be able to generate PDF and DVI
+# output from the Perl module output.
+# The default value is: NO.
+# This tag requires that the tag GENERATE_PERLMOD is set to YES.
+
+PERLMOD_LATEX          = NO
+
+# If the PERLMOD_PRETTY tag is set to YES the Perl module output will be nicely
+# formatted so it can be parsed by a human reader. This is useful if you want to
+# understand what is going on. On the other hand, if this tag is set to NO the
+# size of the Perl module output will be much smaller and Perl will parse it
+# just the same.
+# The default value is: YES.
+# This tag requires that the tag GENERATE_PERLMOD is set to YES.
+
+PERLMOD_PRETTY         = YES
+
+# The names of the make variables in the generated doxyrules.make file are
+# prefixed with the string contained in PERLMOD_MAKEVAR_PREFIX. This is useful
+# so different doxyrules.make files included by the same Makefile don't
+# overwrite each other's variables.
+# This tag requires that the tag GENERATE_PERLMOD is set to YES.
+
+PERLMOD_MAKEVAR_PREFIX =
+
+#---------------------------------------------------------------------------
+# Configuration options related to the preprocessor
+#---------------------------------------------------------------------------
+
+# If the ENABLE_PREPROCESSING tag is set to YES doxygen will evaluate all
+# C-preprocessor directives found in the sources and include files.
+# The default value is: YES.
+
+ENABLE_PREPROCESSING   = YES
+
+# If the MACRO_EXPANSION tag is set to YES doxygen will expand all macro names
+# in the source code. If set to NO only conditional compilation will be
+# performed. Macro expansion can be done in a controlled way by setting
+# EXPAND_ONLY_PREDEF to YES.
+# The default value is: NO.
+# This tag requires that the tag ENABLE_PREPROCESSING is set to YES.
+
+MACRO_EXPANSION        = YES
+
+# If the EXPAND_ONLY_PREDEF and MACRO_EXPANSION tags are both set to YES then
+# the macro expansion is limited to the macros specified with the PREDEFINED and
+# EXPAND_AS_DEFINED tags.
+# The default value is: NO.
+# This tag requires that the tag ENABLE_PREPROCESSING is set to YES.
+
+EXPAND_ONLY_PREDEF     = NO
+
+# If the SEARCH_INCLUDES tag is set to YES the includes files in the
+# INCLUDE_PATH will be searched if a #include is found.
+# The default value is: YES.
+# This tag requires that the tag ENABLE_PREPROCESSING is set to YES.
+
+SEARCH_INCLUDES        = YES
+
+# The INCLUDE_PATH tag can be used to specify one or more directories that
+# contain include files that are not input files but should be processed by the
+# preprocessor.
+# This tag requires that the tag SEARCH_INCLUDES is set to YES.
+
+INCLUDE_PATH           =
+
+# You can use the INCLUDE_FILE_PATTERNS tag to specify one or more wildcard
+# patterns (like *.h and *.hpp) to filter out the header-files in the
+# directories. If left blank, the patterns specified with FILE_PATTERNS will be
+# used.
+# This tag requires that the tag ENABLE_PREPROCESSING is set to YES.
+
+INCLUDE_FILE_PATTERNS  =
+
+# The PREDEFINED tag can be used to specify one or more macro names that are
+# defined before the preprocessor is started (similar to the -D option of e.g.
+# gcc). The argument of the tag is a list of macros of the form: name or
+# name=definition (no spaces). If the definition and the "=" are omitted, "=1"
+# is assumed. To prevent a macro definition from being undefined via #undef or
+# recursively expanded use the := operator instead of the = operator.
+# This tag requires that the tag ENABLE_PREPROCESSING is set to YES.
+
+PREDEFINED = IXION_DLLPUBLIC IXION_DLLPUBLIC_VAR IXION_DEPRECATED
+
+# If the MACRO_EXPANSION and EXPAND_ONLY_PREDEF tags are set to YES then this
+# tag can be used to specify a list of macro names that should be expanded. The
+# macro definition that is found in the sources will be used. Use the PREDEFINED
+# tag if you want to use a different macro definition that overrules the
+# definition found in the source code.
+# This tag requires that the tag ENABLE_PREPROCESSING is set to YES.
+
+EXPAND_AS_DEFINED      =
+
+# If the SKIP_FUNCTION_MACROS tag is set to YES then doxygen's preprocessor will
+# remove all refrences to function-like macros that are alone on a line, have an
+# all uppercase name, and do not end with a semicolon. Such function macros are
+# typically used for boiler-plate code, and will confuse the parser if not
+# removed.
+# The default value is: YES.
+# This tag requires that the tag ENABLE_PREPROCESSING is set to YES.
+
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+# If the INCLUDE_GRAPH, ENABLE_PREPROCESSING and SEARCH_INCLUDES tags are set to
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+# dependency graph for every global function or class method.
+#
+# Note that enabling this option will significantly increase the time of a run.
+# So in most cases it will be better to enable call graphs for selected
+# functions only using the \callgraph command.
+# The default value is: NO.
+# This tag requires that the tag HAVE_DOT is set to YES.
+
+CALL_GRAPH             = NO
+
+# If the CALLER_GRAPH tag is set to YES then doxygen will generate a caller
+# dependency graph for every global function or class method.
+#
+# Note that enabling this option will significantly increase the time of a run.
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+# functions only using the \callergraph command.
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+
+CALLER_GRAPH           = NO
+
+# If the GRAPHICAL_HIERARCHY tag is set to YES then doxygen will graphical
+# hierarchy of all classes instead of a textual one.
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+
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+# If the DIRECTORY_GRAPH tag is set to YES then doxygen will show the
+# dependencies a directory has on other directories in a graphical way. The
+# dependency relations are determined by the #include relations between the
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+
+DIRECTORY_GRAPH        = YES
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+# Note: If you choose svg you need to set HTML_FILE_EXTENSION to xhtml in order
+# to make the SVG files visible in IE 9+ (other browsers do not have this
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+
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+
+# If DOT_IMAGE_FORMAT is set to svg, then this option can be set to YES to
+# enable generation of interactive SVG images that allow zooming and panning.
+#
+# Note that this requires a modern browser other than Internet Explorer. Tested
+# and working are Firefox, Chrome, Safari, and Opera.
+# Note: For IE 9+ you need to set HTML_FILE_EXTENSION to xhtml in order to make
+# the SVG files visible. Older versions of IE do not have SVG support.
+# The default value is: NO.
+# This tag requires that the tag HAVE_DOT is set to YES.
+
+INTERACTIVE_SVG        = NO
+
+# The DOT_PATH tag can be used to specify the path where the dot tool can be
+# found. If left blank, it is assumed the dot tool can be found in the path.
+# This tag requires that the tag HAVE_DOT is set to YES.
+
+DOT_PATH               =
+
+# The DOTFILE_DIRS tag can be used to specify one or more directories that
+# contain dot files that are included in the documentation (see the \dotfile
+# command).
+# This tag requires that the tag HAVE_DOT is set to YES.
+
+DOTFILE_DIRS           =
+
+# The MSCFILE_DIRS tag can be used to specify one or more directories that
+# contain msc files that are included in the documentation (see the \mscfile
+# command).
+
+MSCFILE_DIRS           =
+
+# The DIAFILE_DIRS tag can be used to specify one or more directories that
+# contain dia files that are included in the documentation (see the \diafile
+# command).
+
+DIAFILE_DIRS           =
+
+# The DOT_GRAPH_MAX_NODES tag can be used to set the maximum number of nodes
+# that will be shown in the graph. If the number of nodes in a graph becomes
+# larger than this value, doxygen will truncate the graph, which is visualized
+# by representing a node as a red box. Note that doxygen if the number of direct
+# children of the root node in a graph is already larger than
+# DOT_GRAPH_MAX_NODES then the graph will not be shown at all. Also note that
+# the size of a graph can be further restricted by MAX_DOT_GRAPH_DEPTH.
+# Minimum value: 0, maximum value: 10000, default value: 50.
+# This tag requires that the tag HAVE_DOT is set to YES.
+
+DOT_GRAPH_MAX_NODES    = 50
+
+# The MAX_DOT_GRAPH_DEPTH tag can be used to set the maximum depth of the graphs
+# generated by dot. A depth value of 3 means that only nodes reachable from the
+# root by following a path via at most 3 edges will be shown. Nodes that lay
+# further from the root node will be omitted. Note that setting this option to 1
+# or 2 may greatly reduce the computation time needed for large code bases. Also
+# note that the size of a graph can be further restricted by
+# DOT_GRAPH_MAX_NODES. Using a depth of 0 means no depth restriction.
+# Minimum value: 0, maximum value: 1000, default value: 0.
+# This tag requires that the tag HAVE_DOT is set to YES.
+
+MAX_DOT_GRAPH_DEPTH    = 0
+
+# Set the DOT_TRANSPARENT tag to YES to generate images with a transparent
+# background. This is disabled by default, because dot on Windows does not seem
+# to support this out of the box.
+#
+# Warning: Depending on the platform used, enabling this option may lead to
+# badly anti-aliased labels on the edges of a graph (i.e. they become hard to
+# read).
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+# This tag requires that the tag HAVE_DOT is set to YES.
+
+DOT_TRANSPARENT        = NO
+
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+# files in one run (i.e. multiple -o and -T options on the command line). This
+# makes dot run faster, but since only newer versions of dot (>1.8.10) support
+# this, this feature is disabled by default.
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+
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+# explaining the meaning of the various boxes and arrows in the dot generated
+# graphs.
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+
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+DOT_CLEANUP            = YES
diff --git a/doc/environment.yml b/doc/environment.yml
new file mode 100644
index 0000000..0c2722c
--- /dev/null
+++ b/doc/environment.yml
@@ -0,0 +1,8 @@
+name: RTD
+channels:
+  - conda-forge
+  - defaults
+dependencies:
+  - python=3.8
+  - doxygen>=1.9.1
+  - breathe
diff --git a/doc/index.rst b/doc/index.rst
new file mode 100644
index 0000000..b8cfafc
--- /dev/null
+++ b/doc/index.rst
@@ -0,0 +1,29 @@
+.. Ixion documentation master file, created by
+   sphinx-quickstart on Wed Feb 11 21:33:47 2015.
+   You can adapt this file completely to your liking, but it should at least
+   contain the root `toctree` directive.
+
+Ixion library documentation
+===========================
+
+Ixion is a general purpose formula parser, interpreter, formula cell dependency
+tracker and spreadsheet document model backend all in one package.  You can use
+Ixion to build a formula engine backend with spreadsheet-like multi-sheet cell
+storage management, or simply use to handle parsing and tokenization of formula
+expressions.
+
+Contents:
+
+.. toctree::
+   :maxdepth: 2
+
+   overview/index.rst
+   cpp/index.rst
+   python/index.rst
+
+Indices and tables
+==================
+
+* :ref:`genindex`
+* :ref:`search`
+
diff --git a/doc/overview/index.rst b/doc/overview/index.rst
new file mode 100644
index 0000000..aee0737
--- /dev/null
+++ b/doc/overview/index.rst
@@ -0,0 +1,19 @@
+
+Overview
+========
+
+Project repository
+------------------
+
+Ixion project's main repository is hosted in GitLab: https://gitlab.com/ixion/ixion.
+
+
+Installation
+------------
+
+From the repository
+^^^^^^^^^^^^^^^^^^^
+
+Please follow the instructions found on the project repository page to build
+and install directly from the repository.
+
diff --git a/doc/python/document.rst b/doc/python/document.rst
new file mode 100644
index 0000000..7171f2c
--- /dev/null
+++ b/doc/python/document.rst
@@ -0,0 +1,58 @@
+
+.. py:currentmodule:: ixion
+
+Document
+========
+
+.. class:: Document()
+
+   Class :class:`~ixion.Document` represents an entire document which consists
+   of one or more :class:`~ixion.Sheet` objects.
+
+.. attribute:: Document.sheet_names
+
+   A read-only attribute that provides a tuple of the names of the sheets that
+   belong to the document. The order of the sheet names signifies the order
+   of the sheets in the document.
+
+.. method:: Document.append_sheet(sheet_name)
+
+   Append a new sheet to the document object and return the newly created
+   :class:`~ixion.Sheet` object. The *sheet name* will become the name of the
+   sheet object being appended. Each :class:`Sheet` object must have a name,
+   and the name must be unique within the document.
+
+   :param str sheet_name: name of the sheet to be appended to the document.
+   :rtype: :class:`ixion.Sheet`
+   :return: appended sheet object.
+
+.. method:: Document.get_sheet(arg)
+
+   Get a sheet object either by the position or by the name.  When the ``arg``
+   is an integer, it returns the sheet object at specified position (0-based).
+   When the ``arg`` is a string, it returns the sheet object whose name
+   matches the specified string.
+
+   :param arg: either the name of a sheet if it's of type ``str``, or the
+      index of a sheet if it's of type ``int``.
+   :rtype: :class:`ixion.Sheet`
+   :return: sheet object representing the specified sheet.
+
+.. warning:: Prefer passing a sheet index to :meth:`~ixion.Document.get_sheet`
+             than passing a sheet name.  When passing a sheet name as an
+             argument, the current :meth:`~ixion.Document.get_sheet`
+             implementation has to iterate through the sheet objects in the
+             document to find a matching one.
+
+.. method:: Document.calculate([threads])
+
+   Calculate all formula cells within the document that are marked "dirty" i.e.
+   either those formula cells whose direct or indirect references have changed
+   their values, or those formula cells that have been entered into the
+   document.
+
+   :param int threads: (optional) number of threads to use for the calculation
+      besides the main thread.  Set this to 0 if you want the calculation to
+      be performed on the main thread only.  The value of 0 is assumed if this
+      value is not specified.
+
diff --git a/doc/python/index.rst b/doc/python/index.rst
new file mode 100644
index 0000000..9efcad2
--- /dev/null
+++ b/doc/python/index.rst
@@ -0,0 +1,11 @@
+
+Python API
+==========
+
+.. toctree::
+   :maxdepth: 2
+
+   quickstart.rst
+   document.rst
+   sheet.rst
+
diff --git a/doc/python/quickstart.rst b/doc/python/quickstart.rst
new file mode 100644
index 0000000..6b44e0f
--- /dev/null
+++ b/doc/python/quickstart.rst
@@ -0,0 +1,85 @@
+
+.. py:currentmodule:: ixion
+
+Quickstart
+==========
+
+Let's go over very quickly how to create a document and populate some cells inside spreadsheet.
+
+First, you need to import ixion module and create a new :class:`Document` object.
+
+::
+
+    >>> import ixion
+    >>> doc = ixion.Document()
+
+Since your newly-created document has no sheet at all, you need to insert one.
+
+::
+
+    >>> sheet1 = doc.append_sheet("MySheet1")
+
+The :meth:`Document.append_sheet` method takes a sheet name string as an argument (which in
+this case is "MySheet1") and returns an object representing the sheet that has
+just been inserted.  This sheet object allows access to the sheet
+name via the :attr:`Sheet.name` attribute.
+
+::
+
+    >>> print(sheet1.name)
+    'MySheet1'
+
+.. note:: This attribute is read-only; you'll get a :exc:`TypeError` if you
+          attempt to assign a new value to it.
+
+Now that you have a sheet object, let's go over how to put new cell values into
+the sheet.  The sheet object provides several methods to set new cell values
+and also to retrieve them afterward.
+
+::
+
+    >>> sheet1.set_numeric_cell(0, 0, 12.3)  # Set 12.3 to cell A1.
+    >>> sheet1.get_numeric_value(0, 0)
+    12.3
+    >>> sheet1.set_string_cell(1, 0, "My string")  # Set "My string" to cell A2.
+    >>> sheet1.get_string_value(1, 0)
+    'My string'
+
+The setters take 3 arguments: the first one is a 0-based row index, the second
+one is a column index (also 0-based), and the third one is the new cell value.
+You can also pass these arguments by name as follows:
+
+::
+
+    >>> sheet1.set_string_cell(row=1, column=0, value="My string")
+
+Let's insert a formula expression next.
+
+::
+
+    >>> sheet1.set_formula_cell(0, 1, "A1*100")  # B1
+    >>> sheet1.set_formula_cell(1, 1, "A2")      # B2
+
+.. note:: When setting a formula expression to a cell, you don't need to start
+          your formula expression with a '=' like you would when you are
+          entering a formula in a spreadsheet application.
+
+The formula cells don't get calculated automatically as you enter them;
+you need to explicitly tell the document to calculate the formula cells via
+the :meth:`Document.calculate` method.
+
+::
+
+    >>> doc.calculate()
+
+Now all the formula cells in this document have been calculated.  Let's retrieve
+the results of the formula cells.
+
+::
+
+   >>> sheet1.get_numeric_value(0, 1)
+   1230.0
+   >>> sheet1.get_string_value(1, 1)
+   'My string'
+
+That's all there is to it!
diff --git a/doc/python/sheet.rst b/doc/python/sheet.rst
new file mode 100644
index 0000000..74f4ab4
--- /dev/null
+++ b/doc/python/sheet.rst
@@ -0,0 +1,83 @@
+
+.. py:currentmodule:: ixion
+
+Sheet
+=====
+
+.. class:: ixion.Sheet()
+
+   Class :class:`~ixion.Sheet` represents a single sheet that stores cells in
+   a 2-dimensional grid address space.  Rows and columns are used to specify a
+   position in the grid, and both rows and columns are 0-based, with the
+   top-left-most cell having the address of row 0 and column 0.
+
+.. attribute:: Sheet.name
+
+   A string representing the name of the sheet object.  This is a read-only
+   attribute.
+
+.. method:: Sheet.set_numeric_cell(row, column, value)
+
+   Set a numeric *value* to a cell at specified *row* and *column* position.
+
+   :param int row: row position.
+   :param int column: column position.
+   :param float value: numeric value to set to the specified position.
+
+.. method:: Sheet.set_string_cell(row, column, value)
+
+   Set a string *value* to a cell at specified *row* and *column* position.
+
+   :param int row: row position.
+   :param int column: column position.
+   :param str value: string value to set to the specified position.
+
+.. method:: Sheet.set_formula_cell(row, column, value)
+
+   Set a formula expression (*value*) to a cell at specified *row* and *column* position.
+
+   :param int row: row position.
+   :param int column: column position.
+   :param str value: formula expression to set to the specified position.
+
+.. method:: Sheet.get_numeric_value(row, column)
+
+   Get a numeric value representing the content of a cell at specified *row*
+   and *column* position.  If the cell is of numeric type, its value is
+   returned.  If it's a formula cell, the result of the calculated formula
+   result is returned if the result is of numeric type.
+
+   :param int row: row position.
+   :param int column: column position.
+   :rtype: float
+   :return: numeric value of the cell at specified position.
+
+.. method:: Sheet.get_string_value(row, column)
+
+   Get a string value representing the content of a cell at specified *row*
+   and *column* position.  If the cell is of string type, its value is
+   returned as-is.  If it's a formula cell, the result of the calculated
+   formula result is returned if the result is of string type.
+
+   :param int row: row position.
+   :param int column: column position.
+   :rtype: str
+   :return: string value of the cell at specified position.
+
+.. method:: Sheet.get_formula_expression(row, column)
+
+   Given a formula cell at specified *row* and *column* position, get the
+   formula expression stored in that cell.
+
+   :param int row: row position.
+   :param int column: column position.
+   :rtype: str
+   :return: formula expression stored in the cell at specified position.
+
+.. method:: Sheet.erase_cell(row, column)
+
+   Erase the cell at specified *row* and *column* position.  The slot at the
+   specified position becomes empty afterward.
+
+   :param int row: row position.
+   :param int column: column position.
diff --git a/doc/requirements.txt b/doc/requirements.txt
new file mode 100644
index 0000000..cd6467e
--- /dev/null
+++ b/doc/requirements.txt
@@ -0,0 +1 @@
+breathe