Add NULLPTR macro for use in doxygen comments

For the c++ api dox this expands to "\c nullptr" (the
\c directive indicates a code literal value), and for sipify/Python
it expands to ``None`` (`` is sphinx annotation for literal values)

Makes for nicer dox for both c++ and Python!

cmake_templates/Doxyfile.in

@@ -898,7 +898,7 @@ IMAGE_PATH             =
 # need to set EXTENSION_MAPPING for the extension otherwise the files are not
 # properly processed by doxygen.
 
-INPUT_FILTER           = "sed -e 's/TRUE/\\c true/' -e 's/FALSE/\\c false/'"
+INPUT_FILTER           = "sed -e 's/TRUE/\\c true/' -e 's/FALSE/\\c false/'" -e 's/NULLPTR/\\c nullptr/'"
 
 # 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

python/3d/auto_generated/qgsrulebased3drenderer.sip.in

@@ -75,7 +75,7 @@ Similar to rule-based 2D renderer and rule-based labeling, it allows specificati
       public:
         Rule( QgsAbstract3DSymbol *symbol /Transfer/, const QString &filterExp = QString(), const QString &description = QString(), bool elseRule = false );
 %Docstring
-takes ownership of symbol, symbol may be None
+takes ownership of symbol, symbol may be ``None``
 %End
         ~Rule();
 
@@ -89,7 +89,7 @@ takes ownership of symbol, symbol may be None
 
         QgsAbstract3DSymbol *symbol() const;
 %Docstring
-Returns the labeling settings. May return None.
+Returns the labeling settings. May return ``None``.
 %End
 
         QString filterExpression() const;
@@ -127,7 +127,7 @@ Unique rule identifier (for identification of rule within labeling, used as prov
 
         void setSymbol( QgsAbstract3DSymbol *symbol /Transfer/ );
 %Docstring
-Sets new symbol (or None). Deletes old symbol if any.
+Sets new symbol (or ``None``). Deletes old symbol if any.
 %End
 
         void setFilterExpression( const QString &filterExp );

python/analysis/auto_generated/raster/qgsalignraster.sip.in

@@ -137,11 +137,11 @@ Method to be overridden for progress reporting.
 
     void setProgressHandler( ProgressHandler *progressHandler );
 %Docstring
-Assign a progress handler instance. Does not take ownership. None can be passed.
+Assign a progress handler instance. Does not take ownership. ``None`` can be passed.
 %End
     ProgressHandler *progressHandler() const;
 %Docstring
-Gets associated progress handler. May be None (default)
+Gets associated progress handler. May be ``None`` (default)
 %End
 
     void setRasters( const List &list );

python/analysis/auto_generated/vector/geometry_checker/qgsfeaturepool.sip.in

@@ -60,7 +60,7 @@ Implementations will remove the feature from the layer or from the data provider
     QgsVectorLayer *layer() const;
 %Docstring
 Gets a pointer to the underlying layer.
-May return a ``None`` if the layer has been deleted.
+May return a ````None```` if the layer has been deleted.
 This must only be called from the main thread.
 %End
 

python/core/auto_generated/3d/qgs3drendererregistry.sip.in

@@ -33,7 +33,7 @@ Returns unique identifier of the 3D renderer class
 
     virtual QgsAbstract3DRenderer *createRenderer( QDomElement &elem, const QgsReadWriteContext &context ) = 0 /Factory/;
 %Docstring
-Returns new instance of the renderer given the DOM element. Returns None on error.
+Returns new instance of the renderer given the DOM element. Returns ``None`` on error.
 Pure virtual function: must be implemented in derived classes.
 %End
 

python/core/auto_generated/effects/qgspainteffectregistry.sip.in

@@ -68,7 +68,7 @@ Create a paint effect of this class given an encoded map of properties.
 
     virtual QgsPaintEffectWidget *createWidget() /Factory/;
 %Docstring
-Create configuration widget for paint effect of this class. Can return None
+Create configuration widget for paint effect of this class. Can return ``None``
 if there's no GUI for the paint effect class.
 
 :return: configuration widget
@@ -107,7 +107,7 @@ Returns the metadata for a specific effect.
 
 :param name: unique string name for paint effect class
 
-:return: paint effect metadata if found, otherwise None
+:return: paint effect metadata if found, otherwise ``None``
 %End
 
     bool addEffectType( QgsPaintEffectAbstractMetadata *metadata /Transfer/ );
@@ -126,7 +126,7 @@ Creates a new paint effect given the effect name and properties map.
 :param name: unique name representing paint effect class
 :param properties: encoded string map of effect properties
 
-:return: new paint effect of specified class, or None if matching
+:return: new paint effect of specified class, or ``None`` if matching
          paint effect could not be created
 %End
 
@@ -137,7 +137,7 @@ properties.
 
 :param element: encoded DOM element of effect properties
 
-:return: new paint effect, or None if matching
+:return: new paint effect, or ``None`` if matching
          paint effect could not be created
 %End
 

python/core/auto_generated/expression/qgsexpression.sip.in

@@ -294,14 +294,14 @@ Returns calculator used for distance and area calculations
 %Docstring
 Sets the geometry calculator used for distance and area calculations in expressions.
 (used by $length, $area and $perimeter functions only).
-If the geometry calculator is set to None (default), prepare() will read variables
+If the geometry calculator is set to ``None`` (default), prepare() will read variables
 from the expression context ("project_ellipsoid", "_project_transform_context" and
 "_layer_crs") to build a geometry calculator.
 If these variables does not exist and if setGeomCalculator() is not called,
 all distance and area calculations are performed using simple
 Cartesian methods (ie no ellipsoidal calculations).
 
-:param calc: geometry calculator. Ownership is not transferred. Set to a None to force
+:param calc: geometry calculator. Ownership is not transferred. Set to ``None`` to force
              Cartesian calculations.
 
 .. seealso:: :py:func:`geomCalculator`

python/core/auto_generated/expression/qgsexpressioncontextutils.sip.in

@@ -245,7 +245,7 @@ with the variables specified.
 Creates a new scope which contains variables and functions relating to a :py:class:`QgsLayoutAtlas`.
 For instance, current page name and number.
 
-:param atlas: source atlas. If None, a set of default atlas variables will be added to the scope.
+:param atlas: source atlas. If ``None``, a set of default atlas variables will be added to the scope.
 %End
 
     static QgsExpressionContextScope *layoutItemScope( const QgsLayoutItem *item ) /Factory/;

python/core/auto_generated/geometry/qgsabstractgeometry.sip.in

@@ -465,7 +465,7 @@ E.g. :py:class:`QgsLineString` -> :py:class:`QgsCompoundCurve`, :py:class:`QgsPo
 Makes a new geometry with all the points or vertices snapped to the closest point of the grid.
 Ownership is transferred to the caller.
 
-If the gridified geometry could not be calculated a None will be returned.
+If the gridified geometry could not be calculated ``None`` will be returned.
 It may generate an invalid geometry (in some corner cases).
 It can also be thought as rounding the edges and it may be useful for removing errors.
 Example:

python/core/auto_generated/geometry/qgscurve.sip.in

@@ -203,7 +203,7 @@ Returns an interpolated point on the curve at the specified ``distance``.
 If z or m values are present, the output z and m will be interpolated using
 the existing vertices' z or m values.
 
-If distance is negative, or is greater than the length of the curve, a None
+If distance is negative, or is greater than the length of the curve, ``None``
 will be returned.
 
 .. versionadded:: 3.4

python/core/auto_generated/geometry/qgsgeometry.sip.in

@@ -1448,7 +1448,7 @@ Try to convert the geometry to the requested type
 :param destType: the geometry type to be converted to
 :param destMultipart: determines if the output geometry will be multipart or not
 
-:return: the converted geometry or None if the conversion fails.
+:return: the converted geometry or ``None`` if the conversion fails.
 
 .. versionadded:: 2.2
 %End

python/core/auto_generated/geometry/qgsgeometryengine.sip.in

@@ -104,15 +104,15 @@ Calculate the symmetric difference of this and ``geom``.
     virtual QgsPoint *centroid( QString *errorMsg = 0 ) const = 0 /Factory/;
 %Docstring
 Calculates the centroid of this.
-May return a `None`.
+May return a ```None```.
 
 .. versionadded:: 3.0
 %End
 
     virtual QgsPoint *pointOnSurface( QString *errorMsg = 0 ) const = 0 /Factory/;
 %Docstring
 Calculate a point that is guaranteed to be on the surface of this.
-May return a `None`.
+May return a ```None```.
 
 .. versionadded:: 3.0
 %End

python/core/auto_generated/layertree/qgslayertreegroup.sip.in

@@ -136,13 +136,13 @@ Find all group layer nodes
 
     static QgsLayerTreeGroup *readXml( QDomElement &element, const QgsReadWriteContext &context ) /Factory/;
 %Docstring
-Read group (tree) from XML element <layer-tree-group> and return the newly created group (or None on error).
+Read group (tree) from XML element <layer-tree-group> and return the newly created group (or ``None`` on error).
 Does not resolve textual references to layers. Call resolveReferences() afterwards to do it.
 %End
 
     static QgsLayerTreeGroup *readXml( QDomElement &element, const QgsProject *project, const QgsReadWriteContext &context ) /Factory/;
 %Docstring
-Read group (tree) from XML element <layer-tree-group> and return the newly created group (or None on error).
+Read group (tree) from XML element <layer-tree-group> and return the newly created group (or ``None`` on error).
 Also resolves textual references to layers from the project (calls resolveReferences() internally).
 
 .. versionadded:: 3.0

python/core/auto_generated/layertree/qgslayertreelayer.sip.in

@@ -51,9 +51,9 @@ Returns the map layer associated with this node.
 
 .. warning::
 
-   This can be (and often is!) a None, e.g. in the case of a layer node representing a layer
+   This can be (and often is!) ``None``, e.g. in the case of a layer node representing a layer
    which has not yet been fully loaded into a project, or a layer node representing a layer
-   with an invalid data source. The returned pointer must ALWAYS be checked to avoid dereferencing a None.
+   with an invalid data source. The returned pointer must ALWAYS be checked to avoid dereferencing ``None``.
 
 .. seealso:: :py:func:`layerId`
 %End

python/core/auto_generated/layertree/qgslayertreemodel.sip.in

@@ -41,7 +41,7 @@ whether to allow changes to the layer tree.
 
     explicit QgsLayerTreeModel( QgsLayerTree *rootNode, QObject *parent /TransferThis/ = 0 );
 %Docstring
-Construct a new tree model with given layer tree (root node must not be None).
+Construct a new tree model with given layer tree (root node must not be ``None``).
 The root node is not transferred by the model.
 %End
 
@@ -112,7 +112,7 @@ Check whether a flag is enabled
     QgsLayerTreeNode *index2node( const QModelIndex &index ) const;
 %Docstring
 Returns layer tree node for given index. Returns root node for invalid index.
-Returns None if index does not refer to a layer tree node (e.g. it is a legend node)
+Returns ``None`` if index does not refer to a layer tree node (e.g. it is a legend node)
 %End
     QModelIndex node2index( QgsLayerTreeNode *node ) const;
 %Docstring
@@ -128,7 +128,7 @@ If ``skipInternal`` is ``True``, a node is included in the output list only if n
 
     static QgsLayerTreeModelLegendNode *index2legendNode( const QModelIndex &index );
 %Docstring
-Returns legend node for given index. Returns None for invalid index
+Returns legend node for given index. Returns ``None`` for invalid index
 
 .. versionadded:: 2.6
 %End
@@ -186,7 +186,7 @@ and rule key.
 
     QgsLayerTree *rootGroup() const;
 %Docstring
-Returns pointer to the root node of the layer tree. Always a non None value.
+Returns pointer to the root node of the layer tree. Always a non ``None`` value.
 %End
 
     void setRootGroup( QgsLayerTree *newRootGroup );
@@ -254,7 +254,7 @@ A scale <= 0 indicates that no scale filtering is being performed.
     void setLegendFilterByMap( const QgsMapSettings *settings );
 %Docstring
 Force only display of legend nodes which are valid for given map settings.
-Setting None or invalid map settings will disable the functionality.
+Setting ``None`` or invalid map settings will disable the functionality.
 Ownership of map settings pointer does not change, a copy is made.
 
 .. versionadded:: 2.6
@@ -264,7 +264,7 @@ Ownership of map settings pointer does not change, a copy is made.
 %Docstring
 Filter display of legend nodes for given map settings
 
-:param settings: Map settings. Setting a None or invalid settings will disable any filter. Ownership is not changed, a copy is made
+:param settings: Map settings. Setting ``None`` or invalid settings will disable any filter. Ownership is not changed, a copy is made
 :param useExtent: Whether to use the extent of the map settings as a first spatial filter on legend nodes
 :param polygon: If not empty, this polygon will be used instead of the map extent to filter legend nodes
 :param useExpressions: Whether to use legend node filter expressions
@@ -274,7 +274,7 @@ Filter display of legend nodes for given map settings
 
     const QgsMapSettings *legendFilterMapSettings() const;
 %Docstring
-Returns the current map settings used for the current legend filter (or None if none is enabled)
+Returns the current map settings used for the current legend filter (or ``None`` if none is enabled)
 
 .. versionadded:: 2.14
 %End
@@ -289,7 +289,7 @@ so that legend nodes that use map units can be scaled currectly
 
     void legendMapViewData( double *mapUnitsPerPixel /Out/, int *dpi /Out/, double *scale  /Out/ ) const;
 %Docstring
-Gets hints about map view - to be used in legend nodes. Arguments that are not None will receive values.
+Gets hints about map view - to be used in legend nodes. Arguments that are not ``None`` will receive values.
 If there are no valid map view data (from previous call to setLegendMapViewData()), returned values are zeros.
 
 .. versionadded:: 2.6

python/core/auto_generated/layertree/qgslayertreemodellegendnode.sip.in

@@ -93,15 +93,15 @@ Default implementation does nothing. *
 Entry point called from QgsLegendRenderer to do the rendering.
 Default implementation calls drawSymbol() and drawSymbolText() methods.
 
-If ctx is None, this is just first stage when preparing layout - without actual rendering.
+If ctx is ``None``, this is just first stage when preparing layout - without actual rendering.
 %End
 
     virtual QSizeF drawSymbol( const QgsLegendSettings &settings, ItemContext *ctx, double itemHeight ) const;
 %Docstring
 Draws symbol on the left side of the item
 
 :param settings: Legend layout configuration
-:param ctx: Context for rendering - may be None if only doing layout without actual rendering
+:param ctx: Context for rendering - may be ``None`` if only doing layout without actual rendering
 :param itemHeight: Minimal height of the legend item - used for correct positioning when rendering
 
 :return: Real size of the symbol (may be bigger than "normal" symbol size from settings)
@@ -112,7 +112,7 @@ Draws symbol on the left side of the item
 Draws label on the right side of the item
 
 :param settings: Legend layout configuration
-:param ctx: Context for rendering - may be nullptrnullptr if only doing layout without actual rendering
+:param ctx: Context for rendering - may be ``None`` if only doing layout without actual rendering
 :param symbolSize: Real size of the associated symbol - used for correct positioning when rendering
 
 :return: Size of the label (may span multiple lines)

python/core/auto_generated/layertree/qgslayertreenode.sip.in

@@ -89,7 +89,7 @@ Find out about type of the node. It is usually shorter to use convenience functi
 %End
     QgsLayerTreeNode *parent();
 %Docstring
-Gets pointer to the parent. If parent is None, the node is a root node
+Gets pointer to the parent. If parent is ``None``, the node is a root node
 %End
     QList<QgsLayerTreeNode *> children();
 %Docstring

python/core/auto_generated/layout/qgsabstractreportsection.sip.in

@@ -143,7 +143,7 @@ section.
 
     virtual QgsLayout *nextBody( bool &ok /Out/ );
 %Docstring
-Returns the next body layout to export, or a None if
+Returns the next body layout to export, or ``None`` if
 no body layout is required this iteration.
 
 ``ok`` will be set to ``False`` if no bodies remain for this section.

python/core/auto_generated/layout/qgslayout.sip.in

@@ -78,7 +78,7 @@ Calling this method removes all items and pages from the layout.
     QgsProject *project() const;
 %Docstring
 The project associated with the layout. Used to get access to layers, map themes,
-relations and various other bits. It is never None.
+relations and various other bits. It is never ``None``.
 %End
 
     QgsLayoutModel *itemsModel();
@@ -177,7 +177,7 @@ which deferred z-order updates.
 
     QgsLayoutItem *itemByUuid( const QString &uuid, bool includeTemplateUuids = false ) const;
 %Docstring
-Returns the layout item with matching ``uuid`` unique identifier, or a None
+Returns the layout item with matching ``uuid`` unique identifier, or ``None``
 if a matching item could not be found.
 
 If ``includeTemplateUuids`` is ``True``, then item's template UUID
@@ -196,7 +196,7 @@ Note that template UUIDs are only available while a layout is being restored fro
 
     QgsLayoutItem *itemByTemplateUuid( const QString &uuid ) const;
 %Docstring
-Returns the layout item with matching template ``uuid`` unique identifier, or a None
+Returns the layout item with matching template ``uuid`` unique identifier, or ``None``
 if a matching item could not be found. Unlike itemByUuid(), this method ONLY checks
 template UUIDs for a match.
 
@@ -224,7 +224,7 @@ item found.
 
     QgsLayoutMultiFrame *multiFrameByUuid( const QString &uuid, bool includeTemplateUuids = false ) const;
 %Docstring
-Returns the layout multiframe with matching ``uuid`` unique identifier, or a None
+Returns the layout multiframe with matching ``uuid`` unique identifier, or ``None``
 if a matching multiframe could not be found.
 
 If ``includeTemplateUuids`` is ``True``, then the multiframe's :py:func:`QgsLayoutMultiFrame.templateUuid()`
@@ -438,7 +438,7 @@ Returns list of keys stored in custom properties for the layout.
 %Docstring
 Returns the map item which will be used to generate corresponding world files when the
 layout is exported. If no map was explicitly set via setReferenceMap(), the largest
-map in the layout will be returned (or None if there are no maps in the layout).
+map in the layout will be returned (or ``None`` if there are no maps in the layout).
 
 .. seealso:: :py:func:`setReferenceMap`
 %End
@@ -587,7 +587,7 @@ and it's associated objects.
     QgsLayoutItemGroup *groupItems( const QList<QgsLayoutItem *> &items );
 %Docstring
 Creates a new group from a list of layout ``items`` and adds the group to the layout.
-If grouping was not possible, a None will be returned.
+If grouping was not possible, ``None`` will be returned.
 
 .. seealso:: :py:func:`ungroupItems`
 %End
@@ -637,7 +637,7 @@ Emitted whenever the expression variables stored in the layout have been changed
     void selectedItemChanged( QgsLayoutItem *selected );
 %Docstring
 Emitted whenever the selected item changes.
-If None, no item is selected.
+If ``None``, no item is selected.
 %End
 
     void refreshed();

python/core/auto_generated/layout/qgslayoutexporter.sip.in

@@ -326,7 +326,7 @@ an export.
 %Docstring
 Georeferences a ``file`` (image of PDF) exported from the layout.
 
-The ``referenceMap`` argument specifies a map item to use for georeferencing. If left as None, the
+The ``referenceMap`` argument specifies a map item to use for georeferencing. If left as ``None``, the
 default layout QgsLayout.referenceMap() will be used.
 
 The ``exportRegion`` argument can be set to a valid rectangle to indicate that only part of the layout was