gtkmm: Gtk::ListStore Class Reference

Thist is a list model for use with a Gtk::TreeView widget. More...

#include <gtkmm/liststore.h>

Inheritance diagram for Gtk::ListStore:

Public Member Functions

 ListStore (ListStore&& src) noexcept
 
ListStoreoperator= (ListStore&& src) noexcept
 
 ~ListStore () noexcept override
 
GtkListStore* gobj ()
 Provides access to the underlying C GObject. More...

 
const GtkListStore* gobj () const
 Provides access to the underlying C GObject. More...

 
GtkListStore* gobj_copy ()
 Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs. More...

 
void set_column_types (const TreeModelColumnRecord& columns)
 
iterator erase (const iterator& iter)
 Removes the given row from the list store. More...

 
iterator insert (const iterator& iter)
 Creates a new row before the position. More...

 
iterator insert_after (const iterator& iter)
 Creates a new row after the position. More...

 
iterator prepend ()
 Creates a new row at the start. More...

 
iterator append ()
 Creates a new row at the end. More...

 
void iter_swap (const iterator& a, const iterator& b)
 Swaps a and b in store. More...

 
void move (const iterator& source, const iterator& destination)
 Moves source to the position at destination. More...

 
void reorder (const std::vector< int >& new_order)
 Reorders the list store to follow the order indicated by new_order. More...

 
void clear ()
 Removes all rows from the list store. More...

 
bool iter_is_valid (const const_iterator& iter) const
 

This function is slow.

More...

 
- Public Member Functions inherited from Glib::Object
 Object (const Object &)=delete
 
Objectoperator= (const Object &)=delete
 
 Object (Object &&src) noexcept
 
Objectoperator= (Object &&src) noexcept
 
void * get_data (const QueryQuark &key)
 
void set_data (const Quark &key, void *data)
 
void set_data (const Quark &key, void *data, DestroyNotify notify)
 
void remove_data (const QueryQuark &quark)
 
void * steal_data (const QueryQuark &quark)
 
Glib::RefPtr< Glib::Objectwrap (GObject *object, bool take_copy=false)
 
- Public Member Functions inherited from Glib::ObjectBase
 ObjectBase (const ObjectBase &)=delete
 
ObjectBaseoperator= (const ObjectBase &)=delete
 
void set_property_value (const Glib::ustring &property_name, const Glib::ValueBase &value)
 
void get_property_value (const Glib::ustring &property_name, Glib::ValueBase &value) const
 
void set_property (const Glib::ustring &property_name, const PropertyType &value)
 
void get_property (const Glib::ustring &property_name, PropertyType &value) const
 
PropertyType get_property (const Glib::ustring &property_name) const
 
sigc::connection connect_property_changed (const Glib::ustring &property_name, const sigc::slot< void()> &slot)
 
sigc::connection connect_property_changed (const Glib::ustring &property_name, sigc::slot< void()> &&slot)
 
void freeze_notify ()
 
void thaw_notify ()
 
virtual void reference () const
 
virtual void unreference () const
 
GObject * gobj ()
 
const GObject * gobj () const
 
GObject * gobj_copy () const
 
- Public Member Functions inherited from sigc::trackable
 trackable () noexcept
 
 trackable (const trackable &src) noexcept
 
 trackable (trackable &&src) noexcept
 
 ~trackable ()
 
void add_destroy_notify_callback (notifiable *data, func_destroy_notify func) const
 
void notify_callbacks ()
 
trackableoperator= (const trackable &src)
 
trackableoperator= (trackable &&src) noexcept
 
void remove_destroy_notify_callback (notifiable *data) const
 
- Public Member Functions inherited from Gtk::TreeModel
 TreeModel (TreeModel&& src) noexcept
 
TreeModeloperator= (TreeModel&& src) noexcept
 
 ~TreeModel () noexcept override
 
GtkTreeModel* gobj ()
 Provides access to the underlying C GObject. More...

 
const GtkTreeModel* gobj () const
 Provides access to the underlying C GObject. More...

 
iterator get_iter (const Path& path)
 Returns a valid iterator pointing to path. More...

 
const_iterator get_iter (const Path& path) const
 Returns a valid iterator pointing to path. More...

 
iterator get_iter (const Glib::ustring& path_string)
 Returns a valid iterator pointing to path_string. More...

 
const_iterator get_iter (const Glib::ustring& path_string) const
 Returns a valid iterator pointing to path_string. More...

 
Children children ()
 This returns an STL-like container API, for iterating over the rows. More...

 
const ConstChildren children () const
 This returns an STL-like container API, for iterating over the rows. More...

 
void foreach_iter (const SlotForeachIter& slot)
 Calls a callback of type SlotForeachIter on each node in the model in a depth-first fashion. More...

 
void foreach_path (const SlotForeachPath& slot)
 Calls a callback of type SlotForeachPath on each node in the model in a depth-first fashion. More...

 
void foreach (const SlotForeachPathAndIter& slot)
 Calls a callback of type SlotForeachPathAndIter on each node in the model in a depth-first fashion. More...

 
Flags get_flags () const
 Returns a set of flags supported by this interface. More...

 
int get_n_columns () const
 Returns the number of columns supported by tree_model. More...

 
GType get_column_type (int index) const
 Returns the type of the column. More...

 
TreeModel::Path get_path (const const_iterator& iter) const
 Returns a Gtk::TreePath referenced by iter. More...

 
void row_changed (const Path& path, const const_iterator& iter)
 Emits the Gtk::TreeModel::signal_row_changed() signal on tree_model. More...

 
void row_inserted (const Path& path, const const_iterator& iter)
 Emits the Gtk::TreeModel::signal_row_inserted() signal on tree_model. More...

 
void row_has_child_toggled (const Path& path, const const_iterator& iter)
 Emits the Gtk::TreeModel::signal_row_has_child_toggled() signal on tree_model. More...

 
void row_deleted (const Path& path)
 Emits the Gtk::TreeModel::signal_row_deleted() signal on tree_model. More...

 
void rows_reordered (const Path& path, const const_iterator& iter, const std::vector< int >& new_order)
 Emits the "rows_reordered" signal on the tree model. More...

 
void rows_reordered (const Path& path, const std::vector< int >& new_order)
 Emits the "rows_reordered" signal on the tree model. More...

 
void rows_reordered (const Path& path, const const_iterator& iter, int* new_order)
 Emits the Gtk::TreeModel::signal_rows_reordered() signal on tree_model. More...

 
Glib::ustring get_string (const const_iterator& iter) const
 Generates a string representation of the iter. More...

 
Glib::SignalProxy< void(const TreeModel::Path&, const TreeModel::iterator&)> signal_row_changed ()
 
Glib::SignalProxy< void(const TreeModel::Path&, const TreeModel::iterator&)> signal_row_inserted ()
 
Glib::SignalProxy< void(const TreeModel::Path&, const TreeModel::iterator&)> signal_row_has_child_toggled ()
 
Glib::SignalProxy< void(const TreeModel::Path&)> signal_row_deleted ()
 
Glib::SignalProxy< void(const TreeModel::Path&, const TreeModel::iterator&, int*)> signal_rows_reordered ()
 
- Public Member Functions inherited from Glib::Interface
 Interface ()
 
 Interface (Interface &&src) noexcept
 
Interfaceoperator= (Interface &&src) noexcept
 
 Interface (const Glib::Interface_Class &interface_class)
 
 Interface (GObject *castitem)
 
 ~Interface () noexcept override
 
 Interface (const Interface &)=delete
 
Interfaceoperator= (const Interface &)=delete
 
GObject * gobj ()
 
const GObject * gobj () const
 
- Public Member Functions inherited from Gtk::TreeSortable
 TreeSortable (TreeSortable&& src) noexcept
 
TreeSortableoperator= (TreeSortable&& src) noexcept
 
 ~TreeSortable () noexcept override
 
GtkTreeSortable* gobj ()
 Provides access to the underlying C GObject. More...

 
const GtkTreeSortable* gobj () const
 Provides access to the underlying C GObject. More...

 
bool get_sort_column_id (int& sort_column_id, SortType& order) const
 Fills in sort_column_id and order with the current sort column and the order. More...

 
void set_sort_column (const TreeModelColumnBase& sort_column_id, SortType order)
 Sets the current sort column to be sort_column_id. More...

 
void set_sort_column (int sort_column_id, SortType order)
 Sets the current sort column to be sort_column_id. More...

 
void set_sort_func (const TreeModelColumnBase& sort_column, const SlotCompare& slot)
 Sets the comparison function used when sorting a certain column. More...

 
void set_sort_func (int sort_column_id, const SlotCompare& slot)
 Sets the comparison function used when sorting a certain column. More...

 
void set_default_sort_func (const SlotCompare& slot)
 Sets the default comparison function used when sorting. More...

 
void unset_default_sort_func ()
 Sets the default comparison function used when sorting. More...

 
bool has_default_sort_func () const
 Returns true if the model has a default sort function. More...

 
void sort_column_changed ()
 Emits a Gtk::TreeSortable::signal_sort_column_changed() signal on sortable. More...

 
Glib::SignalProxy< void()> signal_sort_column_changed ()
 
- Public Member Functions inherited from Gtk::TreeDragSource
 TreeDragSource (TreeDragSource&& src) noexcept
 
TreeDragSourceoperator= (TreeDragSource&& src) noexcept
 
 ~TreeDragSource () noexcept override
 
GtkTreeDragSource* gobj ()
 Provides access to the underlying C GObject. More...

 
const GtkTreeDragSource* gobj () const
 Provides access to the underlying C GObject. More...

 
bool row_draggable (const TreeModel::Path& path) const
 Asks the Gtk::TreeDragSource whether a particular row can be used as the source of a DND operation. More...

 
Glib::RefPtr< Gdk::ContentProviderdrag_data_get (const TreeModel::Path& path) const
 Asks the Gtk::TreeDragSource to return a Gdk::ContentProvider representing the row at path. More...

 
bool drag_data_delete (const TreeModel::Path& path)
 Asks the Gtk::TreeDragSource to delete the row at path, because it was moved somewhere else via drag-and-drop. More...

 
- Public Member Functions inherited from Gtk::TreeDragDest
 TreeDragDest (TreeDragDest&& src) noexcept
 
TreeDragDestoperator= (TreeDragDest&& src) noexcept
 
 ~TreeDragDest () noexcept override
 
GtkTreeDragDest* gobj ()
 Provides access to the underlying C GObject. More...

 
const GtkTreeDragDest* gobj () const
 Provides access to the underlying C GObject. More...

 
bool drag_data_received (const TreeModel::Path& dest, const Glib::ValueBase& value)
 Asks the Gtk::TreeDragDest to insert a row before the path dest, deriving the contents of the row from value. More...

 
bool row_drop_possible (const TreeModel::Path& dest_path, const Glib::ValueBase& value) const
 Determines whether a drop is possible before the given dest_path, at the same depth as dest_path. More...

 
- Public Member Functions inherited from Gtk::Buildable
 Buildable (Buildable&& src) noexcept
 
Buildableoperator= (Buildable&& src) noexcept
 
 ~Buildable () noexcept override
 
GtkBuildable* gobj ()
 Provides access to the underlying C GObject. More...

 
const GtkBuildable* gobj () const
 Provides access to the underlying C GObject. More...

 
Glib::ustring get_buildable_id () const
 Gets the ID of the buildable object. More...

 

Static Public Member Functions

static GType get_type ()
 Get the GType for this class, for use with the underlying GObject type system. More...

 
static Glib::RefPtr< ListStorecreate (const TreeModelColumnRecord& columns)
 Instantiate a new ListStore. More...

 
- Static Public Member Functions inherited from Gtk::TreeModel
static void add_interface (GType gtype_implementer)
 
static GType get_type ()
 Get the GType for this class, for use with the underlying GObject type system. More...

 
- Static Public Member Functions inherited from Gtk::TreeSortable
static void add_interface (GType gtype_implementer)
 
static GType get_type ()
 Get the GType for this class, for use with the underlying GObject type system. More...

 
- Static Public Member Functions inherited from Gtk::TreeDragSource
static void add_interface (GType gtype_implementer)
 
static GType get_type ()
 Get the GType for this class, for use with the underlying GObject type system. More...

 
- Static Public Member Functions inherited from Gtk::TreeDragDest
static void add_interface (GType gtype_implementer)
 
static GType get_type ()
 Get the GType for this class, for use with the underlying GObject type system. More...

 
- Static Public Member Functions inherited from Gtk::Buildable
static void add_interface (GType gtype_implementer)
 
static GType get_type ()
 Get the GType for this class, for use with the underlying GObject type system. More...

 

Protected Member Functions

 ListStore ()
 When using this constructor, you must use set_column_types() immediately afterwards. More...

 
 ListStore (const TreeModelColumnRecord& columns)
 
void set_value_impl (const iterator& row, int column, const Glib::ValueBase& value) override
 Override and implement this in a derived TreeModel class, so that Row::operator() and Row::set_value() work. More...

 
- Protected Member Functions inherited from Glib::Object
 Object ()
 
 Object (const Glib::ConstructParams &construct_params)
 
 Object (GObject *castitem)
 
 ~Object () noexcept override
 
- Protected Member Functions inherited from Glib::ObjectBase
 ObjectBase ()
 
 ObjectBase (const char *custom_type_name)
 
 ObjectBase (const std::type_info &custom_type_info)
 
 ObjectBase (ObjectBase &&src) noexcept
 
ObjectBaseoperator= (ObjectBase &&src) noexcept
 
virtual ~ObjectBase () noexcept=0
 
void initialize (GObject *castitem)
 
void initialize_move (GObject *castitem, Glib::ObjectBase *previous_wrapper)
 
- Protected Member Functions inherited from Gtk::TreeModel
 TreeModel ()
 You should derive from this class to use it. More...

 
virtual Flags get_flags_vfunc () const
 
virtual int get_n_columns_vfunc () const
 
virtual GType get_column_type_vfunc (int index) const
 
virtual bool iter_next_vfunc (const iterator& iter, iterator& iter_next) const
 Override and implement this in a derived TreeModel class. More...

 
virtual bool get_iter_vfunc (const Path& path, iterator& iter) const
 Override and implement this in a derived TreeModel class. More...

 
virtual bool iter_children_vfunc (const iterator& parent, iterator& iter) const
 Override and implement this in a derived TreeModel class. More...

 
virtual bool iter_parent_vfunc (const iterator& child, iterator& iter) const
 Override and implement this in a derived TreeModel class. More...

 
virtual bool iter_nth_child_vfunc (const iterator& parent, int n, iterator& iter) const
 Override and implement this in a derived TreeModel class. More...

 
virtual bool iter_nth_root_child_vfunc (int n, iterator& iter) const
 Override and implement this in a derived TreeModel class. More...

 
virtual bool iter_has_child_vfunc (const const_iterator& iter) const
 Override and implement this in a derived TreeModel class. More...

 
virtual int iter_n_children_vfunc (const const_iterator& iter) const
 Override and implement this in a derived TreeModel class. More...

 
virtual int iter_n_root_children_vfunc () const
 Override and implement this in a derived TreeModel class. More...

 
virtual void ref_node_vfunc (const iterator& iter) const
 Override and implement this in a derived TreeModel class. More...

 
virtual void unref_node_vfunc (const iterator& iter) const
 Override and implement this in a derived TreeModel class. More...

 
virtual TreeModel::Path get_path_vfunc (const const_iterator& iter) const
 Override and implement this in a derived TreeModel class. More...

 
virtual void get_value_vfunc (const const_iterator& iter, int column, Glib::ValueBase& value) const
 Override and implement this in a derived TreeModel class. More...

 
virtual void get_value_impl (const const_iterator& iter, int column, Glib::ValueBase& value) const
 
virtual void on_row_changed (const TreeModel::Path& path, const TreeModel::iterator& iter)
 This is a default handler for the signal signal_row_changed(). More...

 
virtual void on_row_inserted (const TreeModel::Path& path, const TreeModel::iterator& iter)
 This is a default handler for the signal signal_row_inserted(). More...

 
virtual void on_row_has_child_toggled (const TreeModel::Path& path, const TreeModel::iterator& iter)
 This is a default handler for the signal signal_row_has_child_toggled(). More...

 
virtual void on_row_deleted (const TreeModel::Path& path)
 This is a default handler for the signal signal_row_deleted(). More...

 
virtual void on_rows_reordered (const TreeModel::Path& path, const TreeModel::iterator& iter, int* new_order)
 This is a default handler for the signal signal_rows_reordered(). More...

 
- Protected Member Functions inherited from Gtk::TreeSortable
 TreeSortable ()
 You should derive from this class to use it. More...

 
virtual bool get_sort_column_id_vfunc (int* sort_column_id, SortType* order) const
 
virtual void set_sort_column_id_vfunc (int sort_column_id, SortType order)
 
virtual void set_sort_func_vfunc (int sort_column_id, GtkTreeIterCompareFunc func, void* data, GDestroyNotify destroy)
 
virtual void set_default_sort_func_vfunc (GtkTreeIterCompareFunc func, void* data, GDestroyNotify destroy)
 
virtual bool has_default_sort_func_vfunc () const
 
virtual void sort_column_changed_vfunc () const
 
virtual void on_sort_column_changed ()
 This is a default handler for the signal signal_sort_column_changed(). More...

 
- Protected Member Functions inherited from Gtk::TreeDragSource
 TreeDragSource ()
 You should derive from this class to use it. More...

 
virtual bool row_draggable_vfunc (const TreeModel::Path& path) const
 
virtual Glib::RefPtr< Gdk::ContentProviderdrag_data_get_vfunc (const TreeModel::Path& path) const
 
virtual bool drag_data_delete_vfunc (const TreeModel::Path& path)
 
- Protected Member Functions inherited from Gtk::TreeDragDest
 TreeDragDest ()
 You should derive from this class to use it. More...

 
virtual bool drag_data_received_vfunc (const TreeModel::Path& dest, const Glib::ValueBase& value)
 
virtual bool row_drop_possible_vfunc (const TreeModel::Path& dest, const Glib::ValueBase& value) const
 
- Protected Member Functions inherited from Gtk::Buildable
 Buildable ()
 You should derive from this class to use it. More...

 

Related Functions

(Note that these are not member functions.)

Glib::RefPtr< Gtk::ListStorewrap (GtkListStore* object, bool take_copy=false)
 A Glib::wrap() method for this object. More...

 

Additional Inherited Members

- Public Types inherited from Glib::Object
typedef void(*)(gpointer data DestroyNotify)
 
- Public Types inherited from sigc::trackable
typedef internal::func_destroy_notify func_destroy_notify
 
- Public Types inherited from sigc::notifiable
typedef internal::func_destroy_notify func_destroy_notify
 
- Public Types inherited from Gtk::TreeModel
enum  Flags {

  Flags::ITERS_PERSIST = 1 << 0,

  Flags::LIST_ONLY = 1 << 1

}
 These flags indicate various properties of a Gtk::TreeModel. More...

 
typedef TreeModelColumnRecord ColumnRecord
 
typedef TreeNodeChildren Children
 
typedef TreeNodeConstChildren ConstChildren
 
typedef Children::iterator iterator
 
typedef ConstChildren::const_iterator const_iterator
 
typedef TreeConstRow ConstRow
 
typedef TreeRow Row
 
typedef TreePath Path
 
typedef TreeRowReference RowReference
 
typedef sigc::slot< bool(const TreeModel::iterator&)> SlotForeachIter
 The type of callback slot used by foreach_iter(). More...

 
typedef sigc::slot< bool(const TreeModel::Path&)> SlotForeachPath
 The type of callback slot used by foreach_path(). More...

 
typedef sigc::slot< bool(const TreeModel::Path&, const TreeModel::iterator&)> SlotForeachPathAndIter
 The type of callback slot used by foreach(). More...

 
- Public Types inherited from Gtk::TreeSortable
enum  {

  DEFAULT_SORT_COLUMN_ID = -1,

  DEFAULT_UNSORTED_COLUMN_ID = -2

}
 
typedef sigc::slot< int(const Gtk::TreeModel::const_iterator&, const Gtk::TreeModel::const_iterator&)> SlotCompare
 This callback should return -1 if a compares before b, 0 if they compare equal, 1 if a compares after b. More...

 

Detailed Description

Thist is a list model for use with a Gtk::TreeView widget.

It implements the Gtk::TreeModel interface, and also implements the Gtk::TreeSortable interface so you can sort the list using the view. Finally, it also implements the tree drag and drop interfaces.

Constructor & Destructor Documentation

Gtk::ListStore::ListStore ( ListStore&&  src)
noexcept
Gtk::ListStore::~ListStore ( )
overridenoexcept
Gtk::ListStore::ListStore ( )
protected

When using this constructor, you must use set_column_types() immediately afterwards.

This can be useful when deriving from this class, with a fixed TreeModelColumnRecord that is a member of the class. There is no create() method that corresponds to this constructor, because this constructor should only be used by derived classes.

Gtk::ListStore::ListStore ( const TreeModelColumnRecord columns)
explicitprotected

Member Function Documentation

iterator Gtk::ListStore::append ( )

Creates a new row at the end.

The row will be empty - to fill in values, you need to dereference the returned iterator and use Row::operator[] or Row::set_value(). See also insert() and prepend().

Returns
An iterator to the new row.
void Gtk::ListStore::clear ( )

Removes all rows from the list store.

static Glib::RefPtr<ListStore> Gtk::ListStore::create ( const TreeModelColumnRecord columns)
static

Instantiate a new ListStore.

Parameters
columnsThe column types for this tree model.
Returns
The new ListStore.
iterator Gtk::ListStore::erase ( const iterator iter)

Removes the given row from the list store.

Parameters
iterThe iterator to the row to be removed.
Returns
An iterator to the next row, or end() if there is none.
static GType Gtk::ListStore::get_type ( )
static

Get the GType for this class, for use with the underlying GObject type system.

GtkListStore* Gtk::ListStore::gobj ( )
inline

Provides access to the underlying C GObject.

const GtkListStore* Gtk::ListStore::gobj ( ) const
inline

Provides access to the underlying C GObject.

GtkListStore* Gtk::ListStore::gobj_copy ( )

Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs.

iterator Gtk::ListStore::insert ( const iterator iter)

Creates a new row before the position.

If iter is end() then a new row will be appended to the list. The row will be empty - to fill in values, you need to dereference the returned iterator and use Row::operator[] or Row::set_value(). See also prepend() and append().

Parameters
iterAn iterator to the row before which the new row will be inserted.
Returns
An iterator to the new row.
iterator Gtk::ListStore::insert_after ( const iterator iter)

Creates a new row after the position.

If iter is end() then a new row will be prepended to the list. The row will be empty - to fill in values, you need to dereference the returned iterator and use Row::operator[] or Row::set_value(). See also insert(), prepend() and append().

Parameters
iterAn iterator to the row after which the new row will be inserted.
Returns
An iterator to the new row.
bool Gtk::ListStore::iter_is_valid ( const const_iterator iter) const

This function is slow.

Only use it for debugging and/or testing

purposes.

Checks if the given iter is a valid iter for this Gtk::ListStore.

Parameters
iterA Gtk::TreeIter.
Returns
true if the iter is valid, false if the iter is invalid.
void Gtk::ListStore::iter_swap ( const iterator a,
const iterator b 
)

Swaps a and b in store.

Note that this function only works with unsorted stores.

Parameters
aA Gtk::TreeIter.
bAnother Gtk::TreeIter.
void Gtk::ListStore::move ( const iterator source,
const iterator destination 
)

Moves source to the position at destination.

Note that this function only works with unsorted stores.

Parameters
sourceThe row that should be moved.
destinationThe position to move to.
ListStore& Gtk::ListStore::operator= ( ListStore&&  src)
noexcept
iterator Gtk::ListStore::prepend ( )

Creates a new row at the start.

The row will be empty - to fill in values, you need to dereference the returned iterator and use Row::operator[] or Row::set_value(). See also insert() and append().

Returns
An iterator to the new row.
void Gtk::ListStore::reorder ( const std::vector< int > &  new_order)

Reorders the list store to follow the order indicated by new_order.

Note that this function only works with unsorted stores.

void Gtk::ListStore::set_column_types ( const TreeModelColumnRecord columns)
void Gtk::ListStore::set_value_impl ( const iterator iter,
int  column,
const Glib::ValueBase value 
)
overrideprotectedvirtual

Override and implement this in a derived TreeModel class, so that Row::operator() and Row::set_value() work.

Your implementation of set_value_impl() should call row_changed() after changing the value.

Reimplemented from Gtk::TreeModel.

Friends And Related Function Documentation

Glib::RefPtr< Gtk::ListStore > wrap ( GtkListStore *  object,
bool  take_copy = false 
)
related

A Glib::wrap() method for this object.

Parameters
objectThe C instance.
take_copyFalse if the result should take ownership of the C instance. True if it should take a new copy or ref.
Returns
A C++ instance that wraps this C instance.