Table of Contents
Glib::RefPtr
is a smartpointer. Specifically, it is a
reference-counting smartpointer. You might be familiar with
std::unique_ptr<>
and std::shared_ptr<>
, which are also smartpointers.
In gtkmm-4.0 Glib::RefPtr<>
is an alias for
std::shared_ptr<>
,
which is reference-counting. Glib::RefPtr<>
was introduced
long before there was a reference-counting smartpointer in the C++ Standard Library.
If you make your own Glib::ObjectBase
-derived classes with
create()
methods that return a Glib::RefPtr
,
you must use Glib::make_refptr_for_instance()
in your
create()
methods. This function creates a std::shared_ptr
with a special deleter, which handles the reference-count for the wrapped C object.
A smartpointer acts much like a normal pointer. Here are a few examples.
You can copy RefPtr
s, just like normal pointers. But
unlike normal pointers, you don't need to worry about deleting the underlying
instance.
auto refPixbuf = Gdk::Pixbuf::create_from_file(filename); auto refPixbuf2 = refPixbuf;
Of course this means that you can store RefPtr
s in
standard containers, such as std::vector
or
std::list
.
std::list<Glib::RefPtr<Gdk::Pixbuf>> listPixbufs; auto refPixbuf = Gdk::Pixbuf::create_from_file(filename); listPixbufs.push_back(refPixbuf);