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authorMurray Cumming <murrayc@murrayc.com>2016-04-10 11:59:00 +0200
committerMurray Cumming <murrayc@murrayc.com>2017-04-07 11:03:48 +0200
commit62e5b60a7f9c353a5198354ec9ac12b312e326ee (patch)
tree6e88a353b5bcc19307aae1d6e49a3d4c9b1f882a /glib/glibmm/refptr.h
parent38cba7e9aaa18e735f7e2ca32b909e92b8d27091 (diff)
downloadglibmm-62e5b60a7f9c353a5198354ec9ac12b312e326ee.tar.gz
RefPtr: Make this an alias for shared_ptr<> instead.
Specifying a Deleter in make_refptr_for_instance(). And changing RefPtr::cast_dynamic<>() to std::dynamic_pointer_cast<>(). The glibmm_refptr test then becomes rather silly, and should maybe just be removed.
Diffstat (limited to 'glib/glibmm/refptr.h')
-rw-r--r--glib/glibmm/refptr.h464
1 files changed, 25 insertions, 439 deletions
diff --git a/glib/glibmm/refptr.h b/glib/glibmm/refptr.h
index bdcc9211..eee7f176 100644
--- a/glib/glibmm/refptr.h
+++ b/glib/glibmm/refptr.h
@@ -20,11 +20,22 @@
#include <glibmmconfig.h>
#include <glib.h>
-#include <utility>
+#include <memory>
namespace Glib
{
+class ObjectBase;
+
+template <class T_CppObject>
+void RefPtrDeleter(T_CppObject* object)
+{
+ if (!object)
+ return;
+
+ object->unreference();
+}
+
/** RefPtr<> is a reference-counting shared smartpointer.
*
* Some objects in gtkmm are obtained from a shared
@@ -49,452 +60,27 @@ namespace Glib
* book for further information.
*/
template <class T_CppObject>
-class RefPtr
-{
-private:
-#ifndef DOXYGEN_SHOULD_SKIP_THIS
- /** Helper class for disallowing use of Glib::RefPtr with certain classes.
- *
- * Disallow for instance in Gtk::Widget and its subclasses.
- * Glib::RefPtr<T>::is_allowed_type::value is false if
- * T:dont_allow_use_in_glib_refptr_ is a public type, else it's true.
- * Example:
- * @code
- * using dont_allow_use_in_glib_refptr_ = int;
- * @endcode
- */
- class is_allowed_type
- {
- private:
- struct big
- {
- int memory[64];
- };
-
- static big check(...);
-
- // If X::dont_allow_use_in_glib_refptr_ is not a type, this check() overload
- // is ignored because of the SFINAE rule (Substitution Failure Is Not An Error).
- template <typename X>
- static typename X::dont_allow_use_in_glib_refptr_ check(X* obj);
-
- public:
- static const bool value = sizeof(check(static_cast<T_CppObject*>(nullptr))) == sizeof(big);
- };
-
- static_assert(is_allowed_type::value, "Glib::RefPtr must not be used with this class.");
-#endif /* DOXYGEN_SHOULD_SKIP_THIS */
-
-public:
- /** Default constructor
- *
- * Afterwards it will be null and use of -> will cause a segmentation fault.
- */
- inline RefPtr() noexcept;
-
- /// Destructor - decrements reference count.
- inline ~RefPtr() noexcept;
-
- /// For use only by the \::create() methods.
- explicit inline RefPtr(T_CppObject* pCppObject) noexcept;
-
- /** Copy constructor
- *
- * This increments the shared reference count.
- */
- inline RefPtr(const RefPtr& src) noexcept;
-
- /** Move constructor
- */
- inline RefPtr(RefPtr&& src) noexcept;
-
- /** Move constructor (from different, but castable type).
- */
- template <class T_CastFrom>
- inline RefPtr(RefPtr<T_CastFrom>&& src) noexcept;
-
- /** Copy constructor (from different, but castable type).
- *
- * Increments the reference count.
- */
- template <class T_CastFrom>
- inline RefPtr(const RefPtr<T_CastFrom>& src) noexcept;
-
- /** Swap the contents of two RefPtr<>.
- * This method swaps the internal pointers to T_CppObject. This can be
- * done safely without involving a reference/unreference cycle and is
- * therefore highly efficient.
- */
- inline void swap(RefPtr& other) noexcept;
-
- /// Copy from another RefPtr:
- inline RefPtr& operator=(const RefPtr& src) noexcept;
-
- /// Move assignment operator:
- inline RefPtr& operator=(RefPtr&& src) noexcept;
-
- /// Move assignment operator (from different, but castable type):
- template <class T_CastFrom>
- inline RefPtr& operator=(RefPtr<T_CastFrom>&& src) noexcept;
-
- /** Copy from different, but castable type).
- *
- * Increments the reference count.
- */
- template <class T_CastFrom>
- inline RefPtr& operator=(const RefPtr<T_CastFrom>& src) noexcept;
-
- /// Tests whether the RefPtr<> point to the same underlying instance.
- inline bool operator==(const RefPtr& src) const noexcept;
-
- /// See operator==().
- inline bool operator!=(const RefPtr& src) const noexcept;
-
- /** Dereferencing.
- *
- * Use the methods of the underlying instance like so:
- * <code>refptr->memberfun()</code>.
- */
- inline T_CppObject* operator->() const noexcept;
-
- /** Test whether the RefPtr<> points to any underlying instance.
- *
- * Mimics usage of ordinary pointers:
- * @code
- * if (ptr)
- * do_something();
- * @endcode
- */
- inline explicit operator bool() const noexcept;
-
- /** Set underlying instance to nullptr, decrementing reference count of existing instance
- * appropriately.
- * @newin{2,16}
- */
- inline void reset() noexcept;
-
- /** Release the ownership of underlying instance.
- *
- * RefPtr's underlying instance is set to nullptr, therefore underlying object can't be accessed
- * through this RefPtr anymore.
- * @return an underlying instance.
- *
- * Most users should not use release(). It can spoil the automatic destruction
- * of the managed object. A legitimate use is if you immediately give RefPtr's
- * reference to another object.
- */
- inline T_CppObject* release() noexcept G_GNUC_WARN_UNUSED_RESULT;
-
- /** Dynamic cast to derived class.
- *
- * The RefPtr can't be cast with the usual notation so instead you can use
- * @code
- * ptr_derived = RefPtr<Derived>::cast_dynamic(ptr_base);
- * @endcode
- */
- template <class T_CastFrom>
- static inline RefPtr cast_dynamic(const RefPtr<T_CastFrom>& src) noexcept;
-
- /** Static cast to derived class.
- *
- * Like the dynamic cast; the notation is
- * @code
- * ptr_derived = RefPtr<Derived>::cast_static(ptr_base);
- * @endcode
- */
- template <class T_CastFrom>
- static inline RefPtr cast_static(const RefPtr<T_CastFrom>& src) noexcept;
-
- /** Cast to non-const.
- *
- * The RefPtr can't be cast with the usual notation so instead you can use
- * @code
- * ptr_unconst = RefPtr<UnConstType>::cast_const(ptr_const);
- * @endcode
- */
- template <class T_CastFrom>
- static inline RefPtr cast_const(const RefPtr<T_CastFrom>& src) noexcept;
-
- /** Compare based on the underlying instance address.
- *
- * This is needed in code that requires an ordering on
- * RefPtr<T_CppObject> instances, e.g. std::set<RefPtr<T_CppObject> >.
- *
- * Without these, comparing two RefPtr<T_CppObject> instances
- * is still syntactically possible, but the result is semantically
- * wrong, as p1 REL_OP p2 is interpreted as (bool)p1 REL_OP (bool)p2.
- */
- inline bool operator<(const RefPtr& src) const noexcept;
-
- /// See operator<().
- inline bool operator<=(const RefPtr& src) const noexcept;
-
- /// See operator<().
- inline bool operator>(const RefPtr& src) const noexcept;
-
- /// See operator<().
- inline bool operator>=(const RefPtr& src) const noexcept;
-
-private:
- T_CppObject* pCppObject_;
-};
-
-#ifndef DOXYGEN_SHOULD_SKIP_THIS
-
-// RefPtr<>::operator->() comes first here since it's used by other methods.
-// If it would come after them it wouldn't be inlined.
-
-template <class T_CppObject>
-inline T_CppObject* RefPtr<T_CppObject>::operator->() const noexcept
-{
- return pCppObject_;
-}
-
-template <class T_CppObject>
-inline RefPtr<T_CppObject>::RefPtr() noexcept : pCppObject_(nullptr)
-{
-}
-
-template <class T_CppObject>
-inline RefPtr<T_CppObject>::~RefPtr() noexcept
-{
- if (pCppObject_)
- pCppObject_->unreference(); // This could cause pCppObject to be deleted.
-}
-
-template <class T_CppObject>
-inline RefPtr<T_CppObject>::RefPtr(T_CppObject* pCppObject) noexcept : pCppObject_(pCppObject)
-{
-}
-
-template <class T_CppObject>
-inline RefPtr<T_CppObject>::RefPtr(const RefPtr& src) noexcept : pCppObject_(src.pCppObject_)
-{
- if (pCppObject_)
- pCppObject_->reference();
-}
-
-template <class T_CppObject>
-inline RefPtr<T_CppObject>::RefPtr(RefPtr&& src) noexcept : pCppObject_(src.pCppObject_)
-{
- src.pCppObject_ = nullptr;
-}
-
-template <class T_CppObject>
-template <class T_CastFrom>
-inline RefPtr<T_CppObject>::RefPtr(RefPtr<T_CastFrom>&& src) noexcept : pCppObject_(src.release())
-{
-}
-
-// The templated ctor allows copy construction from any object that's
-// castable. Thus, it does downcasts:
-// base_ref = derived_ref
-template <class T_CppObject>
-template <class T_CastFrom>
-inline RefPtr<T_CppObject>::RefPtr(const RefPtr<T_CastFrom>& src) noexcept :
- // A different RefPtr<> will not allow us access to pCppObject_. We need
- // to add a get_underlying() for this, but that would encourage incorrect
- // use, so we use the less well-known operator->() accessor:
- pCppObject_(src.operator->())
-{
- if (pCppObject_)
- pCppObject_->reference();
-}
-
-template <class T_CppObject>
-inline void
-RefPtr<T_CppObject>::swap(RefPtr& other) noexcept
-{
- T_CppObject* const temp = pCppObject_;
- pCppObject_ = other.pCppObject_;
- other.pCppObject_ = temp;
-}
-
-template <class T_CppObject>
-inline RefPtr<T_CppObject>&
-RefPtr<T_CppObject>::operator=(const RefPtr& src) noexcept
-{
- // In case you haven't seen the swap() technique to implement copy
- // assignment before, here's what it does:
- //
- // 1) Create a temporary RefPtr<> instance via the copy ctor, thereby
- // increasing the reference count of the source object.
- //
- // 2) Swap the internal object pointers of *this and the temporary
- // RefPtr<>. After this step, *this already contains the new pointer,
- // and the old pointer is now managed by temp.
- //
- // 3) The destructor of temp is executed, thereby unreferencing the
- // old object pointer.
- //
- // This technique is described in Herb Sutter's "Exceptional C++", and
- // has a number of advantages over conventional approaches:
- //
- // - Code reuse by calling the copy ctor.
- // - Strong exception safety for free.
- // - Self assignment is handled implicitely.
- // - Simplicity.
- // - It just works and is hard to get wrong; i.e. you can use it without
- // even thinking about it to implement copy assignment whereever the
- // object data is managed indirectly via a pointer, which is very common.
-
- RefPtr<T_CppObject> temp(src);
- this->swap(temp);
- return *this;
-}
-
-template <class T_CppObject>
-inline RefPtr<T_CppObject>&
-RefPtr<T_CppObject>::operator=(RefPtr&& src) noexcept
-{
- RefPtr<T_CppObject> temp(std::move(src));
- this->swap(temp);
- src.pCppObject_ = nullptr;
-
- return *this;
-}
-
-template <class T_CppObject>
-template <class T_CastFrom>
-inline RefPtr<T_CppObject>&
-RefPtr<T_CppObject>::operator=(RefPtr<T_CastFrom>&& src) noexcept
-{
- if (pCppObject_)
- pCppObject_->unreference();
- pCppObject_ = src.release();
-
- return *this;
-}
-
-template <class T_CppObject>
-template <class T_CastFrom>
-inline RefPtr<T_CppObject>&
-RefPtr<T_CppObject>::operator=(const RefPtr<T_CastFrom>& src) noexcept
-{
- RefPtr<T_CppObject> temp(src);
- this->swap(temp);
- return *this;
-}
-
-template <class T_CppObject>
-inline bool
-RefPtr<T_CppObject>::operator==(const RefPtr& src) const noexcept
-{
- return (pCppObject_ == src.pCppObject_);
-}
-
-template <class T_CppObject>
-inline bool
-RefPtr<T_CppObject>::operator!=(const RefPtr& src) const noexcept
-{
- return (pCppObject_ != src.pCppObject_);
-}
-
-template <class T_CppObject>
-inline RefPtr<T_CppObject>::operator bool() const noexcept
-{
- return (pCppObject_ != nullptr);
-}
-
-template <class T_CppObject>
-inline void
-RefPtr<T_CppObject>::reset() noexcept
-{
- RefPtr<T_CppObject> temp; // swap with an empty RefPtr<> to clear *this
- this->swap(temp);
-}
-
-template <class T_CppObject>
-inline T_CppObject*
-RefPtr<T_CppObject>::release() noexcept
-{
- T_CppObject* tmp = pCppObject_;
- pCppObject_ = nullptr;
- return tmp;
-}
-
-template <class T_CppObject>
-template <class T_CastFrom>
-inline RefPtr<T_CppObject>
-RefPtr<T_CppObject>::cast_dynamic(const RefPtr<T_CastFrom>& src) noexcept
-{
- T_CppObject* const pCppObject = dynamic_cast<T_CppObject*>(src.operator->());
-
- if (pCppObject)
- pCppObject->reference();
-
- return RefPtr<T_CppObject>(pCppObject);
-}
-
-template <class T_CppObject>
-template <class T_CastFrom>
-inline RefPtr<T_CppObject>
-RefPtr<T_CppObject>::cast_static(const RefPtr<T_CastFrom>& src) noexcept
-{
- T_CppObject* const pCppObject = static_cast<T_CppObject*>(src.operator->());
-
- if (pCppObject)
- pCppObject->reference();
-
- return RefPtr<T_CppObject>(pCppObject);
-}
-
-template <class T_CppObject>
-template <class T_CastFrom>
-inline RefPtr<T_CppObject>
-RefPtr<T_CppObject>::cast_const(const RefPtr<T_CastFrom>& src) noexcept
-{
- T_CppObject* const pCppObject = const_cast<T_CppObject*>(src.operator->());
-
- if (pCppObject)
- pCppObject->reference();
-
- return RefPtr<T_CppObject>(pCppObject);
-}
-
-template <class T_CppObject>
-inline bool
-RefPtr<T_CppObject>::operator<(const RefPtr& src) const noexcept
-{
- return (pCppObject_ < src.pCppObject_);
-}
-
-template <class T_CppObject>
-inline bool
-RefPtr<T_CppObject>::operator<=(const RefPtr& src) const noexcept
-{
- return (pCppObject_ <= src.pCppObject_);
-}
+using RefPtr = std::shared_ptr<T_CppObject>;
-template <class T_CppObject>
-inline bool
-RefPtr<T_CppObject>::operator>(const RefPtr& src) const noexcept
-{
- return (pCppObject_ > src.pCppObject_);
-}
-
-template <class T_CppObject>
-inline bool
-RefPtr<T_CppObject>::operator>=(const RefPtr& src) const noexcept
-{
- return (pCppObject_ >= src.pCppObject_);
-}
-
-#endif /* DOXYGEN_SHOULD_SKIP_THIS */
-
-/** @relates Glib::RefPtr */
-template <class T_CppObject>
-inline void
-swap(RefPtr<T_CppObject>& lhs, RefPtr<T_CppObject>& rhs) noexcept
+/** This would not be useful,
+ * because application code should not new these objects anyway.
+ * And it is not useful inside glibmm or gtkmm code because
+ * the constructors are protected, so can't be called from this utilility
+ * function.
+ *
+template <class T_CppObject, class... T_Arg>
+RefPtr<T_CppObject>
+make_refptr(T_Arg... arg)
{
- lhs.swap(rhs);
+ return RefPtr<T_CppObject>(new T_CppObject(arg...));
}
+*/
template <class T_CppObject>
RefPtr<T_CppObject>
make_refptr_for_instance(T_CppObject* object)
{
- return RefPtr<T_CppObject>(object);
+ return RefPtr<T_CppObject>(object, &RefPtrDeleter<T_CppObject>);
}
} // namespace Glib