X-Git-Url: http://git.tdb.fi/?a=blobdiff_plain;f=source%2Fgame%2Fhandle.h;h=b08bcf8e4f903028894702e8085df47174ce640f;hb=c3ac50ad3e79b26d1d99bd222a7e43adb86c2c1e;hp=d384f35c3c1fae6f29b1871a4c955079078d3e75;hpb=248d62f7240d342982ade65a510be912b867fe49;p=libs%2Fgame.git

diff --git a/source/game/handle.h b/source/game/handle.h
index d384f35..b08bcf8 100644
--- a/source/game/handle.h
+++ b/source/game/handle.h
@@ -23,13 +23,14 @@ protected:
 
 public:
 	Handle() = default;
-
-	static Handle from_object(T *o) { Handle h; h.ptr = o; return h; }
+	Handle(nullptr_t) { }
 
 	template<typename U>
 		requires std::is_base_of_v<T, U>
 	Handle(const Handle<U> &other): ptr(other.ptr) { }
 
+	static Handle from_object(T *o) { Handle h; h.ptr = o; return h; }
+
 	T *get() const { return ptr; }
 	T &operator*() const { return *ptr; }
 	T *operator->() const { return ptr; }
@@ -38,6 +39,13 @@ public:
 	bool operator==(const Handle &other) const = default;
 };
 
+template<typename T, typename U>
+	requires std::is_base_of_v<U, T>
+Handle<T> dynamic_handle_cast(Handle<U> h)
+{
+	return Handle<T>::from_object(dynamic_cast<T *>(h.get()));
+}
+
 } // namespace Msp::Game
 
 #endif