From fedafb9352c2877c5983e90834ffba0fff80ff15 Mon Sep 17 00:00:00 2001
From: Florent Rougon <f.rougon@free.fr>
Date: Thu, 9 Nov 2017 21:08:00 +0100
Subject: [PATCH] SGSharedPtr: add move constructor and move assignment
 operator

---
 simgear/structure/SGSharedPtr.hxx | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/simgear/structure/SGSharedPtr.hxx b/simgear/structure/SGSharedPtr.hxx
index 3afcfc91..181dcbb6 100644
--- a/simgear/structure/SGSharedPtr.hxx
+++ b/simgear/structure/SGSharedPtr.hxx
@@ -56,6 +56,8 @@ public:
   { get(_ptr); }
   SGSharedPtr(const SGSharedPtr& p) : _ptr(p.get())
   { get(_ptr); }
+  SGSharedPtr(SGSharedPtr&& other) : SGSharedPtr()
+  { swap(other); }
   template<typename U>
   SGSharedPtr(const SGSharedPtr<U>& p) : _ptr(p.get())
   { get(_ptr); }
@@ -64,9 +66,11 @@ public:
   { reset(p.lock().get()); }
   ~SGSharedPtr(void)
   { reset(); }
-  
-  SGSharedPtr& operator=(const SGSharedPtr& p)
-  { reset(p.get()); return *this; }
+
+  // This handles copy assignment using the copy-and-swap idiom, and also move
+  // assignment thanks to the move construtor.
+  SGSharedPtr& operator=(SGSharedPtr p)
+  { swap(p); return *this; }
   template<typename U>
   SGSharedPtr& operator=(const SGSharedPtr<U>& p)
   { reset(p.get()); return *this; }