From 89c30cd37cc42bfac25ec3edc16b1ac1e42c6309 Mon Sep 17 00:00:00 2001
From: danshapero <shapero.daniel@gmail.com>
Date: Thu, 31 Mar 2016 20:53:55 -0700
Subject: [PATCH] Added move constructor to Subscriptor

A subscriptor can only be moved if there are no other objects
subscribing to it. This condition is already checked in a sensible
way in the destructor for Subscriptor, so rather than add a bunch
of boilerplate, the move constructor just invokes the destructor.
---
 include/deal.II/base/subscriptor.h | 10 ++++++++++
 source/base/subscriptor.cc         | 23 +++++++++++++++++++++++
 2 files changed, 33 insertions(+)

diff --git a/include/deal.II/base/subscriptor.h b/include/deal.II/base/subscriptor.h
index 17023d8ef3..6f968c7bf7 100644
--- a/include/deal.II/base/subscriptor.h
+++ b/include/deal.II/base/subscriptor.h
@@ -69,6 +69,16 @@ public:
    */
   Subscriptor(const Subscriptor &);
 
+#ifdef DEAL_II_WITH_CXX11
+  /**
+   * Move constructor.
+   *
+   * An object inheriting from Subscriptor can only be moved if no other
+   * objects are subscribing to it.
+   */
+  Subscriptor(Subscriptor&&);
+#endif
+
   /**
    * Destructor, asserting that the counter is zero.
    */
diff --git a/source/base/subscriptor.cc b/source/base/subscriptor.cc
index c3a61421ba..07240b88e9 100644
--- a/source/base/subscriptor.cc
+++ b/source/base/subscriptor.cc
@@ -62,6 +62,22 @@ Subscriptor::Subscriptor (const Subscriptor &)
 {}
 
 
+
+#ifdef DEAL_II_WITH_CXX11
+Subscriptor::Subscriptor (Subscriptor &&subscriptor)
+  :
+  counter(0),
+  object_info (subscriptor.object_info)
+{
+  // Explicitly invoke the destructor of `Subscriptor` for the object
+  // to be moved from in order to guarantee that we're not moving an
+  // object that has subscriptions.
+  subscriptor.~Subscriptor();
+}
+#endif
+
+
+
 Subscriptor::~Subscriptor ()
 {
   // check whether there are still
@@ -136,6 +152,13 @@ Subscriptor::~Subscriptor ()
   // do_unsubscribe below that the
   // object is unused now.
   counter = 0;
+
+#ifdef DEAL_II_WITH_CXX11
+  object_info = nullptr;
+#else
+  object_info = 0;
+#endif
+
 #endif
 }
 
-- 
2.39.5