From 2409d46d4c165a9bac7cb69547a88c3a546994c5 Mon Sep 17 00:00:00 2001
From: Paul Licameli <paul.licameli@audacityteam.org>
Date: Wed, 10 Jan 2018 23:58:36 -0500
Subject: [PATCH] Prohibit copy of TrackList, no longer needed; allow swap and
 move

---
 src/Track.cpp | 27 ---------------------------
 src/Track.h   | 15 ++++++---------
 2 files changed, 6 insertions(+), 36 deletions(-)

diff --git a/src/Track.cpp b/src/Track.cpp
index 8e387d011..a65da94b8 100644
--- a/src/Track.cpp
+++ b/src/Track.cpp
@@ -792,15 +792,6 @@ std::shared_ptr<TrackList> TrackList::Create()
    return result;
 }
 
-TrackList& TrackList::operator= (const TrackList &that)
-{
-   if (this != &that) {
-      this->Clear();
-      DoAssign(that);
-   }
-   return *this;
-}
-
 TrackList &TrackList::operator= (TrackList &&that)
 {
    if (this != &that) {
@@ -810,24 +801,6 @@ TrackList &TrackList::operator= (TrackList &&that)
    return *this;
 }
 
-void TrackList::DoAssign(const TrackList &that)
-{
-   auto copyLOT = [](
-      ListOfTracks &dst, const std::weak_ptr< TrackList > &self,
-      const ListOfTracks &src )
-   {
-      for (const auto &ptr : src)
-         dst.push_back(
-            ListOfTracks::value_type{ ptr->Duplicate().release() } );
-      for (auto it = dst.begin(), last = dst.end(); it != last; ++it)
-         (*it)->SetOwner(self, it);
-   };
-   copyLOT( *this, mSelf, that );
-   copyLOT( this->mPendingAdditions, mSelf, that.mPendingAdditions );
-   copyLOT( this->mPendingUpdates, mSelf, that.mPendingUpdates );
-   mUpdaters = that.mUpdaters;
-}
-
 void TrackList::Swap(TrackList &that)
 {
    auto SwapLOTs = [](
diff --git a/src/Track.h b/src/Track.h
index 89842228e..0c5d5c7d1 100644
--- a/src/Track.h
+++ b/src/Track.h
@@ -659,8 +659,13 @@ class TrackList final : public wxEvtHandler, public ListOfTracks
    // Create an empty TrackList
    TrackList();
 
+   // Disallow copy
    TrackList(const TrackList &that) = delete;
-   TrackList(TrackList &&that) = delete;
+   TrackList &operator= (const TrackList&) = delete;
+
+   // Allow move
+   TrackList(TrackList &&that) : TrackList() { Swap(that); }
+   TrackList& operator= (TrackList&&);
 
    void clear() = delete;
 
@@ -668,12 +673,6 @@ class TrackList final : public wxEvtHandler, public ListOfTracks
    // Create an empty TrackList
    static std::shared_ptr<TrackList> Create();
 
-   // Allow copy -- a deep copy that duplicates all tracks
-   TrackList &operator= (const TrackList &that);
-
-   // Allow move
-   TrackList& operator= (TrackList&&);
-
    // Move is defined in terms of Swap
    void Swap(TrackList &that);
 
@@ -831,8 +830,6 @@ private:
       }
    }
 
-   void DoAssign(const TrackList &that);
-       
    void RecalcPositions(TrackNodePointer node);
    void PermutationEvent();
    void DeletionEvent();