From 1fa7a4a43769e1bc0571d52f2c022409653ea745 Mon Sep 17 00:00:00 2001
From: Ichthyostega <prg@ichthyostega.de>
Date: Fri, 3 Jul 2015 18:16:54 +0200
Subject: [PATCH] WIP: define the full set of default copy operations
 explicitly

on a second thought, this "workaround" does not look so bad,
due to the C++11 feature to request the default implementation explicitly.
Maybe we'll never need a generic solution for these cases
---
 src/lib/diff/gen-node.hpp | 50 ++++++++++++++++-----------------------
 wiki/thinkPad.ichthyo.mm  | 34 +++++++++++++++++++++++++-
 2 files changed, 53 insertions(+), 31 deletions(-)

diff --git a/src/lib/diff/gen-node.hpp b/src/lib/diff/gen-node.hpp
index 2f6f08aa7..6c5e81b49 100644
--- a/src/lib/diff/gen-node.hpp
+++ b/src/lib/diff/gen-node.hpp
@@ -121,33 +121,6 @@ namespace diff{
   
   using std::string;
   
-  namespace {//////TODO this is a prototype, to be factored out
-    
-    template<typename X, class SELF>
-    struct ShaddowCopyCtor
-      {
-        operator bool()  const { return true; }
-      };
-    
-    template<class SELF>
-    struct ShaddowCopyCtor<SELF, SELF>
-      {
-        // no bool conversion -> substitution fails.
-      };
-    template<class SELF>
-    struct ShaddowCopyCtor<SELF&, SELF>
-      {
-        // no bool conversion -> substitution fails.
-      };
-    template<class SELF>
-    struct ShaddowCopyCtor<const SELF, SELF>
-      {
-        // no bool conversion -> substitution fails.
-      };
-    
-  }//(End) copy shaddowing solution
-  
-  
   class GenNode;
   
   using Rec = Record<GenNode>;
@@ -173,11 +146,19 @@ namespace diff{
     {
     public:
       template<typename X>
-      DataCap(X&& x,   bool = ShaddowCopyCtor<X, DataCap>())
+      DataCap(X&& x)
         : Variant<DataValues>(std::forward<X>(x))
         { }
       
                                        ////////////////////////TICKET #963  Forwarding shadows copy operations -- generic solution??
+      DataCap(DataCap const&) =default;
+      DataCap(DataCap&&)      =default;
+      DataCap(DataCap& o)
+        : DataCap((DataCap const&)o)
+        { }
+      
+      DataCap& operator= (DataCap const&)  =default;
+      DataCap& operator= (DataCap&&)       =default;
     };
   
   
@@ -208,7 +189,7 @@ namespace diff{
       
       
       template<typename X>
-      GenNode(X&& val,   bool = ShaddowCopyCtor<X, GenNode>())
+      GenNode(X&& val)
         : idi(&val, buildChildID<X>())
         , data(std::forward<X>(val))
         { }
@@ -227,7 +208,16 @@ namespace diff{
         : GenNode(string(text))
         { }
       
-      // default copy assignable
+                                       ////////////////////////TICKET #963  Forwarding shadows copy operations -- generic solution??
+      GenNode(GenNode const&)  =default;
+      GenNode(GenNode&&)       =default;
+      GenNode(GenNode& o)
+        : GenNode((GenNode const&)o)
+        { }
+      
+      GenNode& operator= (GenNode const&)  =default;
+      GenNode& operator= (GenNode&&)       =default;
+      
       
       
       bool
diff --git a/wiki/thinkPad.ichthyo.mm b/wiki/thinkPad.ichthyo.mm
index 8357203dc..0714b3e3a 100644
--- a/wiki/thinkPad.ichthyo.mm
+++ b/wiki/thinkPad.ichthyo.mm
@@ -46,7 +46,39 @@
 </node>
 </node>
 <node CREATED="1434128174030" ID="ID_1395250463" MODIFIED="1434128176521" TEXT="Variant"/>
-<node CREATED="1434128217645" ID="ID_1790054544" MODIFIED="1434128220257" TEXT="Monade"/>
+<node CREATED="1434128217645" ID="ID_1790054544" MODIFIED="1434128220257" TEXT="Monade">
+<node CREATED="1435932580854" ID="ID_1307223527" MODIFIED="1435932586137" TEXT="Daten einwickeln">
+<node CREATED="1435932589853" ID="ID_180643071" MODIFIED="1435932595665" TEXT="ctor forward"/>
+<node CREATED="1435932598197" ID="ID_951223738" MODIFIED="1435932608318" TEXT="Problem mit copy ctor">
+<icon BUILTIN="messagebox_warning"/>
+<node CREATED="1435932667701" HGAP="22" ID="ID_1069242347" MODIFIED="1435932709198" TEXT="Copy matcht generischen ctor" VSHIFT="-9">
+<icon BUILTIN="idea"/>
+<node CREATED="1435932714261" ID="ID_1395890846" MODIFIED="1435932719281" TEXT="gleiches Problem schon bei Variant"/>
+<node CREATED="1435932719709" ID="ID_188423010" MODIFIED="1435932783846" TEXT="dort explizit gemacht, da komplex">
+<richcontent TYPE="NOTE"><html>
+  <head>
+    
+  </head>
+  <body>
+    <p>
+      ich hatte damals beim Variant und zugeh&#246;rigen Buffer die Sorge,
+    </p>
+    <p>
+      da&#223; ich die Implikationen einer generischen L&#246;sung nicht durchdringen kann.
+    </p>
+    <p>
+      Und ich wollte keine Zeit auf einen exzessiven Unit-Test verwenden
+    </p>
+  </body>
+</html>
+</richcontent>
+</node>
+</node>
+<node CREATED="1435932611653" ID="ID_1701726752" MODIFIED="1435932628945" TEXT="Ansatz-1 (einfach): explizit"/>
+<node CREATED="1435932629517" ID="ID_1935900779" MODIFIED="1435932661977" TEXT="Ansatz-2: Selbst-Typ ausblenden"/>
+</node>
+</node>
+</node>
 <node CREATED="1434128176918" ID="ID_863330674" MODIFIED="1434128195333" TEXT="Record">
 <node CREATED="1434128198957" ID="ID_1224215957" MODIFIED="1434128203817" TEXT="Konstuktor">
 <node CREATED="1434421381345" ID="ID_752165044" MODIFIED="1434421402225" TEXT="DSL zur Daten-Definition"/>