From 165cfc7fcdcf8a818160dc47e5317368b04a8daa Mon Sep 17 00:00:00 2001
From: Ichthyostega <prg@ichthyostega.de>
Date: Fri, 17 Jul 2009 04:13:14 +0200
Subject: [PATCH] WIP allow some conversions, attempt to define the
 const_iterator properly

---
 src/lib/iter-adapter.hpp          | 65 ++++++++++++++++++++++++++-----
 src/lib/scoped-ptrvect.hpp        | 10 +++--
 tests/lib/scoped-ptrvect-test.cpp | 20 ++++++++++
 3 files changed, 82 insertions(+), 13 deletions(-)

diff --git a/src/lib/iter-adapter.hpp b/src/lib/iter-adapter.hpp
index 6744ed23c..4de2c994a 100644
--- a/src/lib/iter-adapter.hpp
+++ b/src/lib/iter-adapter.hpp
@@ -258,6 +258,16 @@ namespace lib {
         { }
       
       
+      /** allow copy,
+       *  when the underlying iterators
+       *  are compatible or convertible */
+      template<class I2>
+      RangeIter (I2 const& oIter)
+        : p_(oIter.getPos())
+        , e_(oIter.getEnd())
+        { }
+      
+      
       /* === lumiera forward iterator concept === */
       
       reference
@@ -299,6 +309,12 @@ namespace lib {
           return !isValid();
         }
       
+      
+      /** access wrapped STL iterator */
+      const IT&  getPos()  const { return p_; }
+      const IT&  getEnd()  const { return e_; }
+      
+      
     private:
       
       void
@@ -308,18 +324,13 @@ namespace lib {
             throw lumiera::error::Invalid ("Can't iterate further",
                   lumiera::error::LUMIERA_ERROR_ITER_EXHAUST);
         }
-      
-      
-      /// comparison operator is allowed to access the underlying impl iterator
-      template<class I1, class I2>
-      friend bool operator== (RangeIter<I1> const&, RangeIter<I2> const&);
     };
   
   
   
   /// Supporting equality comparisons...
   template<class I1, class I2>
-  bool operator== (RangeIter<I1> const& il, RangeIter<I2> const& ir)  { return (!il && !ir) || (il.p_ == ir.p_); }
+  bool operator== (RangeIter<I1> const& il, RangeIter<I2> const& ir)  { return (!il && !ir) || (il.getPos() == ir.getPos()); }
     
   template<class I1, class I2>
   bool operator!= (RangeIter<I1> const& il, RangeIter<I2> const& ir)  { return !(il == ir); }
@@ -374,6 +385,14 @@ namespace lib {
         { }
       
       
+      /** allow copy initialisation also
+       *  when the base iter types are convertible */
+      template<class I2>
+      PtrDerefIter (I2 const& oIter)
+        : i_(reinterpret_cast<IT const&> (oIter.getBase()))  /////////////////////////////TODO: properly guard this dangerous conversion by a traits template; the idea is to allow this conversion only for the initialisation of a "const iterator" from its sister type
+        { }
+      
+      
       /* === lumiera forward iterator concept === */
       
       reference
@@ -414,19 +433,45 @@ namespace lib {
         }
       
       
-      /// comparison operator is allowed to access the underlying impl iterator
-      template<class I1, class I2>
-      friend bool operator== (PtrDerefIter<I1> const&, PtrDerefIter<I2> const&);
+      /** access the wrapped implementation iterator */
+      IT const&
+      getBase()  const
+        {
+          return i_;
+        }
     };
   
   
   /// Supporting equality comparisons...
   template<class I1, class I2>
-  bool operator== (PtrDerefIter<I1> const& il, PtrDerefIter<I2> const& ir)  { return il.i_ == ir.i_; }
+  bool operator== (PtrDerefIter<I1> const& il, PtrDerefIter<I2> const& ir)  { return il.getBase() == ir.getBase(); }
     
   template<class I1, class I2>
   bool operator!= (PtrDerefIter<I1> const& il, PtrDerefIter<I2> const& ir)  { return !(il == ir); }
   
   
+  
+  /** 
+   * Helper for type rewritings:
+   * get the element type for an iterator like entity
+   */
+  template<class TY>
+  struct IterType;
+  
+  template<template<class,class> class Iter, class TY, class CON>
+  struct IterType<Iter<TY,CON> >
+    {
+      typedef CON Container;
+      typedef TY  ElemType;
+      
+      typedef typename RemovePtr<TY>::Type Type;
+      
+      template<class T2>
+      struct SimilarIter
+        {
+          typedef Iter<T2,CON> Type;
+        };
+    };
+  
 } // namespace lib
 #endif
diff --git a/src/lib/scoped-ptrvect.hpp b/src/lib/scoped-ptrvect.hpp
index d01992edc..e10704679 100644
--- a/src/lib/scoped-ptrvect.hpp
+++ b/src/lib/scoped-ptrvect.hpp
@@ -72,7 +72,8 @@ namespace lib {
     {
       typedef std::vector<T*> _Vec;
       typedef typename _Vec::iterator VIter;
-      typedef typename _Vec::const_iterator VcIter;
+//      typedef typename _Vec::const_iterator VcIter;
+      typedef typename IterType<VIter>::template SimilarIter<const T**>::Type VcIter;
       
       typedef RangeIter<VIter> RIter;
       typedef RangeIter<VcIter> RcIter;
@@ -83,6 +84,9 @@ namespace lib {
       typedef T &      reference;
       typedef T const& const_reference;
       
+      typedef typename IterType<VIter>::Type Tupe;
+            
+      
       
       ScopedPtrVect ()
         : _Vec()
@@ -155,8 +159,8 @@ namespace lib {
       
       iterator       begin()        { return       iterator (allPtrs()); }
       const_iterator begin()  const { return const_iterator (allPtrs()); }
-      iterator       end()          { return       iterator (); }
-      const_iterator end()    const { return const_iterator (); }
+      iterator       end()          { return       iterator ( RIter() ); }
+      const_iterator end()    const { return const_iterator (RcIter() ); }
       
       
       
diff --git a/tests/lib/scoped-ptrvect-test.cpp b/tests/lib/scoped-ptrvect-test.cpp
index d718ddc31..d8d051727 100644
--- a/tests/lib/scoped-ptrvect-test.cpp
+++ b/tests/lib/scoped-ptrvect-test.cpp
@@ -28,6 +28,13 @@
 #include "lib/scoped-ptrvect.hpp"
 #include "testdummy.hpp"
 
+//////////////////////////////////////////////TODO test code
+#include "lib/test/test-helper.hpp"
+using lib::test::showSizeof;
+#include <iostream>
+using std::cout;
+using std::endl;
+//////////////////////////////////////////////TODO test code
 
 namespace lib {
 namespace test{
@@ -111,6 +118,19 @@ namespace test{
                 ++check;
                 ++ii;
               }
+            check = 0;
+            
+///////////////////////////////////////////////////////////////////TODO test code
+            cout << showSizeof<VectD::Tupe> () << endl;
+///////////////////////////////////////////////////////////////////TODO test code
+            
+            VectD::const_iterator cii = holder.begin();
+            while (cii)
+              {
+                ASSERT (check == cii->getVal());
+                ++check;
+                ++cii;
+              }
           }
           ASSERT (0==checksum);
         }