Fixed compilation of wxVector<T> with VC6:

* reverted VC6 hack in wxIf<>, using helper struct instead of typedef
  didn't fix compilation, only caused the compiler to crash instead
  of emitting semi-useful errors
* changed wxVector to use typedef for Ops class instead of privately
  deriving from wxIf<...>::value; this is enough to make VC6 happy



git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@51471 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/meta/if.h

@@ -30,19 +30,7 @@ struct wxIfImpl
 // without this skeleton it doesn't recognize Result as a class at all below
 #if defined(__VISUALC__) && !wxCHECK_VISUALC_VERSION(7)
 {
-    template<typename TTrue, typename TFalse> struct Result
+    template<typename TTrue, typename TFalse> struct Result {};
-    {
-        // unfortunately we also need to define value here because otherwise
-        // Result::value is not recognized as a class neither and it has to be
-        // complete too -- at least make it unusable because it really, really
-        // should never be used
-        class value
-        {
-        private:
-            value();
-            ~value();
-        };
-    };
 }
 #endif // VC++ <= 6
 ;
@@ -53,11 +41,7 @@ struct wxIfImpl<true>
 {
     template<typename TTrue, typename TFalse> struct Result
     {
-#if defined(__VISUALC__) && !wxCHECK_VISUALC_VERSION(7)
-        struct value : TTrue { };
-#else
         typedef TTrue value;
-#endif
     };
 };
 
@@ -67,11 +51,7 @@ struct wxIfImpl<false>
 {
     template<typename TTrue, typename TFalse> struct Result
     {
-#if defined(__VISUALC__) && !wxCHECK_VISUALC_VERSION(7)
-        struct value : TFalse { };
-#else
         typedef TFalse value;
-#endif
     };
 };
 
@@ -85,15 +65,9 @@ struct wxIfImpl<false>
 template<bool Cond, typename TTrue, typename TFalse>
 struct wxIf
 {
-#if defined(__VISUALC__) && !wxCHECK_VISUALC_VERSION(7)
-    // notice that value can't be a typedef, VC6 refuses to use it as a base
-    // class in this case
-    struct value : wxPrivate::wxIfImpl<Cond>::Result<TTrue, TFalse>::value { };
-#else // !VC6++
     typedef typename wxPrivate::wxIfImpl<Cond>
                      ::template Result<TTrue, TFalse>::value
             value;
-#endif
 };
 
 #endif // _WX_META_IF_H_

include/wx/vector.h

@@ -102,12 +102,19 @@ struct wxVectorMemOpsGeneric
 
 template<typename T>
 class wxVector
-    // this cryptic expression means "derive from wxVectorMemOpsMovable if
-    // type T is movable type, otherwise derive from wxVectorMemOpsGeneric
-    : private wxIf< wxIsMovable<T>::value,
-                    wxPrivate::wxVectorMemOpsMovable<T>,
-                    wxPrivate::wxVectorMemOpsGeneric<T> >::value
 {
+private:
+    // Tthis cryptic expression means "typedef Ops to wxVectorMemOpsMovable if
+    // type T is movable type, otherwise to wxVectorMemOpsGeneric".
+    //
+    // Note that we use typedef instead of privately deriving from this (which
+    // would allowed us to omit "Ops::" prefixes below) to keep VC6 happy,
+    // it can't compile code that derives from wxIf<...>::value.
+    typedef typename wxIf< wxIsMovable<T>::value,
+                           wxPrivate::wxVectorMemOpsMovable<T>,
+                           wxPrivate::wxVectorMemOpsGeneric<T> >::value
+            Ops;
+
 public:
     typedef size_t size_type;
     typedef T value_type;
@@ -135,7 +142,7 @@ public:
             m_values[i].~T();
         }
 
-        Free(m_values);
+        Ops::Free(m_values);
         m_values = NULL;
         m_size = m_capacity = 0;
     }
@@ -156,7 +163,7 @@ public:
         if ( m_capacity + increment > n )
             n = m_capacity + increment;
 
-        m_values = Realloc(m_values, n * sizeof(value_type), m_size);
+        m_values = Ops::Realloc(m_values, n * sizeof(value_type), m_size);
         m_capacity = n;
     }
 
@@ -239,7 +246,7 @@ public:
         // the way:
         if ( after > 0 )
         {
-            MemmoveForward(m_values + idx + 1, m_values + idx, after);
+            Ops::MemmoveForward(m_values + idx + 1, m_values + idx, after);
         }
 
 #if wxUSE_EXCEPTIONS
@@ -258,7 +265,7 @@ public:
             // back to their original positions in m_values
             if ( after > 0 )
             {
-                MemmoveBackward(m_values + idx, m_values + idx + 1, after);
+                Ops::MemmoveBackward(m_values + idx, m_values + idx + 1, after);
             }
 
             throw; // rethrow the exception
@@ -295,7 +302,7 @@ public:
         // once that's done, move following elements over to the freed space:
         if ( after > 0 )
         {
-            MemmoveBackward(m_values + idx, m_values + idx + count, after);
+            Ops::MemmoveBackward(m_values + idx, m_values + idx + count, after);
         }
 
         m_size -= count;