WIP test specific QBind<Cur<QDataWriter>,_>

tests/QBind/QBind_impl.h

@@ -813,16 +813,16 @@ struct QBind<TResult, QMap<QString,T>> {
 
 #include <QtGui/qcolor.h>
 
-template<class TResult> //= Cursor
-struct QBind<TResult, QColor> {
-    static TResult bind(Val<TResult>&& v, QColor&& src) {
+template<>
+struct QBind<Cursor, QColor> {
+    static Cursor bind(Val<Cursor>&& v, QColor&& src) {
         return v.record()
             .bind("A",src.alpha())
             .bind("R",src.red  ())
             .bind("G",src.green())
             .bind("B",src.blue ());
     }
-    static TResult bind(Val<TResult>&& v, QColor& src) {
+    static Cursor bind(Val<Cursor>&& v, QColor& src) {
         return bind(std::move(v),QColor(src));
     }
 };

tests/QBind/QData_impl.h

@@ -49,6 +49,8 @@
 // //////////////////////////////////////////////////////////////////////////
 // QBind<QDataStream*,T> support using operator<< for all registered types and containers, or GenericBind with DataTag
 
+static const char* qmDataStreamVersion = "qmDataStreamVersion";
+
 //! \warning As with QDataStream, QDataWriter and QDataReader must:
 //! - bind the same C++ root data type (when unknown, QVariant can be used on both side)
 //! - use the same set of registered QMetaTypeIds with operator<< defined
@@ -57,7 +59,7 @@ class QDataWriter : public IWriter // allows runtime flexibility without BindNat
 {
     Q_DISABLE_COPY(QDataWriter)
 public:
-    QDataWriter(QDataStream* io) : io(io) { Q_ASSERT(io); }
+    QDataWriter(QDataStream* io) : io(io) { Q_ASSERT(io); version = QString::number(io->version()); }
 
     BindMode mode() const noexcept { return BindMode::Write; }
 
@@ -83,8 +85,11 @@ protected:
     bool _item(            ) { return true; }
     bool _item(QUtf8String&) { return true; } // record keys are implicit, maps should be serialized as a sequence of records with key and value items
     bool _item(       QName) { return true; } // for QBaseWriter
+
+    void _meta(QMetaData& m) { m[qmDataStreamVersion]=version; }
 private:
     QDataStream* io;
+    QString version;
 };
 template<typename T> struct BindSupport<QDataWriter,T> : BindSupport<IBind,T> {};
 // TODO BindNative other types that should bind specifically for compatibility with QDataStream
@@ -94,4 +99,30 @@ template<>           struct BindSupport<QDataWriter, QColor> : BindNative {};
 
 // Providing a general QDataReader may be deceiving because the QDataStream structure is implicit:
 // A reader is assumed to specify exactly what to read based on the stream origin and version
-// QVariant could be used though for parts which type are not known in advance
+// QVariant could be used though for parts which type are not known in advance such as the exact type of a message coming from a socket
+// And QDataStream version can be
+
+// ///////////////////////////////////////////////////////////////////////////
+// QBind<Cur<QDataWriter>,T> types that should bind specifically for compatibility with QDataStream
+
+template<>
+struct QBind<Cur<QDataWriter>, QColor> {
+    static Cur<QDataWriter> bind(Val<Cur<QDataWriter>>&& v, QColor&& src) {
+        QMetaData m;
+        v=v.meta(m);
+        if (m[qmDataStreamVersion].toInt()<7) {
+            v->reportError("Unsupported QDataStream.version()");
+            return v.null();
+        }
+        return v.sequence()
+            .bind(quint8 (src.spec ()))
+            .bind(quint16(src.alpha()))
+            .bind(quint16(src.red  ()))
+            .bind(quint16(src.green()))
+            .bind(quint16(src.blue ()));
+    }
+    static Cur<QDataWriter> bind(Val<Cur<QDataWriter>>&& v, QColor& src) {
+        return bind(std::move(v),QColor(src));
+    }
+};
+