Invert include dependencies between QList and QVector

This is a very slight source incompatibility, but required as
a preparation for Qt 6, where QList should inherit QVector or
share the implementation with it.

This requires some special work to correctly instantiate and
export QVector<QPoint> from Qt Core on MSVC.

Change-Id: I1d042c5fafdde7afe59409eda2580871d4832fcd
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/tools/qlist.cpp

@@ -47,6 +47,23 @@
 
 QT_BEGIN_NAMESPACE
 
+/*
+   ### Qt 5:
+   ### This needs to be removed for next releases of Qt. It is a workaround for vc++ because
+   ### Qt exports QPolygon and QPolygonF that inherit QVector<QPoint> and
+   ### QVector<QPointF> respectively.
+*/
+
+#if defined(Q_CC_MSVC) && defined(QT_BUILD_CORE_LIB)
+QT_BEGIN_INCLUDE_NAMESPACE
+#include <QtCore/qpoint.h>
+QT_END_INCLUDE_NAMESPACE
+
+template class Q_CORE_EXPORT QVector<QPointF>;
+template class Q_CORE_EXPORT QVector<QPoint>;
+#endif
+
+
 /*
     QList as an array-list combines the easy-of-use of a random
     access interface with fast list operations and the low memory

src/corelib/tools/qlist.h

@@ -45,6 +45,7 @@
 #include <QtCore/qrefcount.h>
 #include <QtCore/qarraydata.h>
 #include <QtCore/qhashfunctions.h>
+#include <QtCore/qvector.h>
 
 #include <iterator>
 #include <list>
@@ -1051,6 +1052,37 @@ inline int QList<T>::count_impl(const T &t, QListData::ArrayCompatibleLayout) co
                           t));
 }
 
+template <typename T>
+Q_OUTOFLINE_TEMPLATE QVector<T> QList<T>::toVector() const
+{
+    QVector<T> result(size());
+    for (int i = 0; i < size(); ++i)
+        result[i] = at(i);
+    return result;
+}
+
+template <typename T>
+QList<T> QList<T>::fromVector(const QVector<T> &vector)
+{
+    return vector.toList();
+}
+
+template <typename T>
+Q_OUTOFLINE_TEMPLATE QList<T> QVector<T>::toList() const
+{
+    QList<T> result;
+    result.reserve(size());
+    for (int i = 0; i < size(); ++i)
+        result.append(at(i));
+    return result;
+}
+
+template <typename T>
+QVector<T> QVector<T>::fromList(const QList<T> &list)
+{
+    return list.toVector();
+}
+
 Q_DECLARE_SEQUENTIAL_ITERATOR(List)
 Q_DECLARE_MUTABLE_SEQUENTIAL_ITERATOR(List)
 

src/corelib/tools/qvector.h

@@ -42,7 +42,6 @@
 
 #include <QtCore/qalgorithms.h>
 #include <QtCore/qiterator.h>
-#include <QtCore/qlist.h>
 #include <QtCore/qrefcount.h>
 #include <QtCore/qarraydata.h>
 #include <QtCore/qhashfunctions.h>
@@ -968,37 +967,6 @@ Q_OUTOFLINE_TEMPLATE QVector<T> QVector<T>::mid(int pos, int len) const
     return midResult;
 }
 
-template <typename T>
-Q_OUTOFLINE_TEMPLATE QList<T> QVector<T>::toList() const
-{
-    QList<T> result;
-    result.reserve(size());
-    for (int i = 0; i < size(); ++i)
-        result.append(at(i));
-    return result;
-}
-
-template <typename T>
-Q_OUTOFLINE_TEMPLATE QVector<T> QList<T>::toVector() const
-{
-    QVector<T> result(size());
-    for (int i = 0; i < size(); ++i)
-        result[i] = at(i);
-    return result;
-}
-
-template <typename T>
-QVector<T> QVector<T>::fromList(const QList<T> &list)
-{
-    return list.toVector();
-}
-
-template <typename T>
-QList<T> QList<T>::fromVector(const QVector<T> &vector)
-{
-    return vector.toList();
-}
-
 Q_DECLARE_SEQUENTIAL_ITERATOR(Vector)
 Q_DECLARE_MUTABLE_SEQUENTIAL_ITERATOR(Vector)
 
@@ -1046,20 +1014,12 @@ inline bool operator>=(const QVector<T> &lhs, const QVector<T> &rhs)
    ### QVector<QPointF> respectively.
 */
 
-#ifdef Q_CC_MSVC
+#if defined(Q_CC_MSVC) && !defined(QT_BUILD_CORE_LIB)
 QT_BEGIN_INCLUDE_NAMESPACE
 #include <QtCore/qpoint.h>
 QT_END_INCLUDE_NAMESPACE
-
+extern template class Q_CORE_EXPORT QVector<QPointF>;
-#ifndef Q_TEMPLATE_EXTERN
+extern template class Q_CORE_EXPORT QVector<QPoint>;
-#if defined(QT_BUILD_CORE_LIB)
-#define Q_TEMPLATE_EXTERN
-#else
-#define Q_TEMPLATE_EXTERN extern
-#endif
-#endif
-Q_TEMPLATE_EXTERN template class Q_CORE_EXPORT QVector<QPointF>;
-Q_TEMPLATE_EXTERN template class Q_CORE_EXPORT QVector<QPoint>;
 #endif
 
 QVector<uint> QStringView::toUcs4() const { return QtPrivate::convertToUcs4(*this); }