QFutureInterface: mark the unused setContinuation() overloads as removed

This is a cleanup after the previous patch that introduced the new
setContinuation() overloads. The old API cannot be used correctly with
the new approach that requires to always set a continuation type, so
let's mark it as removed.

Technically, this change is SiC. However, QFutureInterfaceBase was
never documented as a public class, so users are not supposed to derive
from it and should not use setContinuation() methods directly.

Task-number: QTBUG-130662
Change-Id: Idf3d9f5de00a7c4ac34ee3dde1d58902e3a27904
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>

src/corelib/compat/removed_api.cpp

@@ -1380,6 +1380,46 @@ QUuid::Version QUuid::version() const noexcept
 
 #if QT_CORE_REMOVED_SINCE(6, 10)
 
+#if QT_CONFIG(future)
+#include "qfuture.h" // for ContinuationWrapper
+#include "qfutureinterface.h"
+
+void QtPrivate::watchContinuationImpl(const QObject *context,
+                                      QtPrivate::QSlotObjectBase *slotObj,
+                                      QFutureInterfaceBase &fi)
+{
+    Q_ASSERT(context);
+    Q_ASSERT(slotObj);
+
+    auto slot = QtPrivate::SlotObjUniquePtr(slotObj);
+
+    // That is now a double-inderection, because the setContinuation() overload
+    // also uses QSlotObjectBase approach. But that's a solution for backwards
+    // compatibility, so should be fine.
+    // We pass a default-constructed QVariant() and an Unknown type, because
+    // that's effectively the same as passing a nullptr continuationData, and
+    // that's what the old code was doing.
+    fi.setContinuation(context, QtPrivate::ContinuationWrapper([slot = std::move(slot)]()
+    {
+        void *args[] = { nullptr }; // for `void` return value
+        slot->call(nullptr, args);
+    }), QVariant(), QFutureInterfaceBase::ContinuationType::Unknown);
+}
+
+void QFutureInterfaceBase::setContinuation(std::function<void(const QFutureInterfaceBase &)> func)
+{
+    setContinuation(std::move(func), nullptr);
+}
+
+void QFutureInterfaceBase::setContinuation(std::function<void(const QFutureInterfaceBase &)> func,
+                                           QFutureInterfaceBasePrivate *continuationFutureData)
+{
+    // Backwards compatibility - the continuation data was used for
+    // then-continuations
+    setContinuation(std::move(func), continuationFutureData, ContinuationType::Then);
+}
+#endif // QT_CONFIG(future)
+
 #include "qlogging.h"
 
 QNoDebug QMessageLogger::noDebug() const noexcept

src/corelib/thread/qfutureinterface.cpp

@@ -55,27 +55,6 @@ signals:
     void run();
 };
 
-void QtPrivate::watchContinuationImpl(const QObject *context, QSlotObjectBase *slotObj,
-                                      QFutureInterfaceBase &fi)
-{
-    Q_ASSERT(context);
-    Q_ASSERT(slotObj);
-
-    auto slot = SlotObjUniquePtr(slotObj);
-
-    // That is now a double-inderection, because the setContinuation() overload
-    // also uses QSlotObjectBase approach. But that's a solution for backwards
-    // compatibility, so should be fine.
-    // We pass a default-constructed QVariant() and an Unknown type, because
-    // that's effectively the same as passing a nullptr continuationData, and
-    // that's what the old code was doing.
-    fi.setContinuation(context, ContinuationWrapper([slot = std::move(slot)]()
-    {
-        void *args[] = { nullptr }; // for `void` return value
-        slot->call(nullptr, args);
-    }), QVariant(), QFutureInterfaceBase::ContinuationType::Unknown);
-}
-
 QFutureCallOutInterface::~QFutureCallOutInterface()
     = default;
 
@@ -846,19 +825,6 @@ void QFutureInterfaceBasePrivate::setState(QFutureInterfaceBase::State newState)
     state.storeRelaxed(newState);
 }
 
-void QFutureInterfaceBase::setContinuation(std::function<void(const QFutureInterfaceBase &)> func)
-{
-    setContinuation(std::move(func), nullptr);
-}
-
-void QFutureInterfaceBase::setContinuation(std::function<void(const QFutureInterfaceBase &)> func,
-                                           QFutureInterfaceBasePrivate *continuationFutureData)
-{
-    // Backwards compatibility - the continuation data was used for
-    // then-continuations
-    setContinuation(std::move(func), continuationFutureData, ContinuationType::Then);
-}
-
 void QFutureInterfaceBase::setContinuation(std::function<void (const QFutureInterfaceBase &)> func,
                                            void *continuationFutureData, ContinuationType type)
 {

src/corelib/thread/qfutureinterface.h

@@ -6,6 +6,7 @@
 
 #include <QtCore/qmutex.h>
 #include <QtCore/qresultstore.h>
+#include <QtCore/qtcoreexports.h>
 #ifndef QT_NO_EXCEPTIONS
 #include <exception>
 #endif
@@ -40,9 +41,11 @@ template<class Function, class ResultType>
 class FailureHandler;
 #endif
 
+#if QT_CORE_REMOVED_SINCE(6, 10)
 void Q_CORE_EXPORT watchContinuationImpl(const QObject *context,
                                          QtPrivate::QSlotObjectBase *slotObj,
                                          QFutureInterfaceBase &fi);
+#endif // QT_CORE_REMOVED_SINCE(6, 10)
 }
 
 class Q_CORE_EXPORT QFutureInterfaceBase
@@ -182,8 +185,10 @@ private:
     friend class QtPrivate::FailureHandler;
 #endif
 
+#if QT_CORE_REMOVED_SINCE(6, 10)
     friend Q_CORE_EXPORT void QtPrivate::watchContinuationImpl(
             const QObject *context, QtPrivate::QSlotObjectBase *slotObj, QFutureInterfaceBase &fi);
+#endif // QT_CORE_REMOVED_SINCE(6, 10)
 
     template<class T>
     friend class QPromise;
@@ -197,9 +202,11 @@ protected:
         OnCanceled,
     };
 
+#if QT_CORE_REMOVED_SINCE(6, 10)
     void setContinuation(std::function<void(const QFutureInterfaceBase &)> func);
     void setContinuation(std::function<void(const QFutureInterfaceBase &)> func,
                          QFutureInterfaceBasePrivate *continuationFutureData);
+#endif // QT_CORE_REMOVED_SINCE(6, 10)
     void setContinuation(std::function<void(const QFutureInterfaceBase &)> func,
                          void *continuationFutureData, ContinuationType type);
     void setContinuation(const QObject *context, std::function<void()> func,