From d25337a631a0fb61afc12ebe7c34e266e1a52ca4 Mon Sep 17 00:00:00 2001
From: Marc Mutz <marc.mutz@qt.io>
Date: Tue, 28 Mar 2023 10:54:59 +0200
Subject: [PATCH] QFutureInterface: Extract Method reportAndEmplaceResult()
 from reportAndMoveResult()
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This will be the building block for emplacement support in QPromise.

Task-number: QTBUG-112270
Change-Id: Ie267e76fe078a8f7b3ef8c7e0d2abfcd22062ff2
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
---
 src/corelib/thread/qfutureinterface.h | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/corelib/thread/qfutureinterface.h b/src/corelib/thread/qfutureinterface.h
index 7e682e69b6..ecb0f5b7ea 100644
--- a/src/corelib/thread/qfutureinterface.h
+++ b/src/corelib/thread/qfutureinterface.h
@@ -236,6 +236,8 @@ public:
 
     inline QFuture<T> future(); // implemented in qfuture.h
 
+    template <typename...Args, std::enable_if_t<std::is_constructible_v<T, Args...>, bool> = true>
+    inline bool reportAndEmplaceResult(int index, Args&&...args);
     inline bool reportResult(const T *result, int index = -1);
     inline bool reportAndMoveResult(T &&result, int index = -1);
     inline bool reportResult(T &&result, int index = -1);
@@ -301,7 +303,8 @@ inline bool QFutureInterface<T>::reportResult(const T *result, int index)
 }
 
 template<typename T>
-bool QFutureInterface<T>::reportAndMoveResult(T &&result, int index)
+template<typename...Args, std::enable_if_t<std::is_constructible_v<T, Args...>, bool>>
+bool QFutureInterface<T>::reportAndEmplaceResult(int index, Args&&...args)
 {
     QMutexLocker<QMutex> locker{&mutex()};
     if (queryState(Canceled) || queryState(Finished))
@@ -311,13 +314,19 @@ bool QFutureInterface<T>::reportAndMoveResult(T &&result, int index)
     QtPrivate::ResultStoreBase &store = resultStoreBase();
 
     const int oldResultCount = store.count();
-    const int insertIndex = store.moveResult(index, std::move(result));
+    const int insertIndex = store.emplaceResult<T>(index, std::forward<Args>(args)...);
     // Let's make sure it's not in pending results.
     if (insertIndex != -1 && (!store.filterMode() || oldResultCount < store.count()))
         reportResultsReady(insertIndex, store.count());
     return insertIndex != -1;
 }
 
+template<typename T>
+bool QFutureInterface<T>::reportAndMoveResult(T &&result, int index)
+{
+    return reportAndEmplaceResult(index, std::move(result));
+}
+
 template<typename T>
 bool QFutureInterface<T>::reportResult(T &&result, int index)
 {