From cbf90b6304b96158e239c9b58555109f8b5ca67a Mon Sep 17 00:00:00 2001
From: Marc Mutz <marc.mutz@qt.io>
Date: Tue, 13 Feb 2024 11:57:39 +0100
Subject: QVarLengthArray: give the default Prealloc a name

... and use that in QVarLengthFlatMap's definition in lieu of a magic
constant.

Amends d4611ba3a5b46ee790e6c790ef6c3d771d3507ee.

Pick-to: 6.2
Change-Id: I369f31b643789075ef6c14669b8b794ed0b3bbb1
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
(cherry picked from commit c30195a95e751552a39f99dd5833ebf722d11bc1)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
(cherry picked from commit aea4e9788ab45df63dc14000321c7743dc9f3ab2)
(cherry picked from commit 823a9677b42ecf75baf558f250a1bd0a79a89322)
---
 src/corelib/tools/qcontainerfwd.h | 3 ++-
 src/corelib/tools/qflatmap_p.h    | 4 +++-
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/corelib/tools/qcontainerfwd.h b/src/corelib/tools/qcontainerfwd.h
index 67b8d7f4529..dfd7bedc1f5 100644
--- a/src/corelib/tools/qcontainerfwd.h
+++ b/src/corelib/tools/qcontainerfwd.h
@@ -25,7 +25,8 @@ using QPair = std::pair<T1, T2>;
 template <typename T> class QQueue;
 template <typename T> class QSet;
 template <typename T> class QStack;
-template <typename T, qsizetype Prealloc = 256> class QVarLengthArray;
+constexpr qsizetype QVarLengthArrayDefaultPrealloc = 256;
+template <typename T, qsizetype Prealloc = QVarLengthArrayDefaultPrealloc> class QVarLengthArray;
 template <typename T> class QList;
 class QString;
 #ifndef Q_QDOC
diff --git a/src/corelib/tools/qflatmap_p.h b/src/corelib/tools/qflatmap_p.h
index 754b6c3a7a9..b3f42317925 100644
--- a/src/corelib/tools/qflatmap_p.h
+++ b/src/corelib/tools/qflatmap_p.h
@@ -1099,7 +1099,9 @@ private:
     containers c;
 };
 
-template<class Key, class T, qsizetype N = 256, class Compare = std::less<Key>>
+template <class Key, class T,
+          qsizetype N = QVarLengthArrayDefaultPrealloc,
+          class Compare = std::less<Key>>
 using QVarLengthFlatMap = QFlatMap<Key, T, Compare, QVarLengthArray<Key, N>, QVarLengthArray<T, N>>;
 
 QT_END_NAMESPACE
-- 
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