From ddc6eddf77a5b56243eaa56dec1c5e098353cde9 Mon Sep 17 00:00:00 2001
From: Amir Masoud Abdol <amir.abdol@qt.io>
Date: Mon, 1 May 2023 10:58:24 +0200
Subject: [PATCH] Resolve symbol ambiguity when building with Unity Build

In unity build, we may get `error: reference to 'detail' is ambiguous`
between the `detail` namespace defined in `qpropertyprivate.h`, and
`qflatmap_p.h`. For now, this causes an issue during the compilation of
`qcalendar.cpp` and it may occur in other places where qflatmap is
included.

Task-number: QTBUG-109394
Change-Id: Ie4bbb66543d26a5db58488e924333d98ce0adebf
Reviewed-by: Joerg Bornemann <joerg.bornemann@qt.io>
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
(cherry picked from commit a0923d5d3a4fa1dd03075aa50766224ac1d6e103)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
---
 src/corelib/tools/qflatmap_p.h | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/corelib/tools/qflatmap_p.h b/src/corelib/tools/qflatmap_p.h
index 68ab567439e..7fce7c43af0 100644
--- a/src/corelib/tools/qflatmap_p.h
+++ b/src/corelib/tools/qflatmap_p.h
@@ -83,6 +83,7 @@ public:
     }
 };
 
+namespace qflatmap {
 namespace detail {
 template <class T>
 class QFlatMapMockPointer
@@ -100,6 +101,7 @@ public:
     }
 };
 } // namespace detail
+} // namespace qflatmap
 
 template<class Key, class T, class Compare = std::less<Key>, class KeyContainer = QList<Key>,
          class MappedContainer = QList<T>>
@@ -107,8 +109,9 @@ class QFlatMap : private QFlatMapValueCompare<Key, T, Compare>
 {
     static_assert(std::is_nothrow_destructible_v<T>, "Types with throwing destructors are not supported in Qt containers.");
 
-    template <class U>
-    using mock_pointer = detail::QFlatMapMockPointer<U>;
+    template<class U>
+    using mock_pointer = qflatmap::detail::QFlatMapMockPointer<U>;
+
 public:
     using key_type = Key;
     using mapped_type = T;