From 3afcfbc400526d84a434b7efb03d3854f6992ef6 Mon Sep 17 00:00:00 2001
From: Marc Mutz <marc.mutz@qt.io>
Date: Wed, 24 Jan 2024 10:15:28 +0100
Subject: [PATCH] Port QVersionNumber to QSpan

The new ctor could replace all existing ones. However, keep the QList
ctors to participate in implicit sharing, but mark them as weak
overloads in order to break the ambiguity for arguments that convert
to both QList and QSpan. Also keep the initalizer_list ctor because
it's implicit, and should be.

[ChangeLog][Potentially Source-Incompatible Changes] We have begun to
port APIs to QSpan, replacing overload sets of concrete container
classes. This breaks code that relied on concrete container class
overloads and passed types that implicitly convert to such a
container, but not to QSpan. The backwards-compatible fix is to make
the conversion explicit.

[ChangeLog][QtCore][QVersionNumber] Added construction from QSpan,
replacing the QVarLengthArray constructor.

Fixes: QTBUG-121480
Change-Id: I9be173d0471872ddc449c876465c6a01abc49ff4
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
---
 src/corelib/tools/qversionnumber.cpp |  9 ++++++---
 src/corelib/tools/qversionnumber.h   | 12 +++++++-----
 2 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/src/corelib/tools/qversionnumber.cpp b/src/corelib/tools/qversionnumber.cpp
index 84bce0cfd41..4b8ace71cc9 100644
--- a/src/corelib/tools/qversionnumber.cpp
+++ b/src/corelib/tools/qversionnumber.cpp
@@ -81,10 +81,13 @@ QT_IMPL_METATYPE_EXTERN(QVersionNumber)
 */
 
 /*!
-    \fn template <qsizetype N> QVersionNumber::QVersionNumber(const QVarLengthArray<int, N> &seg)
-    \since 6.4
+    \fn QVersionNumber::QVersionNumber(QSpan<const int> args)
+    \since 6.8
 
-    Constructs a version number from the list of numbers contained in \a seg.
+    Constructs a version number from the span specified by \a args.
+
+    \note In Qt versions prior to 6.8, QVersionNumber could only be constructed
+    from QList, QVarLenthArray or std::initializer_list.
 */
 
 /*!
diff --git a/src/corelib/tools/qversionnumber.h b/src/corelib/tools/qversionnumber.h
index 80cf7428c90..95217a6effa 100644
--- a/src/corelib/tools/qversionnumber.h
+++ b/src/corelib/tools/qversionnumber.h
@@ -10,6 +10,7 @@
 #include <QtCore/qlist.h>
 #include <QtCore/qmetatype.h>
 #include <QtCore/qnamespace.h>
+#include <QtCore/qspan.h>
 #include <QtCore/qstring.h>
 #include <QtCore/qtypeinfo.h>
 #if !defined(QT_LEAN_HEADERS) || QT_LEAN_HEADERS < 2
@@ -113,7 +114,7 @@ class QVersionNumber
 
         Q_CORE_EXPORT void setListData(QList<int> &&seg);
 
-        explicit SegmentStorage(std::initializer_list<int> args)
+        explicit SegmentStorage(QSpan<const int> args)
             : SegmentStorage(args.begin(), args.end()) {}
 
         explicit SegmentStorage(const int *first, const int *last)
@@ -256,19 +257,20 @@ public:
     inline QVersionNumber() noexcept
         : m_segments()
     {}
+    Q_WEAK_OVERLOAD
     inline explicit QVersionNumber(const QList<int> &seg) : m_segments(seg) { }
 
     // compiler-generated copy/move ctor/assignment operators and the destructor are ok
 
+    Q_WEAK_OVERLOAD
     explicit QVersionNumber(QList<int> &&seg) : m_segments(std::move(seg)) { }
 
     inline QVersionNumber(std::initializer_list<int> args)
-        : m_segments(args)
+        : m_segments(QSpan{args})
     {}
 
-    template <qsizetype N>
-    explicit QVersionNumber(const QVarLengthArray<int, N> &sec)
-        : m_segments(sec.begin(), sec.end())
+    explicit QVersionNumber(QSpan<const int> args)
+        : m_segments(args)
     {}
 
     inline explicit QVersionNumber(int maj)