Replace qExchange calls with std::exchange

qExchange is one of the few remaining functionalities that have not been
moved out of qglobal. Given that std::exchange exists in the standard, we
can simply move to it everywhere...

...if it weren't for the fact that std::exchange is only constexpr in
C++20, and only has its noexceptness specified in (most likely) C++23.
Still, we want to move to the existing std functionality where
possible, to allow the removal of qglobal includes in lieu of something
more fine-grained in the future.
So leave any constexpr calls[1] alone for now (and observe that none of
our current usages cares about the conditional noexceptness), but
replace everything else.

[1] QScopedValueRollback' ctor and QExplicitlySharedDataPointerV2::take

Task-number: QTBUG-99313
Change-Id: I599cb9846cf319c7ffd3457130938347a75aad25
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

15 files changed, 23 insertions, 23 deletions

diff --git a/src/corelib/io/qdebug.h b/src/corelib/io/qdebug.h
index b7cdd67568..f8fd877010 100644
--- a/src/corelib/io/qdebug.h
+++ b/src/corelib/io/qdebug.h
@@ -72,7 +72,7 @@ public:
     explicit QDebug(QString *string) : stream(new Stream(string)) {}
     explicit QDebug(QtMsgType t) : stream(new Stream(t)) {}
     QDebug(const QDebug &o) : stream(o.stream) { ++stream->ref; }
-    QDebug(QDebug &&other) noexcept : stream{qExchange(other.stream, nullptr)} {}
+    QDebug(QDebug &&other) noexcept : stream{std::exchange(other.stream, nullptr)} {}
     inline QDebug &operator=(const QDebug &other);
     QT_MOVE_ASSIGNMENT_OPERATOR_IMPL_VIA_MOVE_AND_SWAP(QDebug)
     ~QDebug();
diff --git a/src/corelib/itemmodels/qabstractitemmodel.h b/src/corelib/itemmodels/qabstractitemmodel.h
index dbeb237797..e56412241a 100644
--- a/src/corelib/itemmodels/qabstractitemmodel.h
+++ b/src/corelib/itemmodels/qabstractitemmodel.h
@@ -184,7 +184,7 @@ public:
     { return !operator==(other); }
     QPersistentModelIndex &operator=(const QPersistentModelIndex &other);
     inline QPersistentModelIndex(QPersistentModelIndex &&other) noexcept
-        : d(qExchange(other.d, nullptr)) {}
+        : d(std::exchange(other.d, nullptr)) {}
     QT_MOVE_ASSIGNMENT_OPERATOR_IMPL_VIA_PURE_SWAP(QPersistentModelIndex)
     void swap(QPersistentModelIndex &other) noexcept { qt_ptr_swap(d, other.d); }
     bool operator==(const QModelIndex &other) const;
diff --git a/src/corelib/kernel/qbasictimer.h b/src/corelib/kernel/qbasictimer.h
index 13d48822f5..b39a78d293 100644
--- a/src/corelib/kernel/qbasictimer.h
+++ b/src/corelib/kernel/qbasictimer.h
@@ -22,7 +22,7 @@ public:
     inline ~QBasicTimer() { if (id) stop(); }
 
     QBasicTimer(QBasicTimer &&other) noexcept
-        : id{qExchange(other.id, 0)}
+        : id{std::exchange(other.id, 0)}
     {}
 
     QT_MOVE_ASSIGNMENT_OPERATOR_IMPL_VIA_MOVE_AND_SWAP(QBasicTimer)
diff --git a/src/corelib/kernel/qobjectdefs.h b/src/corelib/kernel/qobjectdefs.h
index 458860209b..845e44882d 100644
--- a/src/corelib/kernel/qobjectdefs.h
+++ b/src/corelib/kernel/qobjectdefs.h
@@ -600,7 +600,7 @@ public:
     operator RestrictedBool() const { return d_ptr && isConnected_helper() ? &Connection::d_ptr : nullptr; }
 #endif
 
-    Connection(Connection &&other) noexcept : d_ptr(qExchange(other.d_ptr, nullptr)) {}
+    Connection(Connection &&other) noexcept : d_ptr(std::exchange(other.d_ptr, nullptr)) {}
     QT_MOVE_ASSIGNMENT_OPERATOR_IMPL_VIA_PURE_SWAP(Connection)
     void swap(Connection &other) noexcept { qt_ptr_swap(d_ptr, other.d_ptr); }
 };
diff --git a/src/corelib/kernel/qproperty.cpp b/src/corelib/kernel/qproperty.cpp
index a6435830f9..37c5b8d013 100644
--- a/src/corelib/kernel/qproperty.cpp
+++ b/src/corelib/kernel/qproperty.cpp
@@ -25,7 +25,7 @@ void QPropertyBindingPrivatePtr::reset(QtPrivate::RefCounted *ptr) noexcept
     if (ptr != d) {
         if (ptr)
             ptr->ref++;
-        auto *old = qExchange(d, ptr);
+        auto *old = std::exchange(d, ptr);
         if (old && (--old->ref == 0))
             QPropertyBindingPrivate::destroyAndFreeMemory(static_cast<QPropertyBindingPrivate *>(d));
     }
diff --git a/src/corelib/kernel/qpropertyprivate.h b/src/corelib/kernel/qpropertyprivate.h
index 1356a3702e..966821fa67 100644
--- a/src/corelib/kernel/qpropertyprivate.h
+++ b/src/corelib/kernel/qpropertyprivate.h
@@ -82,7 +82,7 @@ public:
         reset(o);
         return *this;
     }
-    QPropertyBindingPrivatePtr(QPropertyBindingPrivatePtr &&o) noexcept : d(qExchange(o.d, nullptr)) {}
+    QPropertyBindingPrivatePtr(QPropertyBindingPrivatePtr &&o) noexcept : d(std::exchange(o.d, nullptr)) {}
     QT_MOVE_ASSIGNMENT_OPERATOR_IMPL_VIA_MOVE_AND_SWAP(QPropertyBindingPrivatePtr)
 
     operator bool () const noexcept { return d != nullptr; }
diff --git a/src/corelib/plugin/qfactoryloader.cpp b/src/corelib/plugin/qfactoryloader.cpp
index 4ee87d0dab..06015127d6 100644
--- a/src/corelib/plugin/qfactoryloader.cpp
+++ b/src/corelib/plugin/qfactoryloader.cpp
@@ -319,7 +319,7 @@ void QFactoryLoader::setExtraSearchPath(const QString &path)
         return;             // nothing to do
 
     QMutexLocker locker(&qt_factoryloader_global->mutex);
-    QString oldPath = qExchange(d->extraSearchPath, path);
+    QString oldPath = std::exchange(d->extraSearchPath, path);
     if (oldPath.isEmpty()) {
         // easy case, just update this directory
         d->updateSinglePath(d->extraSearchPath);
diff --git a/src/corelib/serialization/qcborvalue.h b/src/corelib/serialization/qcborvalue.h
index ff4a0fd104..b95d25d6fd 100644
--- a/src/corelib/serialization/qcborvalue.h
+++ b/src/corelib/serialization/qcborvalue.h
@@ -141,7 +141,7 @@ public:
 
     QCborValue(const QCborValue &other) noexcept;
     QCborValue(QCborValue &&other) noexcept
-        : n(other.n), container(qExchange(other.container, nullptr)), t(qExchange(other.t, Undefined))
+        : n(other.n), container(std::exchange(other.container, nullptr)), t(std::exchange(other.t, Undefined))
     {
     }
     QCborValue &operator=(const QCborValue &other) noexcept;
diff --git a/src/corelib/text/qregularexpression.cpp b/src/corelib/text/qregularexpression.cpp
index 866f3976af..0aa9087727 100644
--- a/src/corelib/text/qregularexpression.cpp
+++ b/src/corelib/text/qregularexpression.cpp
@@ -2671,7 +2671,7 @@ QRegularExpressionMatch QRegularExpressionMatchIterator::next()
     }
 
     d.detach();
-    return qExchange(d->next, d->next.d.constData()->nextMatch());
+    return std::exchange(d->next, d->next.d.constData()->nextMatch());
 }
 
 /*!
diff --git a/src/corelib/thread/qsemaphore.h b/src/corelib/thread/qsemaphore.h
index 3df0765902..8823468dbc 100644
--- a/src/corelib/thread/qsemaphore.h
+++ b/src/corelib/thread/qsemaphore.h
@@ -82,7 +82,7 @@ public:
 
     QSemaphore *cancel() noexcept
     {
-        return qExchange(m_sem, nullptr);
+        return std::exchange(m_sem, nullptr);
     }
 
 private:
diff --git a/src/corelib/tools/qhash.h b/src/corelib/tools/qhash.h
index 5075459531..9f06b5d36e 100644
--- a/src/corelib/tools/qhash.h
+++ b/src/corelib/tools/qhash.h
@@ -172,7 +172,7 @@ struct MultiNode
 
     MultiNode(MultiNode &&other)
         : key(other.key),
-          value(qExchange(other.value, nullptr))
+          value(std::exchange(other.value, nullptr))
     {
     }
 
@@ -203,7 +203,7 @@ struct MultiNode
     void insertMulti(Args &&... args)
     {
         Chain *e = new Chain{ T(std::forward<Args>(args)...), nullptr };
-        e->next = qExchange(value, e);
+        e->next = std::exchange(value, e);
     }
     template<typename ...Args>
     void emplaceValue(Args &&... args)
@@ -1412,8 +1412,8 @@ public:
         return *this;
     }
     QMultiHash(QMultiHash &&other) noexcept
-        : d(qExchange(other.d, nullptr)),
-          m_size(qExchange(other.m_size, 0))
+        : d(std::exchange(other.d, nullptr)),
+          m_size(std::exchange(other.m_size, 0))
     {
     }
     QMultiHash &operator=(QMultiHash &&other) noexcept(std::is_nothrow_destructible<Node>::value)
diff --git a/src/corelib/tools/qscopedpointer.h b/src/corelib/tools/qscopedpointer.h
index 1ad7acb0f4..1637bb40a5 100644
--- a/src/corelib/tools/qscopedpointer.h
+++ b/src/corelib/tools/qscopedpointer.h
@@ -120,7 +120,7 @@ public:
     {
         if (d == other)
             return;
-        T *oldD = qExchange(d, other);
+        T *oldD = std::exchange(d, other);
         Cleanup::cleanup(oldD);
     }
 
@@ -128,7 +128,7 @@ public:
     QT_DEPRECATED_VERSION_X_6_1("Use std::unique_ptr instead, and call release().")
     T *take() noexcept
     {
-        T *oldD = qExchange(d, nullptr);
+        T *oldD = std::exchange(d, nullptr);
         return oldD;
     }
 #endif
diff --git a/src/corelib/tools/qscopeguard.h b/src/corelib/tools/qscopeguard.h
index 2639b41222..5bd202ce33 100644
--- a/src/corelib/tools/qscopeguard.h
+++ b/src/corelib/tools/qscopeguard.h
@@ -28,7 +28,7 @@ public:
 
     QScopeGuard(QScopeGuard &&other) noexcept
         : m_func(std::move(other.m_func))
-        , m_invoke(qExchange(other.m_invoke, false))
+        , m_invoke(std::exchange(other.m_invoke, false))
     {
     }
 
diff --git a/src/corelib/tools/qshareddata.h b/src/corelib/tools/qshareddata.h
index be848e2ef8..813e9d6c7a 100644
--- a/src/corelib/tools/qshareddata.h
+++ b/src/corelib/tools/qshareddata.h
@@ -66,7 +66,7 @@ public:
         if (ptr != d) {
             if (ptr)
                 ptr->ref.ref();
-            T *old = qExchange(d, ptr);
+            T *old = std::exchange(d, ptr);
             if (old && !old->ref.deref())
                 delete old;
         }
@@ -82,7 +82,7 @@ public:
         reset(o);
         return *this;
     }
-    QSharedDataPointer(QSharedDataPointer &&o) noexcept : d(qExchange(o.d, nullptr)) {}
+    QSharedDataPointer(QSharedDataPointer &&o) noexcept : d(std::exchange(o.d, nullptr)) {}
     QT_MOVE_ASSIGNMENT_OPERATOR_IMPL_VIA_MOVE_AND_SWAP(QSharedDataPointer)
 
     operator bool () const noexcept { return d != nullptr; }
@@ -135,7 +135,7 @@ public:
     T *data() const noexcept { return d; }
     T *get() const noexcept { return d; }
     const T *constData() const noexcept { return d; }
-    T *take() noexcept { return qExchange(d, nullptr); }
+    T *take() noexcept { return std::exchange(d, nullptr); }
 
     void detach() { if (d && d->ref.loadRelaxed() != 1) detach_helper(); }
 
@@ -163,7 +163,7 @@ public:
         if (ptr != d) {
             if (ptr)
                 ptr->ref.ref();
-            T *old = qExchange(d, ptr);
+            T *old = std::exchange(d, ptr);
             if (old && !old->ref.deref())
                 delete old;
         }
@@ -179,7 +179,7 @@ public:
         reset(o);
         return *this;
     }
-    QExplicitlySharedDataPointer(QExplicitlySharedDataPointer &&o) noexcept : d(qExchange(o.d, nullptr)) {}
+    QExplicitlySharedDataPointer(QExplicitlySharedDataPointer &&o) noexcept : d(std::exchange(o.d, nullptr)) {}
     QT_MOVE_ASSIGNMENT_OPERATOR_IMPL_VIA_MOVE_AND_SWAP(QExplicitlySharedDataPointer)
 
     operator bool () const noexcept { return d != nullptr; }
diff --git a/src/corelib/tools/qshareddata_impl.h b/src/corelib/tools/qshareddata_impl.h
index 61a9d1d105..a0216397cc 100644
--- a/src/corelib/tools/qshareddata_impl.h
+++ b/src/corelib/tools/qshareddata_impl.h
@@ -51,7 +51,7 @@ public:
     }
 
     QExplicitlySharedDataPointerV2(QExplicitlySharedDataPointerV2 &&other) noexcept
-        : d(qExchange(other.d, nullptr))
+        : d(std::exchange(other.d, nullptr))
     {
     }