QSet: add missing insert-with-hint

Since QHash is missing the overload, too, just ignore the hint for
now, but provide the STL-compatible signature so generic code can use
QSet as a normal sequential container.

[ChangeLog][QtCore][QSet] Added insert() overload taking an insertion
hint, for STL compatibility.

Change-Id: I9fe41877343ebff721b650fb7b9cd4e06b6608d8
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Andrei Golubev <andrei.golubev@qt.io>

src/corelib/tools/qset.h

@@ -198,6 +198,9 @@ public:
     typedef qsizetype size_type;
 
     inline bool empty() const { return isEmpty(); }
+
+    iterator insert(const_iterator, const T &value) { return insert(value); }
+
     // comfort
     inline QSet<T> &operator<<(const T &value) { insert(value); return *this; }
     inline QSet<T> &operator|=(const QSet<T> &other) { unite(other); return *this; }

src/corelib/tools/qset.qdoc

@@ -507,6 +507,22 @@
     for STL compatibility. It is equivalent to isEmpty().
 */
 
+/*!
+    \fn QSet::insert(const_iterator it, const T &value)
+    \overload
+    \since 6.1
+
+    Inserts item \a value into the set, if \a value isn't already
+    in the set, and returns an iterator pointing at the inserted
+    item.
+
+    The iterator \a it is ignored.
+
+    This function is provided for compatibility with the STL.
+
+    \sa operator<<(), remove(), contains()
+*/
+
 /*!
     \fn template <class T> bool QSet<T>::count() const
 

tests/auto/corelib/kernel/qmetacontainer/tst_qmetacontainer.cpp

@@ -143,7 +143,7 @@ static_assert(!QContainerInfo::can_set_value_at_iterator_v<std::set<int>>);
 static_assert(QContainerInfo::can_set_value_at_iterator_v<std::forward_list<int>>);
 
 static_assert(QContainerInfo::can_insert_value_at_iterator_v<QVector<int>>);
-static_assert(!QContainerInfo::can_insert_value_at_iterator_v<QSet<int>>);
+static_assert(QContainerInfo::can_insert_value_at_iterator_v<QSet<int>>);
 static_assert(!QContainerInfo::can_insert_value_at_iterator_v<NotAContainer>);
 static_assert(QContainerInfo::can_insert_value_at_iterator_v<std::vector<int>>);
 static_assert(!QContainerInfo::can_insert_value_at_iterator_v<std::forward_list<int>>);
@@ -267,7 +267,7 @@ void tst_QMetaContainer::testSequence_data()
             << static_cast<void *>(&qset)
             << QMetaSequence::fromContainer<QSet<QByteArray>>()
             << QMetaType::fromType<QByteArray>()
-            << true << false << false << false << false << false << true << false;
+            << true << false << false << false << false << true << true << false;
     QTest::addRow("std::set")
             << static_cast<void *>(&stdset)
             << QMetaSequence::fromContainer<std::set<int>>()