1 files changed, 22 insertions, 15 deletions

diff --git a/src/corelib/tools/qset.h b/src/corelib/tools/qset.h
index 2a945a31e8..7330b5e91c 100644
--- a/src/corelib/tools/qset.h
+++ b/src/corelib/tools/qset.h
@@ -35,7 +35,7 @@ public:
 
     inline void swap(QSet<T> &other) noexcept { q_hash.swap(other.q_hash); }
 
-#ifndef Q_CLANG_QDOC
+#ifndef Q_QDOC
     template <typename U = T>
     QTypeTraits::compare_eq_result_container<QSet, U> operator==(const QSet<T> &other) const
     { return q_hash == other.q_hash; }
@@ -151,7 +151,7 @@ public:
     // more Qt
     typedef iterator Iterator;
     typedef const_iterator ConstIterator;
-    inline qsizetype count() const { return q_hash.count(); }
+    inline qsizetype count() const { return q_hash.size(); }
     inline iterator insert(const T &value)
         { return q_hash.insert(value, QHashDummyValue()); }
     inline iterator insert(T &&value)
@@ -189,14 +189,18 @@ public:
     inline QSet<T> &operator+=(const T &value) { insert(value); return *this; }
     inline QSet<T> &operator-=(const QSet<T> &other) { subtract(other); return *this; }
     inline QSet<T> &operator-=(const T &value) { remove(value); return *this; }
-    inline QSet<T> operator|(const QSet<T> &other) const
-        { QSet<T> result = *this; result |= other; return result; }
-    inline QSet<T> operator&(const QSet<T> &other) const
-        { QSet<T> result = *this; result &= other; return result; }
-    inline QSet<T> operator+(const QSet<T> &other) const
-        { QSet<T> result = *this; result += other; return result; }
-    inline QSet<T> operator-(const QSet<T> &other) const
-        { QSet<T> result = *this; result -= other; return result; }
+
+    friend QSet operator|(const QSet &lhs, const QSet &rhs) { return QSet(lhs) |= rhs; }
+    friend QSet operator|(QSet &&lhs, const QSet &rhs) { lhs |= rhs; return std::move(lhs); }
+
+    friend QSet operator&(const QSet &lhs, const QSet &rhs) { return QSet(lhs) &= rhs; }
+    friend QSet operator&(QSet &&lhs, const QSet &rhs) { lhs &= rhs; return std::move(lhs); }
+
+    friend QSet operator+(const QSet &lhs, const QSet &rhs) { return QSet(lhs) += rhs; }
+    friend QSet operator+(QSet &&lhs, const QSet &rhs) { lhs += rhs; return std::move(lhs); }
+
+    friend QSet operator-(const QSet &lhs, const QSet &rhs) { return QSet(lhs) -= rhs; }
+    friend QSet operator-(QSet &&lhs, const QSet &rhs) { lhs -= rhs; return std::move(lhs); }
 
     QList<T> values() const;
 
@@ -224,10 +228,13 @@ Q_INLINE_TEMPLATE void QSet<T>::reserve(qsizetype asize) { q_hash.reserve(asize)
 template <class T>
 Q_INLINE_TEMPLATE QSet<T> &QSet<T>::unite(const QSet<T> &other)
 {
-    if (!q_hash.isSharedWith(other.q_hash)) {
-        for (const T &e : other)
-            insert(e);
-    }
+    if (q_hash.isSharedWith(other.q_hash))
+        return *this;
+    QSet<T> tmp = other;
+    if (size() < other.size())
+        swap(tmp);
+    for (const auto &e : std::as_const(tmp))
+        insert(e);
     return *this;
 }
 
@@ -244,7 +251,7 @@ Q_INLINE_TEMPLATE QSet<T> &QSet<T>::intersect(const QSet<T> &other)
         copy2 = *this;
         *this = copy1;
     }
-    for (const auto &e : qAsConst(copy1)) {
+    for (const auto &e : std::as_const(copy1)) {
         if (!copy2.contains(e))
             remove(e);
     }