From 3afd06cd43d78ef0992eaa6a458572eea6769297 Mon Sep 17 00:00:00 2001
From: Allan Sandfeld Jensen <allan.jensen@qt.io>
Date: Thu, 29 Oct 2020 14:30:50 +0100
Subject: [PATCH] Hide QList comparisons from ADL

Makes them member methods instead of hidden inline, as those actually
gets listed in documentation, and two were already documented as such.

Task-number: QTBUG-87975
Change-Id: I382ff8b701753f1fe150a38f4c530a52c98ad292
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
---
 src/corelib/tools/qlist.h    | 110 +++++++++++++++--------------------
 src/corelib/tools/qlist.qdoc |  28 ++++-----
 2 files changed, 60 insertions(+), 78 deletions(-)

diff --git a/src/corelib/tools/qlist.h b/src/corelib/tools/qlist.h
index 58676eeb1f..96efe28a31 100644
--- a/src/corelib/tools/qlist.h
+++ b/src/corelib/tools/qlist.h
@@ -204,18 +204,56 @@ public:
 
     // compiler-generated special member functions are fine!
 
-#ifdef Q_QDOC
-    // extra missing ones:
-    bool operator==(const QList<T> &other) const;
-    bool operator!=(const QList<T> &other) const;
-#endif
-
     void swap(QList<T> &other) noexcept { qSwap(d, other.d); }
 
-    template <typename U>
-    friend QTypeTraits::compare_eq_result<U> operator==(const QList<U> &l, const QList<U> &r);
-    template <typename U>
-    friend QTypeTraits::compare_eq_result<U> operator!=(const QList<U> &l, const QList<U> &r);
+    template <typename U = T>
+    QTypeTraits::compare_eq_result<U> operator==(const QList &other) const
+    {
+        if (size() != other.size())
+            return false;
+        if (begin() == other.begin())
+            return true;
+
+        // do element-by-element comparison
+        return d->compare(begin(), other.begin(), size());
+    }
+    template <typename U = T>
+    QTypeTraits::compare_eq_result<U> operator!=(const QList &other) const
+    {
+        return !(*this == other);
+    }
+
+    template <typename U = T>
+    QTypeTraits::compare_lt_result<U> operator<(const QList &other) const
+        noexcept(noexcept(std::lexicographical_compare<typename QList<U>::const_iterator,
+                                                       typename QList::const_iterator>(
+                            std::declval<QList<U>>().begin(), std::declval<QList<U>>().end(),
+                            other.begin(), other.end())))
+    {
+        return std::lexicographical_compare(begin(), end(),
+                                            other.begin(), other.end());
+    }
+
+    template <typename U = T>
+    QTypeTraits::compare_lt_result<U> operator>(const QList &other) const
+        noexcept(noexcept(other < std::declval<QList<U>>()))
+    {
+        return other < *this;
+    }
+
+    template <typename U = T>
+    QTypeTraits::compare_lt_result<U> operator<=(const QList &other) const
+        noexcept(noexcept(other < std::declval<QList<U>>()))
+    {
+        return !(other < *this);
+    }
+
+    template <typename U = T>
+    QTypeTraits::compare_lt_result<U> operator>=(const QList &other) const
+        noexcept(noexcept(std::declval<QList<U>>() < other))
+    {
+        return !(*this < other);
+    }
 
     qsizetype size() const noexcept { return d->size; }
     qsizetype count() const noexcept { return size(); }
@@ -856,58 +894,6 @@ size_t qHash(const QList<T> &key, size_t seed = 0)
     return qHashRange(key.cbegin(), key.cend(), seed);
 }
 
-template <typename U>
-QTypeTraits::compare_eq_result<U> operator==(const QList<U> &l, const QList<U> &r)
-{
-    if (l.size() != r.size())
-        return false;
-    if (l.begin() == r.begin())
-        return true;
-
-    // do element-by-element comparison
-    return l.d->compare(l.begin(), r.begin(), l.size());
-}
-
-template <typename U>
-QTypeTraits::compare_eq_result<U> operator!=(const QList<U> &l, const QList<U> &r)
-{
-    return !(l == r);
-}
-
-template <typename T>
-auto operator<(const QList<T> &lhs, const QList<T> &rhs)
-    noexcept(noexcept(std::lexicographical_compare(lhs.begin(), lhs.end(),
-                                                   rhs.begin(), rhs.end())))
-    -> decltype(std::declval<T>() < std::declval<T>())
-{
-    return std::lexicographical_compare(lhs.begin(), lhs.end(),
-                                        rhs.begin(), rhs.end());
-}
-
-template <typename T>
-auto operator>(const QList<T> &lhs, const QList<T> &rhs)
-    noexcept(noexcept(lhs < rhs))
-    -> decltype(lhs < rhs)
-{
-    return rhs < lhs;
-}
-
-template <typename T>
-auto operator<=(const QList<T> &lhs, const QList<T> &rhs)
-    noexcept(noexcept(lhs < rhs))
-    -> decltype(lhs < rhs)
-{
-    return !(lhs > rhs);
-}
-
-template <typename T>
-auto operator>=(const QList<T> &lhs, const QList<T> &rhs)
-    noexcept(noexcept(lhs < rhs))
-    -> decltype(lhs < rhs)
-{
-    return !(lhs < rhs);
-}
-
 QList<uint> QStringView::toUcs4() const { return QtPrivate::convertToUcs4(*this); }
 
 QT_END_NAMESPACE
diff --git a/src/corelib/tools/qlist.qdoc b/src/corelib/tools/qlist.qdoc
index abfbd23d91..591be76018 100644
--- a/src/corelib/tools/qlist.qdoc
+++ b/src/corelib/tools/qlist.qdoc
@@ -388,49 +388,45 @@
     \sa operator==()
 */
 
-/*! \fn template <typename T> bool operator<(const QList<T> &lhs, const QList<T> &rhs)
+/*! \fn template <typename T> bool QList<T>::operator<(const QList<T> &other) const
     \since 5.6
-    \relates QList
 
-    Returns \c true if list \a lhs is
+    Returns \c true if this list is
     \l{http://en.cppreference.com/w/cpp/algorithm/lexicographical_compare}
-    {lexicographically less than} \a rhs; otherwise returns \c false.
+    {lexicographically less than} \a other; otherwise returns \c false.
 
     This function requires the value type to have an implementation
     of \c operator<().
 */
 
-/*! \fn template <typename T> bool operator<=(const QList<T> &lhs, const QList<T> &rhs)
+/*! \fn template <typename T> bool QList<T>::operator<=(const QList<T> &other) const
     \since 5.6
-    \relates QList
 
-    Returns \c true if list \a lhs is
+    Returns \c true if this list is
     \l{http://en.cppreference.com/w/cpp/algorithm/lexicographical_compare}
-    {lexicographically less than or equal to} \a rhs; otherwise returns \c false.
+    {lexicographically less than or equal to} \a other; otherwise returns \c false.
 
     This function requires the value type to have an implementation
     of \c operator<().
 */
 
-/*! \fn template <typename T> bool operator>(const QList<T> &lhs, const QList<T> &rhs)
+/*! \fn template <typename T> bool QList<T>::operator>(const QList<T> &other)
     \since 5.6
-    \relates QList
 
-    Returns \c true if list \a lhs is
+    Returns \c true if this list is
     \l{http://en.cppreference.com/w/cpp/algorithm/lexicographical_compare}
-    {lexicographically greater than} \a rhs; otherwise returns \c false.
+    {lexicographically greater than} \a other; otherwise returns \c false.
 
     This function requires the value type to have an implementation
     of \c operator<().
 */
 
-/*! \fn template <typename T> bool operator>=(const QList<T> &lhs, const QList<T> &rhs)
+/*! \fn template <typename T> bool QList<T>::operator>=(const QList<T> &other)
     \since 5.6
-    \relates QList
 
-    Returns \c true if list \a lhs is
+    Returns \c true if this list is
     \l{http://en.cppreference.com/w/cpp/algorithm/lexicographical_compare}
-    {lexicographically greater than or equal to} \a rhs; otherwise returns \c false.
+    {lexicographically greater than or equal to} \a other; otherwise returns \c false.
 
     This function requires the value type to have an implementation
     of \c operator<().