Turn QLocale's operator==() and operator!=() into hidden friends

Update docs to match. Add note on the conditions for equality.

Change-Id: I973b7a5dae3fae2e62f8a0d1db1f3115d24bee8b
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

3 files changed, 28 insertions, 15 deletions

diff --git a/src/corelib/text/qlocale.cpp b/src/corelib/text/qlocale.cpp
index 260af879db..1ac7742593 100644
--- a/src/corelib/text/qlocale.cpp
+++ b/src/corelib/text/qlocale.cpp
@@ -1060,14 +1060,14 @@ QLocale &QLocale::operator=(const QLocale &other)
     return *this;
 }
 
-bool QLocale::operator==(const QLocale &other) const
-{
-    return d->m_data == other.d->m_data && d->m_numberOptions == other.d->m_numberOptions;
-}
+/*!
+    \internal
+    Equality comparison.
+*/
 
-bool QLocale::operator!=(const QLocale &other) const
+bool QLocale::equals(const QLocale &other) const
 {
-    return d->m_data != other.d->m_data || d->m_numberOptions != other.d->m_numberOptions;
+    return d->m_data == other.d->m_data && d->m_numberOptions == other.d->m_numberOptions;
 }
 
 /*!
diff --git a/src/corelib/text/qlocale.h b/src/corelib/text/qlocale.h
index 269a8b8039..1ba0e3d79f 100644
--- a/src/corelib/text/qlocale.h
+++ b/src/corelib/text/qlocale.h
@@ -1028,9 +1028,6 @@ public:
 
     QStringList uiLanguages() const;
 
-    bool operator==(const QLocale &other) const;
-    bool operator!=(const QLocale &other) const;
-
     static QString languageToString(Language language);
     static QString countryToString(Country country);
     static QString scriptToString(Script script);
@@ -1054,12 +1051,16 @@ public:
 
 private:
     QLocale(QLocalePrivate &dd);
+    bool equals(const QLocale &other) const;
     friend class QLocalePrivate;
     friend class QSystemLocale;
     friend class QCalendarBackend;
     friend class QGregorianCalendar;
     friend Q_CORE_EXPORT size_t qHash(const QLocale &key, size_t seed) noexcept;
 
+    friend bool operator==(const QLocale &lhs, const QLocale &rhs) { return lhs.equals(rhs); }
+    friend bool operator!=(const QLocale &lhs, const QLocale &rhs) { return !lhs.equals(rhs); }
+
     QSharedDataPointer<QLocalePrivate> d;
 };
 Q_DECLARE_SHARED(QLocale)
diff --git a/src/corelib/text/qlocale.qdoc b/src/corelib/text/qlocale.qdoc
index 30c5ec6493..42f2e85264 100644
--- a/src/corelib/text/qlocale.qdoc
+++ b/src/corelib/text/qlocale.qdoc
@@ -979,17 +979,29 @@
 
 
 /*!
-    \fn bool QLocale::operator==(const QLocale &other) const
+    \fn bool QLocale::operator==(const QLocale &lhs, const QLocale &rhs)
 
-    Returns \c true if the QLocale object is the same as the \a other
-    locale specified; otherwise returns \c false.
+    Returns \c true if the two QLocale objects, \a lhs and \a rhs, are the same;
+    otherwise returns \c false.
+
+    \note The system locale is not equal to the QLocale object constructed from
+    its language(), script() and country(), even if the two agree in all data
+    fields. Nor are two locales with different number options equal.
+
+    \sa operator!=(), setNumberOptions()
 */
 
 /*!
-    \fn bool QLocale::operator!=(const QLocale &other) const
+    \fn bool QLocale::operator!=(const QLocale &lhs, const QLocale &rhs)
+
+    Returns \c true if the two QLocale objects, \a lhs and \a rhs, differ;
+    otherwise returns \c false.
+
+    \note The system locale is not equal to the QLocale object constructed from
+    its language(), script() and country(), even if the two agree in all data
+    fields. Nor are two locales with different number options equal.
 
-    Returns \c true if the QLocale object is not the same as the \a other
-    locale specified; otherwise returns \c false.
+    \sa operator==(), setNumberOptions()
 */
 
 /*!