Add QString::compare(QStringView, CaseSensitivity)

There was a QStringView::compare(QString, CaseSensitivity) but it's
good that the symmetric also exists

Change-Id: Ic789f11d41eb8cfa393cb51c19bd1f89bb87d912
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/tools/qstring.cpp

@@ -6225,7 +6225,17 @@ QString& QString::fill(QChar ch, int size)
     sensitivity setting \a cs.
 */
 
+/*!
+    \fn int QString::compare(QStringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const
 
+    \since 5.12
+    \overload compare()
+
+    Performs a comparison of this with \a s, using the case
+    sensitivity setting \a cs.
+*/
+
+#if QT_STRINGVIEW_LEVEL < 2
 /*!
     \overload compare()
     \since 4.2
@@ -6241,6 +6251,7 @@ int QString::compare(const QString &other, Qt::CaseSensitivity cs) const Q_DECL_
 {
     return qt_compare_strings(*this, other, cs);
 }
+#endif
 
 /*!
     \internal
@@ -6267,6 +6278,7 @@ int QString::compare(QLatin1String other, Qt::CaseSensitivity cs) const Q_DECL_N
     return qt_compare_strings(*this, other, cs);
 }
 
+#if QT_STRINGVIEW_LEVEL < 2
 /*!
   \fn int QString::compare(const QStringRef &ref, Qt::CaseSensitivity cs = Qt::CaseSensitive) const
   \overload compare()
@@ -6275,6 +6287,7 @@ int QString::compare(QLatin1String other, Qt::CaseSensitivity cs) const Q_DECL_N
   an integer less than, equal to, or greater than zero if the string
   is less than, equal to, or greater than \a ref.
 */
+#endif
 
 /*!
     \internal

src/corelib/tools/qstring.h

@@ -608,8 +608,12 @@ public:
     QString &setUnicode(const QChar *unicode, int size);
     inline QString &setUtf16(const ushort *utf16, int size);
 
+#if QT_STRINGVIEW_LEVEL < 2
     int compare(const QString &s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const Q_DECL_NOTHROW;
+    inline int compare(const QStringRef &s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const Q_DECL_NOTHROW;
+#endif
     int compare(QLatin1String other, Qt::CaseSensitivity cs = Qt::CaseSensitive) const Q_DECL_NOTHROW;
+    inline int compare(QStringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const Q_DECL_NOTHROW;
 
     static inline int compare(const QString &s1, const QString &s2,
                               Qt::CaseSensitivity cs = Qt::CaseSensitive) Q_DECL_NOTHROW
@@ -622,7 +626,6 @@ public:
                               Qt::CaseSensitivity cs = Qt::CaseSensitive) Q_DECL_NOTHROW
     { return -s2.compare(s1, cs); }
 
-    inline int compare(const QStringRef &s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const Q_DECL_NOTHROW;
     static int compare(const QString &s1, const QStringRef &s2,
                        Qt::CaseSensitivity = Qt::CaseSensitive) Q_DECL_NOTHROW;
 
@@ -1638,8 +1641,12 @@ inline bool operator> (const QStringRef &lhs, const QString &rhs) Q_DECL_NOTHROW
 inline bool operator<=(const QStringRef &lhs, const QString &rhs) Q_DECL_NOTHROW { return rhs >= lhs; }
 inline bool operator>=(const QStringRef &lhs, const QString &rhs) Q_DECL_NOTHROW { return rhs <= lhs; }
 
+#if QT_STRINGVIEW_LEVEL < 2
 inline int QString::compare(const QStringRef &s, Qt::CaseSensitivity cs) const Q_DECL_NOTHROW
 { return QString::compare_helper(constData(), length(), s.constData(), s.length(), cs); }
+#endif
+inline int QString::compare(QStringView s, Qt::CaseSensitivity cs) const Q_DECL_NOTHROW
+{ return -s.compare(*this, cs); }
 inline int QString::compare(const QString &s1, const QStringRef &s2, Qt::CaseSensitivity cs) Q_DECL_NOTHROW
 { return QString::compare_helper(s1.constData(), s1.length(), s2.constData(), s2.length(), cs); }
 inline int QStringRef::compare(const QString &s, Qt::CaseSensitivity cs) const Q_DECL_NOTHROW

tests/auto/corelib/tools/qstring/tst_qstring.cpp

@@ -6238,11 +6238,14 @@ void tst_QString::compare()
     QStringRef r1(&s1, 0, s1.length());
     QStringRef r2(&s2, 0, s2.length());
 
+    const QStringView v2(s2);
+
     QCOMPARE(sign(QString::compare(s1, s2)), csr);
     QCOMPARE(sign(QStringRef::compare(r1, r2)), csr);
     QCOMPARE(sign(s1.compare(s2)), csr);
     QCOMPARE(sign(s1.compare(r2)), csr);
     QCOMPARE(sign(r1.compare(r2)), csr);
+    QCOMPARE(sign(s1.compare(v2)), csr);
 
     QCOMPARE(sign(s1.compare(s2, Qt::CaseSensitive)), csr);
     QCOMPARE(sign(s1.compare(s2, Qt::CaseInsensitive)), cir);
@@ -6250,6 +6253,8 @@ void tst_QString::compare()
     QCOMPARE(sign(s1.compare(r2, Qt::CaseInsensitive)), cir);
     QCOMPARE(sign(r1.compare(r2, Qt::CaseSensitive)), csr);
     QCOMPARE(sign(r1.compare(r2, Qt::CaseInsensitive)), cir);
+    QCOMPARE(sign(s1.compare(v2, Qt::CaseSensitive)), csr);
+    QCOMPARE(sign(s1.compare(v2, Qt::CaseInsensitive)), cir);
 
     QCOMPARE(sign(QString::compare(s1, s2, Qt::CaseSensitive)), csr);
     QCOMPARE(sign(QString::compare(s1, s2, Qt::CaseInsensitive)), cir);