QStringView: Add compare() member function

There was no public API for doing case-insensitive comparisons
of QStringView.

Task-number: QTBUG-69389
Change-Id: I1b021eefec35e135b97fb87704c8dc137232d83d
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

3 files changed, 37 insertions, 0 deletions

diff --git a/src/corelib/tools/qstringview.cpp b/src/corelib/tools/qstringview.cpp
index 0e3246c72c..ce8fdacafb 100644
--- a/src/corelib/tools/qstringview.cpp
+++ b/src/corelib/tools/qstringview.cpp
@@ -681,6 +681,20 @@ QT_BEGIN_NAMESPACE
 */
 
 /*!
+    \fn int QStringView::compare(QStringView other, Qt::CaseSensitivity cs) const
+    \since 5.12
+
+    Compares this string-view with the \a other string-view and returns an
+    integer less than, equal to, or greater than zero if this string-view
+    is less than, equal to, or greater than the other string-view.
+
+    If \a cs is Qt::CaseSensitive, the comparison is case sensitive;
+    otherwise the comparison is case insensitive.
+
+    \sa operator==(), operator<(), operator>()
+*/
+
+/*!
     \fn bool QStringView::startsWith(QStringView str, Qt::CaseSensitivity cs) const
     \fn bool QStringView::startsWith(QLatin1String l1, Qt::CaseSensitivity cs) const
     \fn bool QStringView::startsWith(QChar ch) const
diff --git a/src/corelib/tools/qstringview.h b/src/corelib/tools/qstringview.h
index 4f7d48fe1d..2e95c2b218 100644
--- a/src/corelib/tools/qstringview.h
+++ b/src/corelib/tools/qstringview.h
@@ -250,6 +250,9 @@ public:
 
     Q_REQUIRED_RESULT QStringView trimmed() const Q_DECL_NOTHROW { return QtPrivate::trimmed(*this); }
 
+    Q_REQUIRED_RESULT int compare(QStringView other, Qt::CaseSensitivity cs = Qt::CaseSensitive) const Q_DECL_NOTHROW
+    { return QtPrivate::compareStrings(*this, other, cs); }
+
     Q_REQUIRED_RESULT bool startsWith(QStringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const Q_DECL_NOTHROW
     { return QtPrivate::startsWith(*this, s, cs); }
     Q_REQUIRED_RESULT inline bool startsWith(QLatin1String s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const Q_DECL_NOTHROW;
diff --git a/tests/auto/corelib/tools/qstringview/tst_qstringview.cpp b/tests/auto/corelib/tools/qstringview/tst_qstringview.cpp
index 4ae96005d0..e800a0d794 100644
--- a/tests/auto/corelib/tools/qstringview/tst_qstringview.cpp
+++ b/tests/auto/corelib/tools/qstringview/tst_qstringview.cpp
@@ -217,6 +217,8 @@ private Q_SLOTS:
 #endif
     }
 
+    void comparison();
+
 private:
     template <typename String>
     void conversion_tests(String arg) const;
@@ -615,5 +617,23 @@ void tst_QStringView::conversion_tests(String string) const
     }
 }
 
+void tst_QStringView::comparison()
+{
+    const QStringView aa = QStringViewLiteral("aa");
+    const QStringView upperAa = QStringViewLiteral("AA");
+    const QStringView bb = QStringViewLiteral("bb");
+
+    QVERIFY(aa == aa);
+    QVERIFY(aa != bb);
+    QVERIFY(aa < bb);
+    QVERIFY(bb > aa);
+
+    QCOMPARE(aa.compare(aa), 0);
+    QVERIFY(aa.compare(upperAa) != 0);
+    QCOMPARE(aa.compare(upperAa, Qt::CaseInsensitive), 0);
+    QVERIFY(aa.compare(bb) < 0);
+    QVERIFY(bb.compare(aa) > 0);
+}
+
 QTEST_APPLESS_MAIN(tst_QStringView)
 #include "tst_qstringview.moc"