QLatin1String/QStringView: add (missing) member compare()

[ChangeLog][QtCore][QLatin1String] Added compare().

[ChangeLog][QtCore][QStringView] Added compare() overloads
taking QLatin1String, QChar.

Change-Id: Ie2aa400299cb63495e65ce29b2a32133066de826
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

4 files changed, 53 insertions, 6 deletions

diff --git a/src/corelib/text/qstring.cpp b/src/corelib/text/qstring.cpp
index f64f148f49..210a8afc53 100644
--- a/src/corelib/text/qstring.cpp
+++ b/src/corelib/text/qstring.cpp
@@ -9718,6 +9718,23 @@ QString &QString::setRawData(const QChar *unicode, int size)
 */
 
 /*!
+    \fn int QLatin1String::compare(QStringView str, Qt::CaseSensitivity cs) const
+    \fn int QLatin1String::compare(QLatin1String l1, Qt::CaseSensitivity cs) const
+    \fn int QLatin1String::compare(QChar ch) const
+    \fn int QLatin1String::compare(QChar ch, Qt::CaseSensitivity cs) const
+    \since 5.14
+
+    Returns an integer that compares to zero as this Latin-1 string compares to the
+    string-view \a str, Latin-1 string \a l1, or character \a ch, respectively.
+
+    If \a cs is Qt::CaseSensitive (the default), the comparison is case sensitive;
+    otherwise the comparison is case-insensitive.
+
+    \sa operator==(), operator<(), operator>()
+*/
+
+
+/*!
     \fn bool QLatin1String::startsWith(QStringView str, Qt::CaseSensitivity cs) const
     \since 5.10
     \fn bool QLatin1String::startsWith(QLatin1String l1, Qt::CaseSensitivity cs) const
diff --git a/src/corelib/text/qstring.h b/src/corelib/text/qstring.h
index d615e6646c..99b41c8ebf 100644
--- a/src/corelib/text/qstring.h
+++ b/src/corelib/text/qstring.h
@@ -111,6 +111,15 @@ public:
     Q_REQUIRED_RESULT Q_DECL_CONSTEXPR QLatin1Char front() const { return at(0); }
     Q_REQUIRED_RESULT Q_DECL_CONSTEXPR QLatin1Char back() const { return at(size() - 1); }
 
+    Q_REQUIRED_RESULT int compare(QStringView other, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
+    { return QtPrivate::compareStrings(*this, other, cs); }
+    Q_REQUIRED_RESULT int compare(QLatin1String other, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
+    { return QtPrivate::compareStrings(*this, other, cs); }
+    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR int compare(QChar c) const noexcept
+    { return isEmpty() || front() == c ? size() - 1 : uchar(m_data[0]) - c.unicode() ; }
+    Q_REQUIRED_RESULT int compare(QChar c, Qt::CaseSensitivity cs) const noexcept
+    { return QtPrivate::compareStrings(*this, QStringView(&c, 1), cs); }
+
     Q_REQUIRED_RESULT bool startsWith(QStringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
     { return QtPrivate::startsWith(*this, s, cs); }
     Q_REQUIRED_RESULT bool startsWith(QLatin1String s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
@@ -233,6 +242,8 @@ Q_DECL_CONSTEXPR bool QtPrivate::isLatin1(QLatin1String) noexcept
 //
 // QStringView members that require QLatin1String:
 //
+int QStringView::compare(QLatin1String s, Qt::CaseSensitivity cs) const noexcept
+{ return QtPrivate::compareStrings(*this, s, cs); }
 bool QStringView::startsWith(QLatin1String s, Qt::CaseSensitivity cs) const noexcept
 { return QtPrivate::startsWith(*this, s, cs); }
 bool QStringView::endsWith(QLatin1String s, Qt::CaseSensitivity cs) const noexcept
diff --git a/src/corelib/text/qstringview.cpp b/src/corelib/text/qstringview.cpp
index 08dade7e68..9df656dc59 100644
--- a/src/corelib/text/qstringview.cpp
+++ b/src/corelib/text/qstringview.cpp
@@ -692,15 +692,29 @@ QT_BEGIN_NAMESPACE
 */
 
 /*!
-    \fn int QStringView::compare(QStringView other, Qt::CaseSensitivity cs) const
+    \fn int QStringView::compare(QStringView str, 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.
+    Returns an integer that compares to zero as this string-view compares to the
+    string-view \a str.
 
-    If \a cs is Qt::CaseSensitive, the comparison is case sensitive;
-    otherwise the comparison is case insensitive.
+    If \a cs is Qt::CaseSensitive (the default), the comparison is case sensitive;
+    otherwise the comparison is case-insensitive.
+
+    \sa operator==(), operator<(), operator>()
+*/
+
+/*!
+    \fn int QStringView::compare(QLatin1String l1, Qt::CaseSensitivity cs) const
+    \fn int QStringView::compare(QChar ch) const
+    \fn int QStringView::compare(QChar ch, Qt::CaseSensitivity cs) const
+    \since 5.14
+
+    Returns an integer that compares to zero as this string-view compares to the
+    Latin-1 string \a l1, or character \a ch, respectively.
+
+    If \a cs is Qt::CaseSensitive (the default), the comparison is case sensitive;
+    otherwise the comparison is case-insensitive.
 
     \sa operator==(), operator<(), operator>()
 */
diff --git a/src/corelib/text/qstringview.h b/src/corelib/text/qstringview.h
index 06391ffef4..83418970a5 100644
--- a/src/corelib/text/qstringview.h
+++ b/src/corelib/text/qstringview.h
@@ -257,6 +257,11 @@ public:
 
     Q_REQUIRED_RESULT int compare(QStringView other, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
     { return QtPrivate::compareStrings(*this, other, cs); }
+    Q_REQUIRED_RESULT inline int compare(QLatin1String other, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept;
+    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR int compare(QChar c) const noexcept
+    { return empty() || front() == c ? size() - 1 : *utf16() - c.unicode() ; }
+    Q_REQUIRED_RESULT int compare(QChar c, Qt::CaseSensitivity cs) const noexcept
+    { return QtPrivate::compareStrings(*this, QStringView(&c, 1), cs); }
 
     Q_REQUIRED_RESULT bool startsWith(QStringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
     { return QtPrivate::startsWith(*this, s, cs); }