QString: inline indexOf() and use a QChar overload

This is a repeat of the last commit, which did the same for QByteArray.
No benchmarks in this commit, assuming the results are similar (at least
for cs = Qt::CaseSensitive).

Task-number: QTBUG-119750
Change-Id: Ica7a43f6147b49c187ccfffd179e1f852272af8b
Reviewed-by: Marc Mutz <marc.mutz@qt.io>

4 files changed, 30 insertions, 12 deletions

diff --git a/src/corelib/text/qstring.cpp b/src/corelib/text/qstring.cpp
index 70f17ee290..410b65a62a 100644
--- a/src/corelib/text/qstring.cpp
+++ b/src/corelib/text/qstring.cpp
@@ -4414,14 +4414,11 @@ qsizetype QString::indexOf(QLatin1StringView str, qsizetype from, Qt::CaseSensit
 }
 
 /*!
+    \fn qsizetype QString::indexOf(QChar ch, qsizetype from, Qt::CaseSensitivity cs) const
     \overload indexOf()
 
     \include qstring.qdocinc {qstring-first-index-of} {character} {ch}
 */
-qsizetype QString::indexOf(QChar ch, qsizetype from, Qt::CaseSensitivity cs) const
-{
-    return qFindChar(QStringView(unicode(), size()), ch, from, cs);
-}
 
 /*!
   \include qstring.qdocinc {qstring-last-index-of} {string} {str}
@@ -4516,14 +4513,11 @@ qsizetype QString::lastIndexOf(QLatin1StringView str, qsizetype from, Qt::CaseSe
 */
 
 /*!
+  \fn qsizetype QString::lastIndexOf(QChar ch, qsizetype from, Qt::CaseSensitivity cs) const
   \overload lastIndexOf()
 
   \include qstring.qdocinc {qstring-last-index-of} {character} {ch}
 */
-qsizetype QString::lastIndexOf(QChar ch, qsizetype from, Qt::CaseSensitivity cs) const
-{
-    return qLastIndexOf(QStringView(*this), ch, from, cs);
-}
 
 /*!
   \fn QString::lastIndexOf(QChar ch, Qt::CaseSensitivity) const
@@ -9643,6 +9637,11 @@ bool QtPrivate::endsWith(QLatin1StringView haystack, QLatin1StringView needle, Q
     return qt_ends_with_impl(haystack, needle, cs);
 }
 
+qsizetype QtPrivate::findString(QStringView haystack0, qsizetype from, char16_t needle0, Qt::CaseSensitivity cs) noexcept
+{
+    return qFindChar(haystack0, needle0, from, cs);
+}
+
 qsizetype QtPrivate::findString(QStringView haystack0, qsizetype from, QStringView needle0, Qt::CaseSensitivity cs) noexcept
 {
     const qsizetype l = haystack0.size();
@@ -9802,6 +9801,11 @@ qsizetype QtPrivate::findString(QLatin1StringView haystack, qsizetype from, QLat
     return matcher.indexIn(haystack, from);
 }
 
+qsizetype QtPrivate::lastIndexOf(QStringView haystack, qsizetype from, char16_t needle, Qt::CaseSensitivity cs) noexcept
+{
+    return qLastIndexOf(haystack, QChar(needle), from, cs);
+}
+
 qsizetype QtPrivate::lastIndexOf(QStringView haystack, qsizetype from, QStringView needle, Qt::CaseSensitivity cs) noexcept
 {
     return qLastIndexOf(haystack, from, needle, cs);
diff --git a/src/corelib/text/qstring.h b/src/corelib/text/qstring.h
index 3e28d7727c..218a773005 100644
--- a/src/corelib/text/qstring.h
+++ b/src/corelib/text/qstring.h
@@ -273,14 +273,16 @@ public:
     static QString vasprintf(const char *format, va_list ap) Q_ATTRIBUTE_FORMAT_PRINTF(1, 0);
     static QString asprintf(const char *format, ...) Q_ATTRIBUTE_FORMAT_PRINTF(1, 2);
 
-    [[nodiscard]] qsizetype indexOf(QChar c, qsizetype from = 0, Qt::CaseSensitivity cs = Qt::CaseSensitive) const;
+    [[nodiscard]] QT_CORE_INLINE_SINCE(6, 7)
+    qsizetype indexOf(QChar c, qsizetype from = 0, Qt::CaseSensitivity cs = Qt::CaseSensitive) const;
     [[nodiscard]] qsizetype indexOf(QLatin1StringView s, qsizetype from = 0, Qt::CaseSensitivity cs = Qt::CaseSensitive) const;
     [[nodiscard]] qsizetype indexOf(const QString &s, qsizetype from = 0, Qt::CaseSensitivity cs = Qt::CaseSensitive) const;
     [[nodiscard]] qsizetype indexOf(QStringView s, qsizetype from = 0, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
     { return QtPrivate::findString(*this, from, s, cs); }
     [[nodiscard]] qsizetype lastIndexOf(QChar c, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
     { return lastIndexOf(c, -1, cs); }
-    [[nodiscard]] qsizetype lastIndexOf(QChar c, qsizetype from, Qt::CaseSensitivity cs = Qt::CaseSensitive) const;
+    [[nodiscard]] QT_CORE_INLINE_SINCE(6, 7)
+    qsizetype lastIndexOf(QChar c, qsizetype from, Qt::CaseSensitivity cs = Qt::CaseSensitive) const;
     [[nodiscard]] qsizetype lastIndexOf(QLatin1StringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const
     { return lastIndexOf(s, size(), cs); }
     [[nodiscard]] qsizetype lastIndexOf(QLatin1StringView s, qsizetype from, Qt::CaseSensitivity cs = Qt::CaseSensitive) const;
@@ -1462,6 +1464,16 @@ quint64 QString::toULongLong(bool *ok, int base) const
     return toIntegral_helper<qulonglong>(*this, ok, base);
 }
 #endif
+#if QT_CORE_INLINE_IMPL_SINCE(6, 7)
+qsizetype QString::indexOf(QChar ch, qsizetype from, Qt::CaseSensitivity cs) const
+{
+    return qToStringViewIgnoringNull(*this).indexOf(ch, from, cs);
+}
+qsizetype QString::lastIndexOf(QChar ch, qsizetype from, Qt::CaseSensitivity cs) const
+{
+    return qToStringViewIgnoringNull(*this).lastIndexOf(ch, from, cs);
+}
+#endif
 
 namespace QtPrivate {
 // used by qPrintable() and qUtf8Printable() macros
diff --git a/src/corelib/text/qstringalgorithms.h b/src/corelib/text/qstringalgorithms.h
index 1f145ae096..6a007173ab 100644
--- a/src/corelib/text/qstringalgorithms.h
+++ b/src/corelib/text/qstringalgorithms.h
@@ -52,11 +52,13 @@ namespace QtPrivate {
 [[nodiscard]] Q_CORE_EXPORT Q_DECL_PURE_FUNCTION bool endsWith(QLatin1StringView haystack, QStringView   needle, Qt::CaseSensitivity cs = Qt::CaseSensitive) noexcept;
 [[nodiscard]] Q_CORE_EXPORT Q_DECL_PURE_FUNCTION bool endsWith(QLatin1StringView haystack, QLatin1StringView needle, Qt::CaseSensitivity cs = Qt::CaseSensitive) noexcept;
 
+[[nodiscard]] Q_CORE_EXPORT Q_DECL_PURE_FUNCTION qsizetype findString(QStringView haystack, qsizetype from, char16_t needle, Qt::CaseSensitivity cs = Qt::CaseSensitive) noexcept;
 [[nodiscard]] Q_CORE_EXPORT Q_DECL_PURE_FUNCTION qsizetype findString(QStringView haystack, qsizetype from, QStringView needle, Qt::CaseSensitivity cs = Qt::CaseSensitive) noexcept;
 [[nodiscard]] Q_CORE_EXPORT Q_DECL_PURE_FUNCTION qsizetype findString(QStringView haystack, qsizetype from, QLatin1StringView needle, Qt::CaseSensitivity cs = Qt::CaseSensitive) noexcept;
 [[nodiscard]] Q_CORE_EXPORT Q_DECL_PURE_FUNCTION qsizetype findString(QLatin1StringView haystack, qsizetype from, QStringView needle, Qt::CaseSensitivity cs = Qt::CaseSensitive) noexcept;
 [[nodiscard]] Q_CORE_EXPORT Q_DECL_PURE_FUNCTION qsizetype findString(QLatin1StringView haystack, qsizetype from, QLatin1StringView needle, Qt::CaseSensitivity cs = Qt::CaseSensitive) noexcept;
 
+[[nodiscard]] Q_CORE_EXPORT Q_DECL_PURE_FUNCTION qsizetype lastIndexOf(QStringView haystack, qsizetype from, char16_t needle, Qt::CaseSensitivity cs = Qt::CaseSensitive) noexcept;
 [[nodiscard]] Q_CORE_EXPORT Q_DECL_PURE_FUNCTION qsizetype lastIndexOf(QStringView haystack, qsizetype from, QStringView needle, Qt::CaseSensitivity cs = Qt::CaseSensitive) noexcept;
 [[nodiscard]] Q_CORE_EXPORT Q_DECL_PURE_FUNCTION qsizetype lastIndexOf(QStringView haystack, qsizetype from, QLatin1StringView needle, Qt::CaseSensitivity cs = Qt::CaseSensitive) noexcept;
 [[nodiscard]] Q_CORE_EXPORT Q_DECL_PURE_FUNCTION qsizetype lastIndexOf(QLatin1StringView haystack, qsizetype from, QStringView needle, Qt::CaseSensitivity cs = Qt::CaseSensitive) noexcept;
diff --git a/src/corelib/text/qstringview.h b/src/corelib/text/qstringview.h
index 3d1853c7a0..a598d7a445 100644
--- a/src/corelib/text/qstringview.h
+++ b/src/corelib/text/qstringview.h
@@ -263,7 +263,7 @@ public:
     { return QtPrivate::endsWith(*this, QStringView(&c, 1), cs); }
 
     [[nodiscard]] qsizetype indexOf(QChar c, qsizetype from = 0, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
-    { return QtPrivate::findString(*this, from, QStringView(&c, 1), cs); }
+    { return QtPrivate::findString(*this, from, c.unicode(), cs); }
     [[nodiscard]] qsizetype indexOf(QStringView s, qsizetype from = 0, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
     { return QtPrivate::findString(*this, from, s, cs); }
     [[nodiscard]] inline qsizetype indexOf(QLatin1StringView s, qsizetype from = 0, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept;
@@ -283,7 +283,7 @@ public:
     [[nodiscard]] qsizetype lastIndexOf(QChar c, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
     { return lastIndexOf(c, -1, cs); }
     [[nodiscard]] qsizetype lastIndexOf(QChar c, qsizetype from, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
-    { return QtPrivate::lastIndexOf(*this, from, QStringView(&c, 1), cs); }
+    { return QtPrivate::lastIndexOf(*this, from, c.unicode(), cs); }
     [[nodiscard]] qsizetype lastIndexOf(QStringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
     { return lastIndexOf(s, size(), cs); }
     [[nodiscard]] qsizetype lastIndexOf(QStringView s, qsizetype from, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept