QLatin1String: add chopped(), chop(), and truncate()

[ChangeLog][QtCore][QLatin1String] Added chopped(), chop(),
truncate().

Change-Id: I69b31aae560e94a120d7e8a36e06ea957ccd2003
Reviewed-by: Anton Kudryavtsev <antkudr@mail.ru>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

src/corelib/tools/qstring.cpp

@@ -8961,7 +8961,7 @@ QString &QString::setRawData(const QChar *unicode, int size)
     \note This function performs no error checking.
     The behavior is undefined when \a start < 0 or \a start > size().
 
-    \sa left(), right()
+    \sa left(), right(), chopped(), chop(), truncate()
 */
 
 /*! \fn QLatin1String QLatin1String::mid(int start, int length) const
@@ -8975,7 +8975,7 @@ QString &QString::setRawData(const QChar *unicode, int size)
     The behavior is undefined when \a start < 0, \a length < 0,
     or \a start + \a length > size().
 
-    \sa left(), right()
+    \sa left(), right(), chopped(), chop(), truncate()
 */
 
 /*! \fn QLatin1String QLatin1String::left(int length) const
@@ -8987,7 +8987,7 @@ QString &QString::setRawData(const QChar *unicode, int size)
     \note This function performs no error checking.
     The behavior is undefined when \a length < 0 or \a length > size().
 
-    \sa mid(), right()
+    \sa mid(), right(), chopped(), chop(), truncate()
 */
 
 /*! \fn QLatin1String QLatin1String::right(int length) const
@@ -8999,7 +8999,47 @@ QString &QString::setRawData(const QChar *unicode, int size)
     \note This function performs no error checking.
     The behavior is undefined when \a length < 0 or \a length > size().
 
-    \sa mid(), left()
+    \sa mid(), left(), chopped(), chop(), truncate()
+*/
+
+/*!
+    \fn QLatin1String QLatin1String::chopped(int length) const
+    \since 5.10
+
+    Returns the substring of length size() - \a length starting at the
+    beginning of this object.
+
+    Same as \c{left(size() - length)}.
+
+    \note The behavior is undefined when \a length < 0 or \a length > size().
+
+    \sa mid(), left(), right(), chop(), truncate()
+*/
+
+/*!
+    \fn void QLatin1String::truncate(int length)
+    \since 5.10
+
+    Truncates this string to length \a length.
+
+    Same as \c{*this = left(length)}.
+
+    \note The behavior is undefined when \a length < 0 or \a length > size().
+
+    \sa mid(), left(), right(), chopped(), chop()
+*/
+
+/*!
+    \fn void QLatin1String::chop(int length)
+    \since 5.10
+
+    Truncates this string by \a length characters.
+
+    Same as \c{*this = left(size() - length)}.
+
+    \note The behavior is undefined when \a length < 0 or \a length > size().
+
+    \sa mid(), left(), right(), chopped(), truncate()
 */
 
 /*! \fn bool QLatin1String::operator==(const QString &other) const

src/corelib/tools/qstring.h

@@ -152,6 +152,13 @@ public:
     { return Q_ASSERT(n >= 0), Q_ASSERT(n <= size()), QLatin1String(m_data, n); }
     Q_DECL_CONSTEXPR QLatin1String right(int n) const
     { return Q_ASSERT(n >= 0), Q_ASSERT(n <= size()), QLatin1String(m_data + m_size - n, n); }
+    Q_DECL_CONSTEXPR QLatin1String chopped(int n) const Q_REQUIRED_RESULT
+    { return Q_ASSERT(n >= 0), Q_ASSERT(n <= size()), QLatin1String(m_data, m_size - n); }
+
+    Q_DECL_RELAXED_CONSTEXPR void chop(int n)
+    { Q_ASSERT(n >= 0); Q_ASSERT(n <= size()); m_size -= n; }
+    Q_DECL_RELAXED_CONSTEXPR void truncate(int n)
+    { Q_ASSERT(n >= 0); Q_ASSERT(n <= size()); m_size = n; }
 
     inline bool operator==(const QString &s) const Q_DECL_NOTHROW;
     inline bool operator!=(const QString &s) const Q_DECL_NOTHROW;

tests/auto/corelib/tools/qstringapisymmetry/tst_qstringapisymmetry.cpp

@@ -238,6 +238,8 @@ private Q_SLOTS:
     void chop_QStringRef() { chop_impl<QStringRef>(); }
     void chop_QStringView_data() { chop_data(); }
     void chop_QStringView() { chop_impl<QStringView>(); }
+    void chop_QLatin1String_data() { chop_data(); }
+    void chop_QLatin1String() { chop_impl<QLatin1String>(); }
     void chop_QByteArray_data() { chop_data(); }
     void chop_QByteArray() { chop_impl<QByteArray>(); }
 
@@ -247,6 +249,8 @@ private Q_SLOTS:
     void truncate_QStringRef() { truncate_impl<QStringRef>(); }
     void truncate_QStringView_data() { truncate_data(); }
     void truncate_QStringView() { truncate_impl<QStringView>(); }
+    void truncate_QLatin1String_data() { truncate_data(); }
+    void truncate_QLatin1String() { truncate_impl<QLatin1String>(); }
     void truncate_QByteArray_data() { truncate_data(); }
     void truncate_QByteArray() { truncate_impl<QByteArray>(); }