QString, QByteArray: add erase(iterator) method

Fixes: QTBUG-106182
Change-Id: Idc74cc643b90252838ca1a9ca40a330315da421f
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/text/qbytearray.cpp

@@ -1271,6 +1271,21 @@ QByteArray::iterator QByteArray::erase(QByteArray::const_iterator first, QByteAr
     return begin() + start;
 }
 
+/*!
+    \fn QByteArray::iterator QByteArray::erase(QByteArray::const_iterator it)
+
+    \since 6.5
+
+    Removes the character denoted by \c it from the byte array.
+    Returns an iterator to the character immediately after the
+    erased character.
+
+    \code
+    QByteArray ba = "abcdefg";
+    auto it = ba.erase(ba.cbegin()); // ba is now "bcdefg" and it points to "b"
+    \endcode
+*/
+
 /*! \fn QByteArray::QByteArray(const QByteArray &other)
 
     Constructs a copy of \a other.

src/corelib/text/qbytearray.h

@@ -429,6 +429,7 @@ public:
     { prepend(a); }
     void shrink_to_fit() { squeeze(); }
     iterator erase(const_iterator first, const_iterator last);
+    inline iterator erase(const_iterator it) { return erase(it, it + 1); }
 
     static QByteArray fromStdString(const std::string &s);
     std::string toStdString() const;

src/corelib/text/qstring.cpp

@@ -8935,7 +8935,8 @@ bool QString::isRightToLeft() const
 
     Removes from the string the characters in the half-open range
     [ \a first , \a last ). Returns an iterator to the character
-    referred to by \a last before the erase.
+    immediately after the last erased character (i.e. the character
+    referred to by \a last before the erase).
 */
 QString::iterator QString::erase(QString::const_iterator first, QString::const_iterator last)
 {
@@ -8945,6 +8946,21 @@ QString::iterator QString::erase(QString::const_iterator first, QString::const_i
     return begin() + start;
 }
 
+/*!
+    \fn QString::iterator QString::erase(QString::const_iterator it)
+
+    \since 6.5
+
+    Removes the character denoted by \c it from the string.
+    Returns an iterator to the character immediately after the
+    erased character.
+
+    \code
+    QString c = "abcdefg";
+    auto it = c.erase(c.cbegin()); // c is now "bcdefg"; "it" points to "b"
+    \endcode
+*/
+
 /*! \fn void QString::shrink_to_fit()
     \since 5.10
 

src/corelib/text/qstring.h

@@ -1086,6 +1086,7 @@ public:
     inline void push_front(const QString &s) { prepend(s); }
     void shrink_to_fit() { squeeze(); }
     iterator erase(const_iterator first, const_iterator last);
+    inline iterator erase(const_iterator it) { return erase(it, it + 1); }
 
     static inline QString fromStdString(const std::string &s);
     inline std::string toStdString() const;

tests/auto/corelib/text/qbytearray/tst_qbytearray.cpp

@@ -68,6 +68,7 @@ private slots:
     void remove_data();
     void remove();
     void removeIf();
+    void erase_single_arg();
     void replace_data();
     void replace();
     void replaceWithSpecifiedLength();
@@ -1272,6 +1273,22 @@ void tst_QByteArray::removeIf()
     QCOMPARE(a.removeIf(removeA), QByteArray("BcbC"));
 }
 
+void tst_QByteArray::erase_single_arg()
+{
+    QByteArray ba = "abcdefg";
+    ba.erase(ba.cend());
+    auto it = ba.erase(ba.cbegin());
+    QCOMPARE_EQ(ba, "bcdefg");
+    QCOMPARE(it, ba.cbegin());
+
+    it = ba.erase(std::prev(ba.end()));
+    QCOMPARE_EQ(ba, "bcdef");
+    QCOMPARE(it, ba.cend());
+
+    it = ba.erase(std::find(ba.begin(), ba.end(), QChar('d')));
+    QCOMPARE(it, ba.begin() + 2);
+}
+
 void tst_QByteArray::replace_data()
 {
     // Try to cover both the index and specific char cases.

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

@@ -366,6 +366,8 @@ private slots:
     void remove_regexp();
 #endif
     void remove_extra();
+    void erase_single_arg();
+    void erase();
     void swap();
 
     void prepend_qstring()            { prepend_impl<QString>(); }
@@ -3424,6 +3426,44 @@ void tst_QString::remove_extra()
     }
 }
 
+void tst_QString::erase_single_arg()
+{
+    QString s = "abcdefg";
+    auto it = s.erase(s.cbegin());
+    QCOMPARE_EQ(s, "bcdefg");
+    QCOMPARE(it, s.cbegin());
+
+    it = s.erase(std::prev(s.end()));
+    QCOMPARE_EQ(s, "bcdef");
+    QCOMPARE(it, s.cend());
+
+    it = s.erase(std::find(s.begin(), s.end(), QChar('d')));
+    QCOMPARE(it, s.begin() + 2);
+}
+
+void tst_QString::erase()
+{
+    QString str = "abcdefg";
+
+    QString s = str;
+    auto it = s.erase(s.begin(), s.end());
+    QCOMPARE_EQ(s, "");
+    QCOMPARE(it, s.end());
+
+    s = str;
+    it = s.erase(std::prev(s.end()));
+    QCOMPARE_EQ(s, "abcdef");
+    QCOMPARE(it, s.end());
+
+    it = s.erase(s.begin() + 2, s.end());
+    QCOMPARE_EQ(s, "ab");
+    QCOMPARE(it, s.end());
+
+    it = s.erase(s.begin(), s.begin() + 1);
+    QCOMPARE_EQ(s, "b");
+    QCOMPARE(it, s.begin());
+}
+
 void tst_QString::toNum()
 {
 #if defined (Q_OS_WIN) && defined (Q_CC_MSVC)