QTextStream: complete char16_t support

... by providing also op>> for char16_t.

[ChangeLog][QtCore][QTextStream] Added op>>(char16_t&).

Change-Id: I2f6cc2b2cdacd5190d364f94c1830f6de62d3b7e
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>

src/corelib/serialization/qtextstream.cpp

@@ -1995,6 +1995,14 @@ QTextStream &QTextStream::operator>>(char &c)
     return *this;
 }
 
+/*!
+    \fn QTextStream &QTextStream::operator>>(char16_t &c)
+    \overload
+    \since 6.4
+
+    Reads a character from the stream and stores it in \a c.
+*/
+
 /*!
     Reads an integer from the stream and stores it in \a i, then
     returns a reference to the QTextStream. The number is cast to

src/corelib/serialization/qtextstream.h

@@ -153,6 +153,8 @@ public:
 
     QTextStream &operator>>(QChar &ch);
     QTextStream &operator>>(char &ch);
+    QTextStream &operator>>(char16_t &ch)
+    { QChar c; *this >> c; ch = c.unicode(); return *this; }
     QTextStream &operator>>(signed short &i);
     QTextStream &operator>>(unsigned short &i);
     QTextStream &operator>>(signed int &i);

tests/auto/corelib/serialization/qtextstream/tst_qtextstream.cpp

@@ -1929,10 +1929,19 @@ void tst_QTextStream::char16_t_operators_FromDevice_data()
 // ------------------------------------------------------------------------------
 void tst_QTextStream::char16_t_operators_FromDevice()
 {
+    QFETCH(QByteArray, input);
     QFETCH(const QChar, qchar_output);
     QFETCH(const QByteArray, write_output);
     const char16_t char16_t_output = qchar_output.unicode();
 
+    QBuffer buf(&input);
+    buf.open(QBuffer::ReadOnly);
+    QTextStream stream(&buf);
+    stream.setEncoding(QStringConverter::Latin1);
+    char16_t tmp;
+    stream >> tmp;
+    QCOMPARE(tmp, qchar_output);
+
     QBuffer writeBuf;
     writeBuf.open(QBuffer::WriteOnly);