QStringBuilder: add support for char16_t{,*,[]}

[ChangeLog][QtCore][QStringBuilder] Added support for char16_t
characters and strings.

Change-Id: Iee727f07226f2a326ae0df28d44930336cd8f71e
Reviewed-by: Milian Wolff <milian.wolff@kdab.com>
Reviewed-by: Olivier Goffart (Woboq GmbH) <ogoffart@woboq.com>
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>

1 files changed, 52 insertions, 0 deletions

diff --git a/src/corelib/tools/qstringbuilder.h b/src/corelib/tools/qstringbuilder.h
index 5c6d990314..e9ca2245ba 100644
--- a/src/corelib/tools/qstringbuilder.h
+++ b/src/corelib/tools/qstringbuilder.h
@@ -187,6 +187,18 @@ template <> struct QConcatenable<char> : private QAbstractConcatenable
     { *out++ = c; }
 };
 
+#if defined(Q_COMPILER_UNICODE_STRINGS)
+template <> struct QConcatenable<char16_t> : private QAbstractConcatenable
+{
+    typedef char16_t type;
+    typedef QString ConvertTo;
+    enum { ExactSize = true };
+    static Q_DECL_CONSTEXPR int size(char16_t) { return 1; }
+    static inline void appendTo(char16_t c, QChar *&out)
+    { *out++ = c; }
+};
+#endif
+
 template <> struct QConcatenable<QLatin1Char>
 {
     typedef QLatin1Char type;
@@ -325,6 +337,46 @@ template <> struct QConcatenable<char *> : QConcatenable<const char*>
     typedef char *type;
 };
 
+#if defined(Q_COMPILER_UNICODE_STRINGS)
+template <int N> struct QConcatenable<const char16_t[N]> : private QAbstractConcatenable
+{
+    using type = const char16_t[N];
+    using ConvertTo = QString;
+    enum { ExactSize = true };
+    static int size(const char16_t[N]) { return N - 1; }
+    static void appendTo(const char16_t a[N], QChar *&out)
+    {
+        memcpy(out, a, (N - 1) * sizeof(char16_t));
+        out += N - 1;
+    }
+};
+
+template <int N> struct QConcatenable<char16_t[N]> : QConcatenable<const char16_t[N]>
+{
+    using type = char16_t[N];
+};
+
+template <> struct QConcatenable<const char16_t *> : private QAbstractConcatenable
+{
+    using type = const char16_t *;
+    using ConvertTo = QString;
+    enum { ExactSize = true };
+    static int size(const char16_t *a) { return QStringView(a).length(); };
+    static inline void QT_ASCII_CAST_WARN appendTo(const char16_t *a, QChar *&out)
+    {
+        if (!a)
+            return;
+        while (*a)
+            *out++ = *a++;
+    }
+};
+
+template <> struct QConcatenable<char16_t *> : QConcatenable<const char16_t*>
+{
+    typedef char16_t *type;
+};
+#endif // UNICODE_STRINGS
+
 template <> struct QConcatenable<QByteArray> : private QAbstractConcatenable
 {
     typedef QByteArray type;