QStringView: add constructor from pointer pair

This is often more natural than (ptr, len), and I need it in the
implementation of QStringView::trimmed().

Change-Id: I1d99b5ddaf76eee0582150b0233ef6ce9c37d25d
Reviewed-by: Anton Kudryavtsev <antkudr@mail.ru>
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>

2 files changed, 24 insertions, 0 deletions

diff --git a/src/corelib/tools/qstringview.cpp b/src/corelib/tools/qstringview.cpp
index 0b1dac2f98..8d2fc996e9 100644
--- a/src/corelib/tools/qstringview.cpp
+++ b/src/corelib/tools/qstringview.cpp
@@ -240,6 +240,26 @@ QT_BEGIN_NAMESPACE
 */
 
 /*!
+    \fn QStringView::QStringView(const Char *first, const Char *last)
+
+    Constructs a string view on \a first with length (\a last - \a first).
+
+    The range \c{[first,last)} must remain valid for the lifetime of
+    this string view object.
+
+    Passing \c nullptr as \a first is safe if \a last is nullptr, too,
+    and results in a null string view.
+
+    The behavior is undefined if \a last precedes \a first, or \a first
+    is \c nullptr and \a last is not.
+
+    This constructor only participates in overload resolution if \c Char
+    is a compatible character type. The compatible character types
+    are: \c QChar, \c ushort, \c char16_t and (on platforms, such as
+    Windows, where it is a 16-bit type) \c wchar_t.
+*/
+
+/*!
     \fn QStringView::QStringView(const Char *str)
 
     Constructs a string view on \a str. The length is determined
diff --git a/src/corelib/tools/qstringview.h b/src/corelib/tools/qstringview.h
index 62173f9765..fdbf644518 100644
--- a/src/corelib/tools/qstringview.h
+++ b/src/corelib/tools/qstringview.h
@@ -176,6 +176,10 @@ public:
         : m_size((Q_ASSERT(len >= 0), Q_ASSERT(str || !len), len)),
           m_data(castHelper(str)) {}
 
+    template <typename Char, if_compatible_char<Char> = true>
+    Q_DECL_CONSTEXPR QStringView(const Char *f, const Char *l)
+        : QStringView(f, l - f) {}
+
 #ifdef Q_QDOC
     template <typename Char, size_t N>
     Q_DECL_CONSTEXPR QStringView(const Char (&array)[N]) Q_DECL_NOTHROW;