Fix Clang 10 warnings about deprecated copy constructors

 qstring.h:1235:22: warning: definition of implicit copy constructor for 'QCharRef' is deprecated because it has a
 user-declared copy assignment operator [-Wdeprecated-copy]

Task-number: QTBUG-83666
Change-Id: I99ab0f318b1c43b89888fffd160b4a12bee11723
Reviewed-by: Marc Mutz <marc.mutz@kdab.com>

4 files changed, 4 insertions, 0 deletions

diff --git a/src/corelib/serialization/qjsonvalue.h b/src/corelib/serialization/qjsonvalue.h
index 5adcd64176..3b5c0545fc 100644
--- a/src/corelib/serialization/qjsonvalue.h
+++ b/src/corelib/serialization/qjsonvalue.h
@@ -158,6 +158,7 @@ private:
 class Q_CORE_EXPORT QJsonValueRef
 {
 public:
+    QJsonValueRef(const QJsonValueRef &) = default; // ### Qt6: delete (maybe)
     QJsonValueRef(QJsonArray *array, int idx)
         : a(array), is_object(false), index(static_cast<uint>(idx)) {}
     QJsonValueRef(QJsonObject *object, int idx)
diff --git a/src/corelib/text/qbytearray.h b/src/corelib/text/qbytearray.h
index dac4f05a40..2b7d298313 100644
--- a/src/corelib/text/qbytearray.h
+++ b/src/corelib/text/qbytearray.h
@@ -568,6 +568,7 @@ QByteRef {  // ### Qt 7: remove
         : a(array),i(idx) {}
     friend class QByteArray;
 public:
+    QByteRef(const QByteRef &) = default;
     inline operator char() const
     {
         using namespace QtPrivate::DeprecatedRefClassBehavior;
diff --git a/src/corelib/text/qstring.h b/src/corelib/text/qstring.h
index 99b41c8ebf..f446c35e40 100644
--- a/src/corelib/text/qstring.h
+++ b/src/corelib/text/qstring.h
@@ -1186,6 +1186,7 @@ QCharRef { // ### Qt 7: remove
         : s(str),i(idx) {}
     friend class QString;
 public:
+    QCharRef(const QCharRef &) = default;
 
     // most QChar operations repeated here
 
diff --git a/src/corelib/tools/qbitarray.h b/src/corelib/tools/qbitarray.h
index 9b0e931aca..eaed17413d 100644
--- a/src/corelib/tools/qbitarray.h
+++ b/src/corelib/tools/qbitarray.h
@@ -149,6 +149,7 @@ private:
     inline QBitRef(QBitArray& array, int idx) : a(array), i(idx) {}
     friend class QBitArray;
 public:
+    QBitRef(const QBitRef &) = default;
     inline operator bool() const { return a.testBit(i); }
     inline bool operator!() const { return !a.testBit(i); }
     QBitRef& operator=(const QBitRef& val) { a.setBit(i, val); return *this; }