2 files changed, 28 insertions, 0 deletions
diff --git a/src/corelib/io/qdebug.cpp b/src/corelib/io/qdebug.cpp
index 5c42ee2e1cf..4f6b1696eb9 100644
--- a/src/corelib/io/qdebug.cpp
+++ b/src/corelib/io/qdebug.cpp
@@ -1019,6 +1019,15 @@ QDebug &QDebug::resetFormat()
 */
 
 /*!
+    \since 6.7
+    \fn template <class T> QDebug operator<<(QDebug debug, const std::optional<T> &opt)
+    \relates QDebug
+
+    Writes the contents of \a opt (or \c nullopt if not set) to \a debug.
+    \c T needs to support streaming into QDebug.
+*/
+
+/*!
     \fn template <typename T> QDebug operator<<(QDebug debug, const QContiguousCache<T> &cache)
     \relates QDebug
 
@@ -1051,6 +1060,13 @@ QDebug &QDebug::resetFormat()
  */
 
 /*!
+    \since 6.7
+    \fn QDebug &QDebug::operator<<(std::nullopt_t)
+
+    Writes nullopt to the stream.
+*/
+
+/*!
     \class QDebugStateSaver
     \inmodule QtCore
     \brief Convenience class for custom QDebug operators.
diff --git a/src/corelib/io/qdebug.h b/src/corelib/io/qdebug.h
index f5a35236e1a..770f4fac9a8 100644
--- a/src/corelib/io/qdebug.h
+++ b/src/corelib/io/qdebug.h
@@ -126,6 +126,7 @@ public:
     inline QDebug &operator<<(QByteArrayView t) { putByteArray(t.constData(), t.size(), ContainsBinary); return maybeSpace(); }
     inline QDebug &operator<<(const void * t) { stream->ts << t; return maybeSpace(); }
     inline QDebug &operator<<(std::nullptr_t) { stream->ts << "(nullptr)"; return maybeSpace(); }
+    inline QDebug &operator<<(std::nullopt_t) { stream->ts << "nullopt"; return maybeSpace(); }
     inline QDebug &operator<<(QTextStreamFunction f) {
         stream->ts << f;
         return *this;
@@ -361,6 +362,17 @@ inline QDebugIfHasDebugStreamContainer<QMultiHash<Key, T>, Key, T> operator<<(QD
     return QtPrivate::printAssociativeContainer(debug, "QMultiHash", hash);
 }
 
+template <class T>
+inline QDebugIfHasDebugStream<T> operator<<(QDebug debug, const std::optional<T> &opt)
+{
+    const QDebugStateSaver saver(debug);
+    if (!opt)
+        debug.nospace() << std::nullopt;
+    else
+        debug.nospace() << "std::optional(" << *opt << ')';
+    return debug;
+}
+
 template <class T1, class T2>
 inline QDebugIfHasDebugStream<T1, T2> operator<<(QDebug debug, const std::pair<T1, T2> &pair)
 {