From e5e560c7fdbd2d8c0ffef1f07add0acf738202c8 Mon Sep 17 00:00:00 2001
From: Marc Mutz <marc.mutz@qt.io>
Date: Thu, 24 Oct 2024 14:35:32 +0200
Subject: [PATCH] QDebug: simplify op<<(std::optional)

We don't need to enable nospace() if we stream but a single element
(nullopt). As a consequence, delay construction of the StateSaver
until we have determined that the optional is engaged.

Amends b7657ddccbe0a5ab1cdfc61ae6b7f0501dbfb24a.

Change-Id: Id974dff078cb989b92f84b63bf14956a2fba32b2
Reviewed-by: David Faure <david.faure@kdab.com>
(cherry picked from commit 25931bf2181706e1cba416b0530f07959182f074)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
---
 src/corelib/io/qdebug.h | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/src/corelib/io/qdebug.h b/src/corelib/io/qdebug.h
index b68c96c7182..97dde132366 100644
--- a/src/corelib/io/qdebug.h
+++ b/src/corelib/io/qdebug.h
@@ -392,11 +392,10 @@ inline QDebugIfHasDebugStreamContainer<QMultiHash<Key, T>, Key, T> operator<<(QD
 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 << std::nullopt;
+    const QDebugStateSaver saver(debug);
+    debug.nospace() << "std::optional(" << *opt << ')';
     return debug;
 }