From 48ab909c5d34f024ec8f1c44cfb5b373e8689ba4 Mon Sep 17 00:00:00 2001
From: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>
Date: Fri, 24 May 2024 14:34:23 +0200
Subject: [PATCH] QDateTime::fromStdTimePoint: remove an unnecessary
 time_point_cast

The constraint now checks that the result of the clock_cast has a
duration which is convertible to milliseconds, so just do the
implicit conversion, without any cast for the duration.

Task-number: QTBUG-125587
Change-Id: Id2c8232d756318c3e4d33cd7e1556773961a9dba
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
---
 src/corelib/time/qdatetime.h | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/src/corelib/time/qdatetime.h b/src/corelib/time/qdatetime.h
index 70a79a4f874..77247dcd078 100644
--- a/src/corelib/time/qdatetime.h
+++ b/src/corelib/time/qdatetime.h
@@ -543,10 +543,9 @@ public:
                 >;
             }
     {
-        const auto sysTime = std::chrono::clock_cast<std::chrono::system_clock>(time);
-        // clock_cast can change the duration, so convert it again to milliseconds
-        const auto timeInMSec = std::chrono::time_point_cast<std::chrono::milliseconds>(sysTime);
-        return fromStdTimePoint(timeInMSec);
+        using namespace std::chrono;
+        const sys_time<milliseconds> sysTime = clock_cast<system_clock>(time);
+        return fromStdTimePoint(sysTime);
     }
 #endif // __cpp_concepts