https://bugs.gentoo.org/764977
https://invent.kde.org/qt/qt/qtbase/-/commit/c9543da6998b0827fb75ffe22327c99e2da7d364

From c9543da6998b0827fb75ffe22327c99e2da7d364 Mon Sep 17 00:00:00 2001
From: Sona Kurazyan <sona.kurazyan@qt.io>
Date: Wed, 17 Mar 2021 16:04:00 +0100
Subject: [PATCH] Remove the unnecessary template parameter from the class
 specialization
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This seems to cause errors when compiling with gcc-11. Although this is
most likely a compiler bug, specifiying the template parameter type in
this case isn't necessary.

Fixes: QTBUG-91909
Fixes: QTBUG-90568
Change-Id: Ib231257ccb2e16cc533f23ca5840d31e26a66d53
Reviewed-by: MÃ¥rten Nordheim <marten.nordheim@qt.io>
(cherry picked from commit 659f7a06e91c04b239e3f4c0bcfccbe3581af1c3)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
(cherry picked from commit 049e14870c13235cd066758f29c42dc96c1ccdf8)
---
 src/concurrent/qtconcurrentthreadengine.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/concurrent/qtconcurrentthreadengine.h b/src/concurrent/qtconcurrentthreadengine.h
index af413707e4..a4c8548cc4 100644
--- a/src/concurrent/qtconcurrentthreadengine.h
+++ b/src/concurrent/qtconcurrentthreadengine.h
@@ -247,8 +247,8 @@ template <>
 class ThreadEngineStarter<void> : public ThreadEngineStarterBase<void>
 {
 public:
-    ThreadEngineStarter<void>(ThreadEngine<void> *_threadEngine)
-    :ThreadEngineStarterBase<void>(_threadEngine) {}
+    ThreadEngineStarter(ThreadEngine<void> *_threadEngine)
+        : ThreadEngineStarterBase<void>(_threadEngine) {}
 
     void startBlocking()
     {
-- 
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