From 8365322d3de709e86fc6c3962472dcc8944fb0a3 Mon Sep 17 00:00:00 2001
From: Vitaly Fanaskov <vitaly.fanaskov@qt.io>
Date: Tue, 31 Mar 2020 16:24:29 +0200
Subject: [PATCH] StoredFunctionCall: simplify runFunctor implementation
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Task-number: QTBUG-82383
Change-Id: Ib8e196106c80e8f3aba1ff7d0c8b76a547c648da
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
---
 src/concurrent/qtconcurrentstoredfunctioncall.h | 15 ++++-----------
 1 file changed, 4 insertions(+), 11 deletions(-)

diff --git a/src/concurrent/qtconcurrentstoredfunctioncall.h b/src/concurrent/qtconcurrentstoredfunctioncall.h
index f64648d7e96..b879e8af451 100644
--- a/src/concurrent/qtconcurrentstoredfunctioncall.h
+++ b/src/concurrent/qtconcurrentstoredfunctioncall.h
@@ -80,20 +80,13 @@ struct StoredFunctionCall : public RunFunctionTask<InvokeResultType<Function, Ar
 
     void runFunctor() override
     {
-        using Indexes =
-            std::make_index_sequence<
-                std::tuple_size<DecayedTuple<Function, Args...>>::value>;
+        constexpr auto invoke = &std::invoke<std::decay_t<Function>,
+                                             std::decay_t<Args>...>;
 
-        invoke(Indexes());
-    }
-
-    template <std::size_t... I>
-    void invoke(std::index_sequence<I...>)
-    {
         if constexpr (std::is_void_v<InvokeResultType<Function, Args...>>)
-            std::invoke(std::get<I>(std::move(data))...);
+            std::apply(invoke, std::move(data));
         else
-            this->result = std::invoke(std::get<I>(std::move(data))...);
+            this->result = std::apply(invoke, std::move(data));
     }
 
     DecayedTuple<Function, Args...> data;