Improve Map|Map-Reduce and Filter|Filter-Reduce implementation

* support lambda expressions
* remove the need to specify result_type
* use std::invoke to apply map|filter function
* remove usage of FunctionWrapper* and createFunctionWrapper

Task-number: QTBUG-33735
Task-number: QTBUG-82646
Change-Id: Ibcbe4278f0742c29182bd506081db0abb516f85f
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
Reviewed-by: Sona Kurazyan <sona.kurazyan@qt.io>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/concurrent/qtconcurrentreducekernel.h b/src/concurrent/qtconcurrentreducekernel.h
index eabc432374..a487ec26a2 100644
--- a/src/concurrent/qtconcurrentreducekernel.h
+++ b/src/concurrent/qtconcurrentreducekernel.h
@@ -124,7 +124,7 @@ class ReduceKernel
                       const IntermediateResults<T> &result)
     {
         for (int i = 0; i < result.vector.size(); ++i) {
-            reduce(r, result.vector.at(i));
+            std::invoke(reduce, r, result.vector.at(i));
         }
     }