Fixed ParallelForExample

The example should be the same for both .cpp and .cu, otherwise the
output might be inconsistent (e.g. when .cpp is included, but .cu is
compiled and its output is used).

Documentation/Examples/Algorithms/ParallelForExample.cu

-#include <iostream>
-#include <cstdlib>
-#include <TNL/Containers/Vector.h>
-#include <TNL/Algorithms/ParallelFor.h>
-
-using namespace TNL;
-using namespace TNL::Containers;
-using namespace TNL::Algorithms;
-
-template< typename Device >
-void vectorSum( const Vector< double, Device >& v1,
-                const Vector< double, Device >& v2,
-                const double& c,
-                Vector< double, Device >& result )
-{
-   /****
-    * Get vectors view which can be captured by lambda.
-    */
-   auto v1_view = v1.getConstView();
-   auto v2_view = v2.getConstView();
-   auto result_view = result.getView();
-
-   /****
-    * The sum function.
-    */
-   auto sum = [=] __cuda_callable__  ( int i, const double c ) mutable {
-      result_view[ i ] = v1_view[ i ] + v2_view[ i ] + c; };
-
-      ParallelFor< Device >::exec( 0, v1.getSize(), sum, c );
-}
-
-int main( int argc, char* argv[] )
-{
-   /***
-    * Firstly, test the vectors sum on CPU.
-    */
-   Vector< double, Devices::Host > host_v1( 10 ), host_v2( 10 ), host_result( 10 );
-   host_v1 = 1.0;
-   host_v2.forAllElements( []__cuda_callable__ ( int i, double& v ) { v = i; } );
-   vectorSum( host_v1, host_v2, 2.0, host_result );
-   std::cout << "host_v1 = " << host_v1 << std::endl;
-   std::cout << "host_v2 = " << host_v2 << std::endl;
-   std::cout << "The sum of the vectors on CPU is " << host_result << "." << std::endl;
-
-   /***
-    * And then also on GPU.
-    */
-#ifdef HAVE_CUDA
-   Vector< double, Devices::Cuda > cuda_v1( 10 ), cuda_v2( 10 ), cuda_result( 10 );
-   cuda_v1 = 1.0;
-   cuda_v2.forAllElements( []__cuda_callable__ ( int i, double& v ) { v = i; } );
-   vectorSum( cuda_v1, cuda_v2, 2.0, cuda_result );
-   std::cout << "cuda_v1 = " << cuda_v1 << std::endl;
-   std::cout << "cuda_v2 = " << cuda_v2 << std::endl;
-   std::cout << "The sum of the vectors on GPU is " << cuda_result << "." << std::endl;
-#endif
-   return EXIT_SUCCESS;
-}
-

Documentation/Examples/Algorithms/ParallelForExample.cu

+ParallelForExample.cpp
\ No newline at end of file