// This example demonstrates how to create a parallel-reduction task.

#include 
#include 

struct Data {
  int a {::rand()};
  int b {::rand()};
  int transform() const {
    return a*a + 2*a*b + b*b;
  }
};

// Procedure: reduce
// This procedure demonstrates
void reduce(size_t N) {

  std::cout