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  1. // future example
  2. #include <future>         // std::async, std::future
  3. #include <cmath>          // std::sqrt
  4. #include <iostream>       // std::cout
  5.  
  6. const int N = 1000;
  7.  
  8. int main ()
  9. {
  10. 	double *a = new double[N];
  11. 	double *b = new double[N];
  12. 	for (int i = 0; i < N; ++i)
  13. 	{
  14. 		a[i] = i;
  15. 	}
  16.  
  17. 	std::future<void> *futures = new std::future<void>[N];
  18. 	for (int i = 0; i < N; ++i)
  19. 	{
  20. 		futures[i] = std::async([&a, &b, i]
  21. 		{
  22. 			b[i] = std::sqrt(a[i]);
  23. 		});
  24. 	}
  25. 	/*
  26. 	for (int i = 0; i < N; ++i)
  27. 	{
  28. 		futures[i].get();
  29. 	}*/
  30.  
  31. 	for (int i = 0; i < N; ++i)
  32. 	{
  33. 		std::cout << b[i] << std::endl;
  34. 	}
  35.  
  36. 	return 0;
  37. }
Success #stdin #stdout 0.01s 3472KB
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https://ideone.com/fCjTQs
language:
C++14 (gcc 8.3)
created:
9 years ago
visibility:
public

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