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  1. #include <climits>
  2. #include <cmath>
  3. #include <bitset>
  4. #include <iostream>
  5.  
  6. template <typename T>
  7. T build_mask(T num) {
  8. 	const int up_to_bit = log2(num);
  9. 	for (int i = 0; i < up_to_bit; i++)
  10. 		num |= 1 << i;
  11. 	return num;
  12. }
  13.  
  14. template <typename T>
  15. std::bitset<sizeof(T) * CHAR_BIT> get_bits(T num) {
  16. 	return std::bitset<sizeof(T) * CHAR_BIT>(num);
  17. }
  18.  
  19. int main() {
  20. 	int32_t msk = 9;
  21. 	int32_t nMsk = ~msk & build_mask(msk);
  22.  
  23. 	std::cout << "value: " << msk << std::endl;
  24. 	std::cout << "bits : " << get_bits(msk) << std::endl;
  25. 	std::cout << "mask : " << get_bits(build_mask(msk)) << std::endl;
  26.  
  27. 	std::cout << "value: " << nMsk << std::endl;
  28. 	std::cout << "bits : " << get_bits(nMsk) << std::endl;
  29.  
  30. 	return 0;
  31. }
  32.  
Success #stdin #stdout 0s 3464KB
comments (?)
stdin 
Standard input is empty
stdout 
value: 9
bits : 00000000000000000000000000001001
mask : 00000000000000000000000000001111
value: 6
bits : 00000000000000000000000000000110
https://ideone.com/aC7CQT
language:
C++14 (gcc 8.3)
created:
9 years ago
visibility:
public

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