fork download
copy 
  1. #include <bits/stdc++.h>
  2. using namespace std;
  3. using namespace chrono;
  4.  
  5. constexpr int SIZE = 100000;
  6. constexpr int TIMES = 10000;
  7.  
  8. struct Type {
  9. 	int r, g, b;
  10. };
  11.  
  12. int main() {
  13. 	vector<Type> v1( SIZE );
  14. 	vector<Type> v2( v1 );
  15.  
  16. 	for( int i = TIMES; i--; ) {
  17. 		copy( v1.begin(), v1.end(), v2.begin() );
  18. 	}
  19.  
  20. 	auto t2 = steady_clock::now();
  21. 	for( int i = TIMES; i--; ) {
  22. 		copy( v1.begin(), v1.end(), v2.begin() );
  23. 	}
  24. 	cout << "std::copy: ";
  25. 	cout << duration_cast<milliseconds>( steady_clock::now() - t2 ).count() << endl;
  26.  
  27. 	auto t1 = steady_clock::now();
  28. 	for( int i = TIMES; i--; ) {
  29. 		memcpy( v2.data(), v1.data(), v1.size() * sizeof( Type ) );
  30. 	}
  31. 	cout << "memcpy: ";
  32. 	cout << duration_cast<milliseconds>( steady_clock::now() - t1 ).count() << endl;
  33. }
Success #stdin #stdout 1.73s 5040KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
std::copy: 550
memcpy: 548
https://ideone.com/M8sIIk
memcpy vs copy
language:
C++14 (gcc 8.3)
created:
7 years ago
visibility:
public

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