fork(1) download
copy 
  1. #include <iostream>
  2. #include <ctime>
  3. #include <vector>
  4.  
  5. using namespace std;
  6.  
  7. struct A {
  8.     virtual void foo() {}
  9. };
  10.  
  11. struct B : public A {
  12.     virtual void foo() override {}
  13. };
  14.  
  15. struct C : public B {
  16.     virtual void foo() override {}
  17. };
  18.  
  19. int main()
  20. {
  21.     vector<A *> vec;
  22.     for (int i = 0; i < 10000000; ++i)
  23.         if (i % 2)
  24.             vec.push_back(new C());
  25.         else
  26.             vec.push_back(new B());
  27.  
  28.     clock_t begin = clock();
  29.     for (auto iter : vec)
  30.     {
  31.         if (C* cptr = dynamic_cast<C*>(iter))
  32.         {
  33.             cptr->foo();
  34.         }
  35.         if (B* bptr = dynamic_cast<B*>(iter))
  36.         {
  37.             bptr->foo();
  38.         }
  39.     }
  40.     clock_t end = clock();
  41.     cout << (static_cast<double>(end) - begin) / CLOCKS_PER_SEC << endl;
  42.  
  43.     begin = clock();
  44.     for (auto iter : vec)
  45.         iter->foo();
  46.     end = clock();
  47.  
  48.     cout << (static_cast<double>(end) - begin) / CLOCKS_PER_SEC << endl;
  49.  
  50.     return 0;
  51. }
  52.  
Success #stdin #stdout 0.58s 328384KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
0.229774
0.028346
https://ideone.com/BvqoqU
language:
C++14 (gcc 8.3)
created:
7 years ago
visibility:
secret

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!