fork download
copy 
  1. #include <iostream>
  2. #include <vector>
  3. #include <memory>
  4. #include <algorithm>
  5. using namespace std;
  6.  
  7. class Story
  8. {
  9.     int n;
  10. public:
  11.     Story(int n): n(n) { cout << "story #" << n << " created" << endl; }
  12.     ~Story() { cout << "story #" << n << " destroyed" << endl; }
  13.     void print() { cout << "story #" << n << " reporting" << endl; }
  14. };
  15.  
  16. int main()
  17. {
  18.     vector<shared_ptr<Story>> main_list;
  19.     vector<weak_ptr<Story>> aux_list;
  20.  
  21.     cout << "creating and adding to owning list" << endl;
  22.     main_list.emplace_back(make_shared<Story>(1));
  23.     main_list.emplace_back(make_shared<Story>(2));
  24.     cout << "copying to non-owning list" << endl;
  25.     aux_list.push_back(main_list[0]);
  26.     aux_list.push_back(main_list[1]);
  27.     cout << "removing #2" << endl;
  28.     main_list.resize(1);
  29.     for (auto& weakptr : aux_list)
  30.     {
  31.     	if (auto strongptr = weakptr.lock())
  32.     	    strongptr->print();
  33.     	else
  34.     	    cout << "(deleted entry)" << endl;
  35.     }
  36.     cout << "cleaning non-owning list" << endl;
  37.     aux_list.erase(
  38.     	remove_if(begin(aux_list), end(aux_list), [](auto wp) { return wp.expired(); }),
  39.     	end(aux_list));
  40.     for (auto& weakptr : aux_list)
  41.     {
  42.     	if (auto strongptr = weakptr.lock())
  43.     	    strongptr->print();
  44.     	else
  45.     	    cout << "(cannot happen)" << endl;
  46.     }
  47.     cout << "done" << endl;
  48. }
Success #stdin #stdout 0s 3468KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
creating and adding to owning list
story #1 created
story #2 created
copying to non-owning list
removing #2
story #2 destroyed
story #1 reporting
(deleted entry)
cleaning non-owning list
story #1 reporting
done
story #1 destroyed
https://ideone.com/WPVuhB
language:
C++14 (gcc 8.3)
created:
7 years ago
visibility:
public

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!