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  1. // http://stackoverflow.com/questions/14917169/finding-an-element-in-a-shared-ptr-container/14917562#14917562
  2.  
  3. #include <vector>
  4. #include <memory>
  5. #include <algorithm>
  6. #include <iostream>
  7.  
  8. using namespace std;
  9.  
  10. struct Block
  11. {
  12.     bool in_container(const vector<shared_ptr<Block>>& blocks)
  13.     {
  14.         auto end = blocks.end();
  15.         return end != find_if(blocks.begin(), end,
  16.                               [this](shared_ptr<Block> const& i)
  17.                                   { return i.get() == this; });
  18.     }
  19. };
  20.  
  21. int main()
  22. {
  23.     auto block1 = make_shared<Block>();
  24.     auto block2 = make_shared<Block>();
  25.  
  26.     vector<shared_ptr<Block>> blocks;
  27.     blocks.push_back(block1);
  28.  
  29.     block1->in_container(blocks) ?
  30.         cout << "block1 is in the container\n" :
  31.         cout << "block1 is not in the container\n";
  32.  
  33.     block2->in_container(blocks) ?
  34.         cout << "block2 is in the container\n" :
  35.         cout << "block2 is not in the container\n";
  36.  
  37.     return 0;
  38. }
Success #stdin #stdout 0s 2988KB
comments (?)
stdin 
Standard input is empty
stdout 
block1 is in the container
block2 is not in the container
https://ideone.com/Ve9EqA
language:
C++14 (gcc 8.3)
created:
11 years ago
visibility:
public

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