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  1. #include <set>
  2. #include <chrono>
  3. #include <iostream>
  4.  
  5. using Time = std::chrono::high_resolution_clock;
  6. using ms = std::chrono::milliseconds;
  7.  
  8. int main()
  9. {
  10.     std::set<int> initialSet;
  11.     for (int i = 0; i < 5000000; ++i) {
  12.         initialSet.insert(i);
  13.     }
  14.  
  15.     std::set<int> setFilledWithForInsert;
  16.     {
  17.         const auto start = Time::now();
  18.         for (const int value: initialSet) {
  19.             setFilledWithForInsert.insert(value);
  20.         }
  21.         std::cout << "Insert: " << std::chrono::duration_cast<ms>(Time::now() - start).count() << "\n";
  22.     }
  23.  
  24.     std::set<int> setFilledWithForEmplaceHint;
  25.     {
  26.         const auto start = Time::now();
  27.         auto it = setFilledWithForEmplaceHint.cend();
  28.         for (const int value: initialSet) {
  29.             it = setFilledWithForEmplaceHint.emplace_hint(it, value);
  30.         }
  31.         std::cout << "EmplaceHint: " << std::chrono::duration_cast<ms>(Time::now() - start).count() << "\n";
  32.     }
  33.  
  34.     std::set<int> setFilledWithForInsertHint;
  35.     {
  36.         const auto start = std::chrono::system_clock::now();
  37.         auto it = setFilledWithForEmplaceHint.cend();
  38.         for (const int value: initialSet) {
  39.             it = setFilledWithForInsertHint.insert(it, value);
  40.         }
  41.         std::cout << "InsertHint: " << std::chrono::duration_cast<ms>(Time::now() - start).count() << "\n";
  42.     }
  43.  
  44.     std::set<int> setFilledWithIterators;
  45.     {
  46.         const auto start = std::chrono::system_clock::now();
  47.         setFilledWithIterators.insert(initialSet.cbegin(), initialSet.cend());
  48.         std::cout << "InsertIterators: " <<  std::chrono::duration_cast<ms>(Time::now() - start).count() << "\n";
  49.     }
  50.  
  51.     return 0;
  52. }
  53.  
Success #stdin #stdout 3.47s 1187328KB
comments (?)
stdin 
Standard input is empty
stdout 
Insert: 1065
EmplaceHint: 256
InsertHint: 281
InsertIterators: 273
https://ideone.com/tGvhpt
language:
C++ (gcc 8.3)
created:
7 years ago
visibility:
public

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