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  1. #include <map>
  2. #include <string>
  3.  
  4. #include <stdio.h>
  5.  
  6. class FOO
  7. {
  8. public:
  9.         FOO() { printf("FOO::FOO()\n"); }
  10.         FOO(const FOO&) { printf("FOO::FOO(const FOO &)\n"); }
  11.         FOO& operator=(const FOO &) { printf("FOO::oprartor=(const FOO&)\n"); return *this; }
  12.         ~FOO() { printf("FOO::~FOO\n"); }
  13.  
  14.         bool operator<(const FOO&) const { return "FOO::operator<(const FOO&)\n"; }
  15.         bool operator>(const FOO&) const { return "FOO::operator>(const FOO&)\n"; }
  16.         bool operator<=(const FOO&) const { return "FOO::operator<=(const FOO&)\n"; }
  17.         bool operator>=(const FOO&) const { return "FOO::operator>=(const FOO&)\n"; }
  18.         bool operator==(const FOO&) const { return "FOO::operator==(const FOO&)\n"; }
  19.         bool operator!=(const FOO&) const { return "FOO::operator!=<(const FOO&)\n"; }
  20. };
  21.  
  22. class BAR
  23. {
  24. public:
  25.         BAR() { printf("BAR::BAR()\n"); }
  26.         BAR(const BAR&) { printf("BAR::BAR(const BAR &)\n"); }
  27.         BAR& operator=(const BAR &) { printf("BAR::oprartor=(const BAR&)\n"); return *this; }
  28.         ~BAR() { printf("BAR::~BAR\n"); }
  29.  
  30.         bool operator<(const BAR&) const { return "BAR::operator<(const BAR&)\n"; }
  31.         bool operator>(const BAR&) const { return "BAR::operator>(const BAR&)\n"; }
  32.         bool operator<=(const BAR&) const { return "BAR::operator<=(const BAR&)\n"; }
  33.         bool operator>=(const BAR&) const { return "BAR::operator>=(const BAR&)\n"; }
  34.         bool operator==(const BAR&) const { return "BAR::operator==(const BAR&)\n"; }
  35.         bool operator!=(const BAR&) const { return "BAR::operator!=<(const BAR&)\n"; }
  36. };
  37.  
  38. int main(void)
  39. {
  40.         typedef std::pair<FOO, BAR> FooBar;
  41.         typedef std::pair<const FOO&, const BAR&> FooBarRef;
  42.  
  43.         std::map<FooBar, int> myMap;
  44.         FOO foo;
  45.         BAR bar;
  46.  
  47.         printf("\nMethod 1:\n");
  48.         myMap.insert(std::make_pair(FooBar(foo, bar), 1));
  49.         printf("Done\n\n");
  50.  
  51.         myMap.clear();
  52.  
  53.         printf("\nMethod 2:\n");
  54.         myMap.insert(std::make_pair(FooBarRef(foo, bar), 1));
  55.         printf("Done\n\n");
  56. }
  57.  
Success #stdin #stdout 0s 2988KB
comments (?)
stdin 
Standard input is empty
stdout 
FOO::FOO()
BAR::BAR()

Method 1:
FOO::FOO(const FOO &)
BAR::BAR(const BAR &)
FOO::FOO(const FOO &)
BAR::BAR(const BAR &)
FOO::FOO(const FOO &)
BAR::BAR(const BAR &)
FOO::FOO(const FOO &)
BAR::BAR(const BAR &)
BAR::~BAR
FOO::~FOO
BAR::~BAR
FOO::~FOO
BAR::~BAR
FOO::~FOO
Done

BAR::~BAR
FOO::~FOO

Method 2:
FOO::FOO(const FOO &)
BAR::BAR(const BAR &)
FOO::FOO(const FOO &)
BAR::BAR(const BAR &)
BAR::~BAR
FOO::~FOO
Done

BAR::~BAR
FOO::~FOO
BAR::~BAR
FOO::~FOO
https://ideone.com/QggSh9
language:
C++ (gcc 8.3)
created:
12 years ago
visibility:
secret

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