The document discusses comparing bakeries based on their cookies. It describes collecting and sorting cookies from two bakeries into vectors. It then compares the cookies using iterators over the vectors to find differences and return whether the bakeries are equal. Functional programming techniques like using tuples for comparison are also discussed to improve the cookie comparison code.

1. Повседневный С++: boost и STL
Михаил Матросов
mikhail.matrosov@gmail.com
mmatrosov@aligntech.com
1

2. 2

3. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 3

4. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 4
С++17
С++11/14
С++98
С
High level
Expert level
Modern C++

5. “Within C++ is a smaller, simpler, safer
language struggling to get out”
Bjarne Stroustrup
"Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 5

6. High level:
 Парадигма RAII и исключения (exceptions)
 Алгоритмы и контейнеры STL и boost
 Семантика перемещения
 λ-функции
 Классы и конструкторы
 Простые шаблоны
"Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 6
Expert level:
 Операторы new/delete, владеющие
указатели
 Пользовательские операции копирования
и перемещения
 Пользовательские деструкторы
 Закрытое, защищённое, ромбовидное,
виртуальное наследование
 Шаблонная магия, SFINAE
 Все функции языка Си, препроцессор
 «Голые» циклы
Классический слайд с телом и заголовком

7. 7
Which boost
features overlap
with C++11?

8. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 8
bool doCompare(const Bakery* oldBakery, const Bakery* newBakery)
{
if (!oldBakery || !newBakery)
{
return false;
}
std::vector<Cookie> oldCookies;
std::vector<Cookie> newCookies;
std::vector<std::pair<Cookie, int>> diff;
collectCookies(*oldBakery, oldCookies);
collectCookies(*newBakery, newCookies);
std::sort(oldCookies.begin(), oldCookies.end(), compareCookies);
std::sort(newCookies.begin(), newCookies.end(), compareCookies);
auto oldIt = oldCookies.begin();
auto newIt = newCookies.begin();
while ((oldIt != oldCookies.end()) || (newIt != newCookies.end()))

9. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 9
bool doCompare(const Bakery* oldBakery, const Bakery* newBakery)
{
if (!oldBakery || !newBakery)
{
return false;
}
std::vector<Cookie> oldCookies;
std::vector<Cookie> newCookies;
collectCookies(*oldBakery, oldCookies);
collectCookies(*newBakery, newCookies);
std::sort(oldCookies.begin(), oldCookies.end(), compareCookies);
std::sort(newCookies.begin(), newCookies.end(), compareCookies);
auto oldIt = oldCookies.begin();
auto newIt = newCookies.begin();
std::vector<std::pair<Cookie, int>> diff;
while ((oldIt != oldCookies.end()) || (newIt != newCookies.end()))
{
if (compareCookies(*oldIt, *newIt))
{
diff.push_back(std::pair<Cookie, int>(*oldIt, 1));
++oldIt;
}
else if (compareCookies(*newIt, *oldIt))
{
diff.push_back(std::pair<Cookie, int>(*newIt, 2));
++newIt;
}
else
{
++oldIt;
++newIt;
}
}
if (oldIt != oldCookies.end())
{
for (; oldIt < oldCookies.end(); oldIt++)
{
diff.push_back(std::pair<Cookie, int>(*oldIt, 1));
}
}
if (newIt != newCookies.end())
{
for (; newIt < newCookies.end(); newIt++)
{
diff.push_back(std::pair<Cookie, int>(*newIt, 2));
}
}
for (const auto& item : diff)
{
std::cout << "Bakery #" << item.second <<
" has a different cookie "" << item.first.name <<
"" (weight=" << item.first.weight <<
", volume=" << item.first.volume <<
", tastiness=" << item.first.tastiness << ")." << std::endl;
}
if (diff.size() > 0)
return false;
return true;
}
bool doCompare(const Bakery& oldBakery, const Bakery& newBakery)
{
std::vector<Cookie> oldCookies = collectSortedCookies(oldBakery);
std::vector<Cookie> newCookies = collectSortedCookies(newBakery);
std::vector<Cookie> lostCookies;
boost::range::set_difference(oldCookies, newCookies, std::back_inserter(lostCookies));
std::vector<Cookie> appearedCookies;
boost::range::set_difference(newCookies, oldCookies, std::back_inserter(appearedCookies));
for (const auto& cookie : lostCookies)
{
std::cout << "We've lost a friend: " << cookie << "." << std::endl;
}
for (const auto& cookie : appearedCookies)
{
std::cout << "We got a new friend: " << cookie << "." << std::endl;
}
return lostCookies.empty() && appearedCookies.empty();
}

10. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 10
bool doCompare(const Bakery* oldBakery, const Bakery* newBakery)
{
if (!oldBakery || !newBakery)
{
return false;
}
std::vector<Cookie> oldCookies;
std::vector<Cookie> newCookies;
collectCookies(*oldBakery, oldCookies);
collectCookies(*newBakery, newCookies);
// ...

11. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 11
bool doCompare(const Bakery& oldBakery, const Bakery& newBakery)
{
std::vector<Cookie> oldCookies;
std::vector<Cookie> newCookies;
collectCookies(oldBakery, oldCookies);
collectCookies(newBakery, newCookies);
// ...

12. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 12

13. bool doCompare(const Bakery& oldBakery, const Bakery& newBakery)
{
std::vector<Cookie> oldCookies;
std::vector<Cookie> newCookies;
collectCookies(oldBakery, oldCookies);
collectCookies(newBakery, newCookies);
// ...
"Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 13

14. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 14
void collectCookies(const Bakery& bakery, std::vector<Cookie>& o_cookies);
bool doCompare(const Bakery& oldBakery, const Bakery& newBakery)
{
std::vector<Cookie> oldCookies;
std::vector<Cookie> newCookies;
collectCookies(oldBakery, oldCookies);
collectCookies(newBakery, newCookies);
// ...

15. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 15
std::vector<Cookie> collectCookies(const Bakery& bakery);
bool doCompare(const Bakery& oldBakery, const Bakery& newBakery)
{
std::vector<Cookie> oldCookies = collectCookies(oldBakery);
std::vector<Cookie> newCookies = collectCookies(newBakery);
// ...
In-depth: Functional programming in C++

16. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 16
λλ
=:

17. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 17
// ...
std::sort(oldCookies.begin(), oldCookies.end(), compareCookies);
std::sort(newCookies.begin(), newCookies.end(), compareCookies);
auto oldIt = oldCookies.begin();
auto newIt = newCookies.begin();
std::vector<std::pair<Cookie, int>> diff;
while ((oldIt != oldCookies.end()) || (newIt != newCookies.end()))
{
if (compareCookies(*oldIt, *newIt))
{
diff.push_back(std::pair<Cookie, int>(*oldIt, 1));
++oldIt;
}
else if (compareCookies(*newIt, *oldIt))
{
// ...

18. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 18
struct Cookie
{
double weight;
double volume;
std::string name;
int tastiness;
};
bool compareCookies(const Cookie& a, const Cookie& b)
{
if (a.tastiness != b.tastiness)
return a.tastiness < b.tastiness;
if (a.weight != b.weight)
return a.weight < b.weight;
if (a.volume != b.volume)
return a.volume < b.volume;
return a.name < b.name;
}

19. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 19
struct Cookie
{
double weight;
double volume;
std::string name;
int tastiness;
};
bool operator<(const Cookie& a, const Cookie& b)
{
if (a.tastiness != b.tastiness)
return a.tastiness < b.tastiness;
if (a.weight != b.weight)
return a.weight < b.weight;
if (a.volume != b.volume)
return a.volume < b.volume;
return a.name < b.name;
}

20. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 20
// ...
std::sort(oldCookies.begin(), oldCookies.end(), compareCookies);
std::sort(newCookies.begin(), newCookies.end(), compareCookies);
auto oldIt = oldCookies.begin();
auto newIt = newCookies.begin();
while ((oldIt != oldCookies.end()) || (newIt != newCookies.end()))
{
if (compareCookies(*oldIt, *newIt))
{
diff.push_back(std::pair<Cookie, int>(*oldIt, 1));
++oldIt;
}
else if (compareCookies(*newIt, *oldIt))
{
// ...

21. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 21
// ...
std::sort(oldCookies.begin(), oldCookies.end());
std::sort(newCookies.begin(), newCookies.end());
auto oldIt = oldCookies.begin();
auto newIt = newCookies.begin();
while ((oldIt != oldCookies.end()) || (newIt != newCookies.end()))
{
if (*oldIt < *newIt)
{
diff.push_back(std::pair<Cookie, int>(*oldIt, 1));
++oldIt;
}
else if (*newIt < *oldIt)
{
// ...

22. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 22
bool operator<(const Cookie& a, const Cookie& b)
{
if (a.tastiness != b.tastiness)
return a.tastiness < b.tastiness;
if (a.weight != b.weight)
return a.weight < b.weight;
if (a.volume != b.volume)
return a.volume < b.volume;
return a.name < b.name;
}

23. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 23
bool operator<(const Cookie& a, const Cookie& b)
{
return std::make_tuple(a.tastiness, a.weight, a.volume, a.name) <
std::make_tuple(b.tastiness, b.weight, b.volume, b.name);
}

24. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 24
struct Cookie
{
double weight;
double volume;
std::string name;
int tastiness;
};
bool operator<(const Cookie& a, const Cookie& b)
{
return std::make_tuple(a.tastiness, a.weight, a.volume, a.name) <
std::make_tuple(b.tastiness, b.weight, b.volume, b.name);
}

25. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 25
struct Cookie
{
double weight;
double volume;
std::string name;
int tastiness;
};
bool operator<(const Cookie& a, const Cookie& b)
{
return std::tie(a.tastiness, a.weight, a.volume, a.name) <
std::tie(b.tastiness, b.weight, b.volume, b.name);
}

26. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 26
struct Cookie
{
double weight;
double volume;
std::string name;
int tastiness;
auto rank() const
{
return std::tie(tastiness, weight, volume, name);
}
};
bool operator<(const Cookie& a, const Cookie& b)
{
return a.rank() < b.rank();
}
Implementing comparison operators via 'tuple' and 'tie', a good idea?

27. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 27
struct Cookie
{
double weight;
double volume;
std::string name;
int tastiness;
auto rank() const // -> std::tuple<const int&, const double&,
{ // const double&, const std::string&>
return std::tie(tastiness, weight, volume, name);
}
};
bool operator<(const Cookie& a, const Cookie& b)
{
return a.rank() < b.rank();
}
Implementing comparison operators via 'tuple' and 'tie', a good idea?

28. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 28
struct Cookie
{
double weight;
double volume;
std::string name;
int tastiness;
auto rank() const // -> std::tuple<const int&, const double&,
{ // const double&, const std::string&>
return std::tie(tastiness, weight, volume, name);
}
};
bool operator<(const Cookie& a, const Cookie& b)
{
return a.rank() < b.rank();
}
bool operator==(const Cookie& a, const Cookie& b)
{
return a.rank() == b.rank();
}

29. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 29

30. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 30
bool doCompare(const Bakery& oldBakery, const Bakery& newBakery)
{
std::vector<Cookie> oldCookies = collectCookies(oldBakery);
std::vector<Cookie> newCookies = collectCookies(newBakery);
std::sort(oldCookies.begin(), oldCookies.end());
std::sort(newCookies.begin(), newCookies.end());
// ...

31. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 31
std::vector<Cookie> collectCookies(const Bakery& bakery)
{
std::vector<Cookie> cookies;
// ...
// ...
return cookies;
}
bool doCompare(const Bakery& oldBakery, const Bakery& newBakery)
{
std::vector<Cookie> oldCookies = collectCookies(oldBakery);
std::vector<Cookie> newCookies = collectCookies(newBakery);
std::sort(oldCookies.begin(), oldCookies.end());
std::sort(newCookies.begin(), newCookies.end());
// ...

32. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 32
std::vector<Cookie> collectSortedCookies(const Bakery& bakery)
{
std::vector<Cookie> cookies;
// ...
std::sort(cookies.begin(), cookies.end());
return cookies;
}
bool doCompare(const Bakery& oldBakery, const Bakery& newBakery)
{
std::vector<Cookie> oldCookies = collectSortedCookies(oldBakery);
std::vector<Cookie> newCookies = collectSortedCookies(newBakery);
// ...

33. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 33

34. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 34
std::vector<std::pair<Cookie, int>> diff;
// ...
if (*oldIt < *newIt)
{
diff.push_back(std::pair<Cookie, int>(*oldIt, 1));
++oldIt;
}
else if (*newIt < *oldIt)
{
diff.push_back(std::pair<Cookie, int>(*newIt, 2));
++newIt;
}

35. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 35
std::vector<std::pair<Cookie, int>> diff;
// ...
if (*oldIt < *newIt)
{
diff.push_back(std::make_pair(*oldIt, 1));
++oldIt;
}
else if (*newIt < *oldIt)
{
diff.push_back(std::make_pair(*newIt, 2));
++newIt;
}

36. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 36
std::vector<std::pair<Cookie, int>> diff;
// ...
if (*oldIt < *newIt)
{
diff.push_back({ *oldIt, 1 });
++oldIt;
}
else if (*newIt < *oldIt)
{
diff.push_back({ *newIt, 2 });
++newIt;
}

37. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 37
std::vector<std::pair<Cookie, int>> diff;
// ...
if (*oldIt < *newIt)
{
diff.emplace_back(*oldIt, 1);
++oldIt;
}
else if (*newIt < *oldIt)
{
diff.emplace_back(*newIt, 2);
++newIt;
}

38. for (const auto& item : diff) // item is std::pair<Cookie, int>
{
std::cout << "Bakery #" << item.second <<
" has a different cookie "" << item.first.name <<
"" (weight=" << item.first.weight <<
", volume=" << item.first.volume <<
", tastiness=" << item.first.tastiness << ")." << std::endl;
}
"Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 38

39. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 39
for (const auto& item : diff) // item is std::pair<Cookie, int>
{
std::cout << "Bakery #" << item.second <<
" has a different cookie " << item.first << "." << std::endl;
}
std::ostream& operator<<(std::ostream& stream, const Cookie& cookie)
{
return stream << """ << cookie.name <<
"" (weight=" << cookie.weight <<
", volume=" << cookie.volume <<
", tastiness=" << cookie.tastiness << ")";
}

40. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 40
if (diff.size() > 0)
return false;
return true;

41. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 41
return diff.empty();

42. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 42

43. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 43
auto oldIt = oldCookies.begin();
auto newIt = newCookies.begin();
std::vector<std::pair<Cookie, int>> diff;
while ((oldIt != oldCookies.end()) || (newIt != newCookies.end()))
{
if (*oldIt < *newIt)
{
diff.emplace_back(*oldIt, 1);
++oldIt;
}
else if (*newIt < *oldIt)
{
diff.emplace_back(*newIt, 2);
++newIt;
}
else
{
++oldIt;
++newIt;
}
}
for (; oldIt != oldCookies.end(); oldIt++)
{
diff.emplace_back(*oldIt, 1);
}
for (; newIt != newCookies.end(); newIt++)
{
diff.emplace_back(*newIt, 2);
}
1 2 5 7 8 9
1 3 5 6 9
2 7 83 6
oldCookies
newCookies
diff
Ошибка. Должно быть &&
Sean Parent: C++ Seasoning (no raw loops)

44. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 44

45. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 45
std::vector<Cookie> lostCookies;
std::set_difference(oldCookies.begin(), oldCookies.end(),
newCookies.begin(), newCookies.end(),
std::back_inserter(lostCookies));
std::vector<Cookie> appearedCookies;
std::set_difference(newCookies.begin(), newCookies.end(),
oldCookies.begin(), oldCookies.end(),
std::back_inserter(appearedCookies));

46. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 46
std::vector<Cookie> lostCookies;
boost::range::set_difference(oldCookies, newCookies, std::back_inserter(lostCookies));
std::vector<Cookie> appearedCookies;
boost::range::set_difference(newCookies, oldCookies, std::back_inserter(appearedCookies));

47. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 47
std::vector<Cookie> lostCookies;
boost::range::set_difference(oldCookies, newCookies, std::back_inserter(lostCookies));
std::vector<Cookie> appearedCookies;
boost::range::set_difference(newCookies, oldCookies, std::back_inserter(appearedCookies));
for (const auto& cookie : lostCookies)
{
std::cout << "We've lost a friend: " << cookie << "." << std::endl;
}
for (const auto& cookie : appearedCookies)
{
std::cout << "We got a new friend: " << cookie << "." << std::endl;
}

48. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 48
bool doCompare(const Bakery& oldBakery, const Bakery& newBakery)
{
std::vector<Cookie> oldCookies = collectSortedCookies(oldBakery);
std::vector<Cookie> newCookies = collectSortedCookies(newBakery);
return lostCookies.empty() && appearedCookies.empty();
}
std::vector<Cookie> lostCookies;
boost::range::set_difference(oldCookies, newCookies, std::back_inserter(lostCookies));
std::vector<Cookie> appearedCookies;
boost::range::set_difference(newCookies, oldCookies, std::back_inserter(appearedCookies));
for (const auto& cookie : lostCookies)
{
std::cout << "We've lost a friend: " << cookie << "." << std::endl;
}
for (const auto& cookie : appearedCookies)
{
std::cout << "We got a new friend: " << cookie << "." << std::endl;
}

49. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 49
bool doCompare(const Bakery* oldBakery, const Bakery* newBakery)
{
if (!oldBakery || !newBakery)
{
return false;
}
std::vector<Cookie> oldCookies;
std::vector<Cookie> newCookies;
collectCookies(*oldBakery, oldCookies);
collectCookies(*newBakery, newCookies);
std::sort(oldCookies.begin(), oldCookies.end(), compareCookies);
std::sort(newCookies.begin(), newCookies.end(), compareCookies);
auto oldIt = oldCookies.begin();
auto newIt = newCookies.begin();
std::vector<std::pair<Cookie, int>> diff;
while ((oldIt != oldCookies.end()) || (newIt != newCookies.end()))
{
if (compareCookies(*oldIt, *newIt))
{
diff.push_back(std::pair<Cookie, int>(*oldIt, 1));
++oldIt;
}
else if (compareCookies(*newIt, *oldIt))
{
diff.push_back(std::pair<Cookie, int>(*newIt, 2));
++newIt;
}
else
{
++oldIt;
++newIt;
}
}
if (oldIt != oldCookies.end())
{
for (; oldIt < oldCookies.end(); oldIt++)
{
diff.push_back(std::pair<Cookie, int>(*oldIt, 1));
}
}
if (newIt != newCookies.end())
{
for (; newIt < newCookies.end(); newIt++)
{
diff.push_back(std::pair<Cookie, int>(*newIt, 2));
}
}
for (const auto& item : diff)
{
std::cout << "Bakery #" << item.second <<
" has a different cookie "" << item.first.name <<
"" (weight=" << item.first.weight <<
", volume=" << item.first.volume <<
", tastiness=" << item.first.tastiness << ")." << std::endl;
}
if (diff.size() > 0)
return false;
return true;
}
bool doCompare(const Bakery& oldBakery, const Bakery& newBakery)
{
std::vector<Cookie> oldCookies = collectSortedCookies(oldBakery);
std::vector<Cookie> newCookies = collectSortedCookies(newBakery);
std::vector<Cookie> lostCookies;
boost::range::set_difference(oldCookies, newCookies, std::back_inserter(lostCookies));
std::vector<Cookie> appearedCookies;
boost::range::set_difference(newCookies, oldCookies, std::back_inserter(appearedCookies));
for (const auto& cookie : lostCookies)
{
std::cout << "We've lost a friend: " << cookie << "." << std::endl;
}
for (const auto& cookie : appearedCookies)
{
std::cout << "We got a new friend: " << cookie << "." << std::endl;
}
return lostCookies.empty() && appearedCookies.empty();
}

50. Код, использующий стандартные алгоритмы и контейнеры:
 Короче
 Проще
 Надёжнее
 Обычно эффективнее
 Проще переиспользовать
 Не привязан к конкретной платформе
"Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 50

51. И ещё немного
по теме…
"Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 51

52. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 52
struct Cookie
{
double weight;
double volume;
std::string name;
int tastiness;
auto rank() const
{
return std::tie(tastiness, weight, volume, name);
}
};

53. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 53
struct Cookie
{
double weight;
double volume;
std::string name;
int tastiness;
double density() const
{
return weight / volume;
}
auto rank() const
{
return std::tie(tastiness, density(), name);
}
};

54. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 54
struct Cookie
{
double weight;
double volume;
std::string name;
int tastiness;
double density() const
{
return weight / volume;
}
auto rank() const
{
return std::make_tuple(tastiness, density(), std::ref(name));
}
};

55. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 55
struct Cookie
{
double weight;
double volume;
std::string name;
int tastiness;
double density() const
{
return weight / volume;
}
auto rank() const // -> std::tuple<int, double, const std::string&>
{
return std::make_tuple(tastiness, density(), std::ref(name));
}
};

56. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 56
std::vector<Cookie> lostCookies;
boost::range::set_difference(oldCookies, newCookies, std::back_inserter(lostCookies));
std::vector<Cookie> appearedCookies;
boost::range::set_difference(newCookies, oldCookies, std::back_inserter(appearedCookies));
for (const auto& cookie : lostCookies)
{
std::cout << "We've lost a friend: " << cookie << "." << std::endl;
}
for (const auto& cookie : appearedCookies)
{
std::cout << "We got a new friend: " << cookie << "." << std::endl;
}

57. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 57
auto reportLost = [](const Cookie& cookie)
{
std::cout << "We've lost a friend: " << cookie << "." << std::endl;
};
auto reportAppeared = [](const Cookie& cookie)
{
std::cout << "We got a new friend: " << cookie << "." << std::endl;
};
boost::range::set_difference(oldCookies, newCookies,
boost::make_function_output_iterator(reportLost));
boost::range::set_difference(newCookies, oldCookies,
boost::make_function_output_iterator(reportAppeared));

58. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 58
auto reportLost = [](const Cookie& cookie)
{
std::cout << "We've lost a friend: " << cookie << "." << std::endl;
};
auto reportAppeared = [](const Cookie& cookie)
{
std::cout << "We got a new friend: " << cookie << "." << std::endl;
};
boost::range::set_difference(oldCookies, newCookies,
boost::make_function_output_iterator(reportLost));
boost::range::set_difference(newCookies, oldCookies,
boost::make_function_output_iterator(reportAppeared));
return oldCookies == newCookies; // was "lostCookies.empty() && appearedCookies.empty()"

59. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 59
auto f = [](int x) { std::cout << x; };
auto it = boost::make_function_output_iterator(f);
decltype(it) it2 = it; // Ok, copied
it2 = it; // Does not compile, cannot assign!
std::function<void(int)> f = [](int x) { std::cout << x; };
auto it = boost::make_function_output_iterator(f);
decltype(it) it2 = it; // Ok, copied
it2 = it; // Ok, iterator holds an std::function instance
auto f = [](int x) { std::cout << x; };
auto it = boost::make_function_output_iterator(std::ref(f));
decltype(it) it2 = it; // Ok, copied
it2 = it; // Ok, iterator holds a reference
auto f = +[](int x) { std::cout << x; };
auto it = boost::make_function_output_iterator(f);
decltype(it) it2 = it; // Ok, copied
it2 = it; // Ok, note the plus before [], it triggers special C++ magic
Resolving ambiguous overload
on function pointer and
std::function for a lambda using +
boost::function_output_iterator
constructed from lambda
function is not assignable

60. Советы:
 Мыслите на высоком уровне
 Код должен ясно выражать намерение
 Знайте свои инструменты и используйте их к месту
"Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 60
// references
// auto variables
// auto function return type
// move semantics
// lambda functions
operator<();
std::make_tuple();
std::tie();
std::ref();
std::make_pair();
std::vector<T>::emplace_back();
std::vector<T>::empty();
operator<<();
std::back_inserter();
std::set_difference();
boost::range::set_difference();
boost::make_function_output_iterator();
std::function<>

61.  Мыслите на высоком уровне
 Код должен ясно выражать намерение
 Знайте свои инструменты и используйте их к месту
"Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016
std::make_pair();
std::vector<T>::emplace_back();
std::vector<T>::empty();
operator<<();
std::back_inserter();
std::set_difference();
boost::range::set_difference();
boost::make_function_output_iterator();
std::function<>
Спасибо за внимание!
// references
// auto variables
// auto function return type
// move semantics
// lambda functions
operator<();
std::make_tuple();
std::tie();
std::ref();
61

62. "Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 62
compareRanked(Cookie const&, Cookie const&):
movl 16(%rsi), %edx
cmpl %edx, 16(%rdi)
movl $1, %eax
jl .L2
movl $0, %eax
jg .L2
movsd (%rdi), %xmm1
movl $1, %eax
movsd (%rsi), %xmm0
ucomisd %xmm1, %xmm0
ja .L2
xorl %eax, %eax
ucomisd %xmm0, %xmm1
ja .L2
movsd 8(%rsi), %xmm0
ucomisd 8(%rdi), %xmm0
seta %al
.L2:
rep ret
compareDirect(Cookie const&, Cookie const&):
movl 16(%rsi), %eax
cmpl %eax, 16(%rdi)
je .L9
setl %al
ret
.L9:
movsd (%rdi), %xmm0
movsd (%rsi), %xmm1
ucomisd %xmm1, %xmm0
jp .L13
jne .L13
movsd 8(%rsi), %xmm0
ucomisd 8(%rdi), %xmm0
seta %al
ret
.L13:
ucomisd %xmm0, %xmm1
seta %al
ret

63. Ссылки
 Which boost features overlap with C++11?
 In-depth: Functional programming in C++
 Implementing comparison operators via 'tuple' and 'tie', a good idea?
 Sean Parent: C++ Seasoning (no raw loops)
 boost::function_output_iterator constructed from lambda function is not assignable
 Resolving ambiguous overload on function pointer and std::function for a lambda using +
"Повседневный С++: boost и STL", Михаил Матросов, C++ Russia 2016 63