제출 #457720

#제출 시각아이디문제언어결과실행 시간메모리
457720zeyuBitaro’s Party (JOI18_bitaro)C++17
컴파일 에러
0 ms0 KiB
#include <bits/stdc++.h> #define set unordered_set #define maxn 100010 using namespace std; const int B = 320; int n, m, q; typedef pair<int, int> pi; vector<int> prv[maxn]; set<pi> top[maxn]; set<pi> pot[maxn]; void add(pi p, int i){ set<pi>::iterator q = pot[i].lower_bound(make_pair(p.second, 0)); if (q != pot[i].end() && q -> first == p.second){ p = max(p, make_pair(q -> second, q -> first)); pot[i].erase(q); pot[i].insert(make_pair(p.second, p.first)); top[i].erase(make_pair(q -> second, q -> first)); top[i].insert(p); } else{ if (top[i].size() < B){ top[i].insert(p); pot[i].insert(make_pair(p.second, p.first)); } else{ if (top[i].begin() -> first < p.first){ top[i].erase(top[i].begin()); top[i].insert(p); pot[i].insert(make_pair(p.second, p.first)); } } } } int main(){ ios::sync_with_stdio(false); cin.tie(0); cin >> n >> m >> q; for (int i = 0; i < m; i ++){ int x, y; cin >> x >> y; x --; y --; prv[y].push_back(x); } for (int i = 0; i < n; i ++){ top[i].insert(make_pair(0, i)); pot[i].insert(make_pair(i, 0)); } for (int i = 0; i < n; i ++){ for (int j = 0; j < (int)prv[i].size(); j ++){ int x = prv[i][j]; for (set<pi>::iterator it = top[x].begin(); it != top[x].end(); it ++){ add(make_pair(it -> first + 1, it -> second), i); } add(make_pair(1, x), i); } } while(q --){ int t; cin >> t; t --; int r; cin >> r; set<int> y; for (int i = 0; i < r; i ++){ int p; cin >> p; p --; y.insert(p); } if (r >= B){ vector<int> dp(n, -1); for (int i = 0; i <= t; i ++){ if (y.find(i) == y.end()){ dp[i] = max(dp[i], 0); } for (int j = 0; j < (int)prv[i].size(); j ++){ if (dp[prv[i][j]] != -1) dp[i] = max(dp[i], dp[prv[i][j]] + 1); } } cout << dp[t] << '\n'; } else{ for (set<pi>::reverse_iterator it = top[t].rbegin(); it != top[t].rend(); it ++){ if (y.find(it -> second) == y.end()){ cout << it -> first << '\n'; goto done; } } cout << -1 << '\n'; done: continue; } } }

컴파일 시 표준 에러 (stderr) 메시지

bitaro.cpp:9:17: error: use of deleted function 'std::unordered_set<_Value, _Hash, _Pred, _Alloc>::unordered_set() [with _Value = std::pair<int, int>; _Hash = std::hash<std::pair<int, int> >; _Pred = std::equal_to<std::pair<int, int> >; _Alloc = std::allocator<std::pair<int, int> >]'
    9 | set<pi> top[maxn];
      |                 ^
In file included from /usr/include/c++/10/unordered_set:47,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:118,
                 from bitaro.cpp:1:
/usr/include/c++/10/bits/unordered_set.h:135:7: note: 'std::unordered_set<_Value, _Hash, _Pred, _Alloc>::unordered_set() [with _Value = std::pair<int, int>; _Hash = std::hash<std::pair<int, int> >; _Pred = std::equal_to<std::pair<int, int> >; _Alloc = std::allocator<std::pair<int, int> >]' is implicitly deleted because the default definition would be ill-formed:
  135 |       unordered_set() = default;
      |       ^~~~~~~~~~~~~
/usr/include/c++/10/bits/unordered_set.h:135:7: error: use of deleted function 'std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::_Hashtable() [with _Key = std::pair<int, int>; _Value = std::pair<int, int>; _Alloc = std::allocator<std::pair<int, int> >; _ExtractKey = std::__detail::_Identity; _Equal = std::equal_to<std::pair<int, int> >; _H1 = std::hash<std::pair<int, int> >; _H2 = std::__detail::_Mod_range_hashing; _Hash = std::__detail::_Default_ranged_hash; _RehashPolicy = std::__detail::_Prime_rehash_policy; _Traits = std::__detail::_Hashtable_traits<true, true, true>]'
In file included from /usr/include/c++/10/unordered_map:46,
                 from /usr/include/c++/10/functional:61,
                 from /usr/include/c++/10/pstl/glue_algorithm_defs.h:13,
                 from /usr/include/c++/10/algorithm:74,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:65,
                 from bitaro.cpp:1:
/usr/include/c++/10/bits/hashtable.h:451:7: note: 'std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::_Hashtable() [with _Key = std::pair<int, int>; _Value = std::pair<int, int>; _Alloc = std::allocator<std::pair<int, int> >; _ExtractKey = std::__detail::_Identity; _Equal = std::equal_to<std::pair<int, int> >; _H1 = std::hash<std::pair<int, int> >; _H2 = std::__detail::_Mod_range_hashing; _Hash = std::__detail::_Default_ranged_hash; _RehashPolicy = std::__detail::_Prime_rehash_policy; _Traits = std::__detail::_Hashtable_traits<true, true, true>]' is implicitly deleted because the default definition would be ill-formed:
  451 |       _Hashtable() = default;
      |       ^~~~~~~~~~
/usr/include/c++/10/bits/hashtable.h:451:7: error: use of deleted function 'std::__detail::_Hashtable_base<_Key, _Value, _ExtractKey, _Equal, _H1, _H2, _Hash, _Traits>::_Hashtable_base() [with _Key = std::pair<int, int>; _Value = std::pair<int, int>; _ExtractKey = std::__detail::_Identity; _Equal = std::equal_to<std::pair<int, int> >; _H1 = std::hash<std::pair<int, int> >; _H2 = std::__detail::_Mod_range_hashing; _Hash = std::__detail::_Default_ranged_hash; _Traits = std::__detail::_Hashtable_traits<true, true, true>]'
In file included from /usr/include/c++/10/bits/hashtable.h:35,
                 from /usr/include/c++/10/unordered_map:46,
                 from /usr/include/c++/10/functional:61,
                 from /usr/include/c++/10/pstl/glue_algorithm_defs.h:13,
                 from /usr/include/c++/10/algorithm:74,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:65,
                 from bitaro.cpp:1:
/usr/include/c++/10/bits/hashtable_policy.h:1791:5: note: 'std::__detail::_Hashtable_base<_Key, _Value, _ExtractKey, _Equal, _H1, _H2, _Hash, _Traits>::_Hashtable_base() [with _Key = std::pair<int, int>; _Value = std::pair<int, int>; _ExtractKey = std::__detail::_Identity; _Equal = std::equal_to<std::pair<int, int> >; _H1 = std::hash<std::pair<int, int> >; _H2 = std::__detail::_Mod_range_hashing; _Hash = std::__detail::_Default_ranged_hash; _Traits = std::__detail::_Hashtable_traits<true, true, true>]' is implicitly deleted because the default definition would be ill-formed:
 1791 |     _Hashtable_base() = default;
      |     ^~~~~~~~~~~~~~~
/usr/include/c++/10/bits/hashtable_policy.h:1791:5: error: use of deleted function 'std::__detail::_Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, std::__detail::_Default_ranged_hash, true>::_Hash_code_base() [with _Key = std::pair<int, int>; _Value = std::pair<int, int>; _ExtractKey = std::__detail::_Identity; _H1 = std::hash<std::pair<int, int> >; _H2 = std::__detail::_Mod_range_hashing]'
/usr/include/c++/10/bits/hashtable_policy.h:1368:7: note: 'std::__detail::_Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, std::__detail::_Default_ranged_hash, true>::_Hash_code_base() [with _Key = std::pair<int, int>; _Value = std::pair<int, int>; _ExtractKey = std::__detail::_Identity; _H1 = std::hash<std::pair<int, int> >; _H2 = std::__detail::_Mod_range_hashing]' is implicitly deleted because the default definition would be ill-formed:
 1368 |       _Hash_code_base() = default;
      |       ^~~~~~~~~~~~~~~
/usr/include/c++/10/bits/hashtable_policy.h:1368:7: error: use of deleted function 'std::__detail::_Hashtable_ebo_helper<_Nm, _Tp, true>::_Hashtable_ebo_helper() [with int _Nm = 1; _Tp = std::hash<std::pair<int, int> >]'
/usr/include/c++/10/bits/hashtable_policy.h:1112:7: note: 'std::__detail::_Hashtable_ebo_helper<_Nm, _Tp, true>::_Hashtable_ebo_helper() [with int _Nm = 1; _Tp = std::hash<std::pair<int, int> >]' is implicitly deleted because the default definition would be ill-formed:
 1112 |       _Hashtable_ebo_helper() = default;
      |       ^~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/10/bits/hashtable_policy.h:1112:7: error: use of deleted function 'std::hash<std::pair<int, int> >::hash()'
In file included from /usr/include/c++/10/string_view:42,
                 from /usr/include/c++/10/bits/basic_string.h:48,
                 from /usr/include/c++/10/string:55,
                 from /usr/include/c++/10/bits/locale_classes.h:40,
                 from /usr/include/c++/10/bits/ios_base.h:41,
                 from /usr/include/c++/10/ios:42,
                 from /usr/include/c++/10/istream:38,
                 from /usr/include/c++/10/sstream:38,
                 from /usr/include/c++/10/complex:45,
                 from /usr/include/c++/10/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:54,
                 from bitaro.cpp:1:
/usr/include/c++/10/bits/functional_hash.h:101:12: note: 'std::hash<std::pair<int, int> >::hash()' is implicitly deleted because the default definition would be ill-formed:
  101 |     struct hash : __hash_enum<_Tp>
      |            ^~~~
/usr/include/c++/10/bits/functional_hash.h:101:12: error: no matching function for call to 'std::__hash_enum<std::pair<int, int>, false>::__hash_enum()'
/usr/include/c++/10/bits/functional_hash.h:82:7: note: candidate: 'std::__hash_enum<_Tp, <anonymous> >::__hash_enum(std::__hash_enum<_Tp, <anonymous> >&&) [with _Tp = std::pair<int, int>; bool <anonymous> = false]'
   82 |       __hash_enum(__hash_enum&&);
      |       ^~~~~~~~~~~
/usr/include/c++/10/bits/functional_hash.h:82:7: note:   candidate expects 1 argument, 0 provided
/usr/include/c++/10/bits/functional_hash.h:101:12: error: 'std::__hash_enum<_Tp, <anonymous> >::~__hash_enum() [with _Tp = std::pair<int, int>; bool <anonymous> = false]' is private within this context
  101 |     struct hash : __hash_enum<_Tp>
      |            ^~~~
/usr/include/c++/10/bits/functional_hash.h:83:7: note: declared private here
   83 |       ~__hash_enum();
      |       ^
In file included from /usr/include/c++/10/bits/hashtable.h:35,
                 from /usr/include/c++/10/unordered_map:46,
                 from /usr/include/c++/10/functional:61,
                 from /usr/include/c++/10/pstl/glue_algorithm_defs.h:13,
                 from /usr/include/c++/10/algorithm:74,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:65,
                 from bitaro.cpp:1:
/usr/include/c++/10/bits/hashtable_policy.h:1112:7: error: use of deleted function 'std::hash<std::pair<int, int> >::~hash()'
 1112 |       _Hashtable_ebo_helper() = default;
      |       ^~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/10/string_view:42,
                 from /usr/include/c++/10/bits/basic_string.h:48,
                 from /usr/include/c++/10/string:55,
                 from /usr/include/c++/10/bits/locale_classes.h:40,
                 from /usr/include/c++/10/bits/ios_base.h:41,
                 from /usr/include/c++/10/ios:42,
                 from /usr/include/c++/10/istream:38,
                 from /usr/include/c++/10/sstream:38,
                 from /usr/include/c++/10/complex:45,
                 from /usr/include/c++/10/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:54,
                 from bitaro.cpp:1:
/usr/include/c++/10/bits/functional_hash.h:101:12: note: 'std::hash<std::pair<int, int> >::~hash()' is implicitly deleted because the default definition would be ill-formed:
  101 |     struct hash : __hash_enum<_Tp>
      |            ^~~~
/usr/include/c++/10/bits/functional_hash.h:101:12: error: 'std::__hash_enum<_Tp, <anonymous> >::~__hash_enum() [with _Tp = std::pair<int, int>; bool <anonymous> = false]' is private within this context
/usr/include/c++/10/bits/functional_hash.h:83:7: note: declared private here
   83 |       ~__hash_enum();
      |       ^
In file included from /usr/include/c++/10/bits/hashtable.h:35,
                 from /usr/include/c++/10/unordered_map:46,
                 from /usr/include/c++/10/functional:61,
                 from /usr/include/c++/10/pstl/glue_algorithm_defs.h:13,
                 from /usr/include/c++/10/algorithm:74,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:65,
                 from bitaro.cpp:1:
/usr/include/c++/10/bits/hashtable_policy.h:1368:7: error: use of deleted function 'std::__detail::_Hashtable_ebo_helper<1, std::hash<std::pair<int, int> >, true>::~_Hashtable_ebo_helper()'
 1368 |       _Hash_code_base() = default;
      |       ^~~~~~~~~~~~~~~
/usr/include/c++/10/bits/hashtable_policy.h:1109:12: note: 'std::__detail::_Hashtable_ebo_helper<1, std::hash<std::pair<int, int> >, true>::~_Hashtable_ebo_helper()' is implicitly deleted because the default definition would be ill-formed:
 1109 |     struct _Hashtable_ebo_helper<_Nm, _Tp, true>
      |            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/10/bits/hashtable_policy.h:1109:12: error: use of deleted function 'std::hash<std::pair<int, int> >::~hash()'
/usr/include/c++/10/bits/hashtable_policy.h:1791:5: error: use of deleted function 'std::__detail::_Hash_code_base<std::pair<int, int>, std::pair<int, int>, std::__detail::_Identity, std::hash<std::pair<int, int> >, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, true>::~_Hash_code_base()'
 1791 |     _Hashtable_base() = default;
      |     ^~~~~~~~~~~~~~~
/usr/include/c++/10/bits/hashtable_policy.h:1341:12: note: 'std::__detail::_Hash_code_base<std::pair<int, int>, std::pair<int, int>, std::__detail::_Identity, std::hash<std::pair<int, int> >, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, true>::~_Hash_code_base()' is implicitly deleted because the default definition would be ill-formed:
 1341 |     struct _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2,
      |            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 1342 |       _Default_ranged_hash, true>
      |       ~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/10/bits/hashtable_policy.h:1341:12: error: use of deleted function 'std::__detail::_Hashtable_ebo_helper<1, std::hash<std::pair<int, int> >, true>::~_Hashtable_ebo_helper()'
In file included from /usr/include/c++/10/unordered_map:46,
                 from /usr/include/c++/10/functional:61,
                 from /usr/include/c++/10/pstl/glue_algorithm_defs.h:13,
                 from /usr/include/c++/10/algorithm:74,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:65,
                 from bitaro.cpp:1:
/usr/include/c++/10/bits/hashtable.h:451:7: error: use of deleted function 'std::__detail::_Hashtable_base<std::pair<int, int>, std::pair<int, int>, std::__detail::_Identity, std::equal_to<std::pair<int, int> >, std::hash<std::pair<int, int> >, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Hashtable_traits<true, true, true> >::~_Hashtable_base()'
  451 |       _Hashtable() = default;
      |       ^~~~~~~~~~
In file included from /usr/include/c++/10/bits/hashtable.h:35,
                 from /usr/include/c++/10/unordered_map:46,
                 from /usr/include/c++/10/functional:61,
                 from /usr/include/c++/10/pstl/glue_algorithm_defs.h:13,
                 from /usr/include/c++/10/algorithm:74,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:65,
                 from bitaro.cpp:1:
/usr/include/c++/10/bits/hashtable_policy.h:1725:10: note: 'std::__detail::_Hashtable_base<std::pair<int, int>, std::pair<int, int>, std::__detail::_Identity, std::equal_to<std::pair<int, int> >, std::hash<std::pair<int, int> >, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Hashtable_traits<true, true, true> >::~_Hashtable_base()' is implicitly deleted because the default definition would be ill-formed:
 1725 |   struct _Hashtable_base
      |          ^~~~~~~~~~~~~~~
/usr/include/c++/10/bits/hashtable_policy.h:1725:10: error: use of deleted function 'std::__detail::_Hash_code_base<std::pair<int, int>, std::pair<int, int>, std::__detail::_Identity, std::hash<std::pair<int, int> >, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, true>::~_Hash_code_base()'
bitaro.cpp:10:17: error: use of deleted function 'std::unordered_set<_Value, _Hash, _Pred, _Alloc>::unordered_set() [with _Value = std::pair<int, int>; _Hash = std::hash<std::pair<int, int> >; _Pred = std::equal_to<std::pair<int, int> >; _Alloc = std::allocator<std::pair<int, int> >]'
   10 | set<pi> pot[maxn];
      |                 ^
bitaro.cpp: In function 'void add(pi, int)':
bitaro.cpp:13:31: error: 'class std::unordered_set<std::pair<int, int> >' has no member named 'lower_bound'
   13 |  set<pi>::iterator q = pot[i].lower_bound(make_pair(p.second, 0));
      |                               ^~~~~~~~~~~
bitaro.cpp: In function 'int main()':
bitaro.cpp:77:18: error: 'reverse_iterator' is not a member of 'std::unordered_set<std::pair<int, int> >'
   77 |    for (set<pi>::reverse_iterator it = top[t].rbegin(); it != top[t].rend(); it ++){
      |                  ^~~~~~~~~~~~~~~~
bitaro.cpp:77:57: error: 'it' was not declared in this scope; did you mean 't'?
   77 |    for (set<pi>::reverse_iterator it = top[t].rbegin(); it != top[t].rend(); it ++){
      |                                                         ^~
      |                                                         t
bitaro.cpp:77:70: error: 'class std::unordered_set<std::pair<int, int> >' has no member named 'rend'; did you mean 'end'?
   77 |    for (set<pi>::reverse_iterator it = top[t].rbegin(); it != top[t].rend(); it ++){
      |                                                                      ^~~~
      |                                                                      end
In file included from /usr/include/c++/10/unordered_map:46,
                 from /usr/include/c++/10/functional:61,
                 from /usr/include/c++/10/pstl/glue_algorithm_defs.h:13,
                 from /usr/include/c++/10/algorithm:74,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:65,
                 from bitaro.cpp:1:
/usr/include/c++/10/bits/hashtable.h: In instantiation of 'std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::~_Hashtable() [with _Key = std::pair<int, int>; _Value = std::pair<int, int>; _Alloc = std::allocator<std::pair<int, int> >; _ExtractKey = std::__detail::_Identity; _Equal = std::equal_to<std::pair<int, int> >; _H1 = std::hash<std::pair<int, int> >; _H2 = std::__detail::_Mod_range_hashing; _Hash = std::__detail::_Default_ranged_hash; _RehashPolicy = std::__detail::_Prime_rehash_policy; _Traits = std::__detail::_Hashtable_traits<true, true, true>]':
/usr/include/c++/10/bits/unordered_set.h:97:11:   required from here
/usr/include/c++/10/bits/hashtable.h:1389:5: error: use of deleted function 'std::__detail::_Hashtable_base<std::pair<int, int>, std::pair<int, int>, std::__detail::_Identity, std::equal_to<std::pair<int, int> >, std::hash<std::pair<int, int> >, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Hashtable_traits<true, true, true> >::~_Hashtable_base()'
 1389 |     }
      |     ^
In file included from /usr/include/c++/10/bits/hashtable.h:35,
                 from /usr/include/c++/10/unordered_map:46,
                 from /usr/include/c++/10/functional:61,
                 from /usr/include/c++/10/pstl/glue_algorithm_defs.h:13,
                 from /usr/include/c++/10/algorithm:74,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:65,
                 from bitaro.cpp:1:
/usr/include/c++/10/bits/hashtable_policy.h: In instantiation of 'std::__detail::_Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, std::__detail::_Default_ranged_hash, true>::__hash_code std::__detail::_Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, std::__detail::_Default_ranged_hash, true>::_M_hash_code(const _Key&) const [with _Key = std::pair<int, int>; _Value = std::pair<int, int>; _ExtractKey = std::__detail::_Identity; _H1 = std::hash<std::pair<int, int> >; _H2 = std::__detail::_Mod_range_hashing; std::__detail::_Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, std::__detail::_Default_ranged_hash, true>::__hash_code = long unsigned int]':
/usr/include/c++/10/bits/hashtable.h:1807:41:   required from 'std::pair<typename std::__detail::_Hashtable_base<_Key, _Value, _ExtractKey, _Equal, _H1, _H2, _Hash, _Traits>::iterator, bool> std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::_M_insert(_Arg&&, const _NodeGenerator&, std::true_type, std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, _RehashPolicy, _Traits>::size_type) [with _Arg = std::pair<int, int>; _NodeGenerator = std::__detail::_AllocNode<std::allocator<std::__detail::_Hash_node<std::pair<int, int>, true> > >; _Key = std::pair<int, int>; _Value = std::pair<int, int>; _Alloc = std::allocator<std::pair<int, int> >; _ExtractKey = std::__detail::_Identity; _Equal = std::equal_to<std::pair<int, int> >; _H1 = std::hash<std::pair<int, int> >; _H2 = std::__detail::_Mod_range_hashing; _Hash = std::__detail::_Default_ranged_hash; _RehashPolicy = std::__detail::_Prime_rehash_policy; _Traits = std::__detail::_Hashtable_traits<true, true, true>; typename std::__detail::_Hashtable_base<_Key, _Value, _ExtractKey, _Equal, _H1, _H2, _Hash, _Traits>::iterator = std::__detail::_Hashtable_base<std::pair<int, int>, std::pair<int, int>, std::__detail::_Identity, std::equal_to