Eroare de compilare: In file included from /usr/include/c++/6/bits/hashtable.h:35:0, from /usr/include/c++/6/unordered_set:47, from main.cpp:3: /usr/include/c++/6/bits/hashtable_policy.h: In instantiation of 'struct std::__detail::__is_noexcept_hash<int, pair_hash>': /usr/include/c++/6/type_traits:143:12: required from 'struct std::__and_<std::__is_fast_hash<pair_hash>, std::__detail::__is_noexcept_hash<int, pair_hash> >' /usr/include/c++/6/type_traits:154:38: required from 'struct std::__not_<std::__and_<std::__is_fast_hash<pair_hash>, std::__detail::__is_noexcept_hash<int, pair_hash> > >' /usr/include/c++/6/bits/unordered_set.h:95:63: required from 'class std::unordered_set<int, pair_hash>' main.cpp:16:39: required from here /usr/include/c++/6/bits/hashtable_policy.h:85:34: error: no match for call to '(const pair_hash) (const int&)' noexcept(declval<const _Hash&>()(declval<const _Key&>()))> ~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~ main.cpp:11:24: note: candidate: std::size_t pair_hash::operator()(const std::pair<int, int>&) const inline std::size_t operator()(const std::pair<int, int>& v) const { ^~~~~~~~ main.cpp:11:24: note: no known conversion for argument 1 from 'const int' to 'const std::pair<int, int>&' In file included from /usr/include/c++/6/bits/move.h:57:0, from /usr/include/c++/6/bits/nested_exception.h:40, from /usr/include/c++/6/exception:171, from /usr/include/c++/6/ios:39, from /usr/include/c++/6/istream:38, from /usr/include/c++/6/fstream:38, from main.cpp:1: /usr/include/c++/6/type_traits: In instantiation of 'struct std::__not_<std::__and_<std::__is_fast_hash<pair_hash>, std::__detail::__is_noexcept_hash<int, pair_hash> > >': /usr/include/c++/6/bits/unordered_set.h:95:63: required from 'class std::unordered_set<int, pair_hash>' main.cpp:16:39: required from here /usr/include/c++/6/type_traits:154:38: error: 'value' is not a member of 'std::__and_<std::__is_fast_hash<pair_hash>, std::__detail::__is_noexcept_hash<int, pair_hash> >' : public integral_constant<bool, !_Pp::value> ^~~~ In file included from /usr/include/c++/6/unordered_set:48:0, from main.cpp:3: /usr/include/c++/6/bits/unordered_set.h: In instantiation of 'class std::unordered_set<int, pair_hash>': main.cpp:16:39: required from here /usr/include/c++/6/bits/unordered_set.h:95:63: error: 'value' is not a member of 'std::__not_<std::__and_<std::__is_fast_hash<pair_hash>, std::__detail::__is_noexcept_hash<int, pair_hash> > >' typedef __uset_hashtable<_Value, _Hash, _Pred, _Alloc> _Hashtable; ^~~~~~~~~~ /usr/include/c++/6/bits/unordered_set.h:102:45: error: 'value' is not a member of 'std::__not_<std::__and_<std::__is_fast_hash<pair_hash>, std::__detail::__is_noexcept_hash<int, pair_hash> > >' typedef typename _Hashtable::key_type key_type; ^~~~~~~~ /usr/include/c++/6/bits/unordered_set.h:103:47: error: 'value' is not a member of 'std::__not_<std::__and_<std::__is_fast_hash<pair_hash>, std::__detail::__is_noexcept_hash<int, pair_hash> > >' typedef typename _Hashtable::value_type value_type; ^~~~~~~~~~ /usr/include/c++/6/bits/unordered_set.h:104:43: error: 'value' is not a member of 'std::__not_<std::__and_<std::__is_fast_hash<pair_hash>, std::__detail::__is_noexcept_hash<int, pair_hash> > >' typedef typename _Hashtable::hasher hasher; ^~~~~~ /usr/include/c++/6/bits/unordered_set.h:105:46: error: 'value' is not a member of 'std::__not_<std::__and_<std::__is_fast_hash<pair_hash>, std::__detail::__is_noexcept_hash<int, pair_hash> > >' typedef typename _Hashtable::key_equal key_equal; ^~~~~~~~~ /usr/include/c++/6/bits/unordered_set.h:106:51: error: 'value' is not a member of 'std::__not_<std::__and_<std::__is_fast_hash<pair_hash>, std::__detail::__is_noexcept_hash<int, pair_hash> > >' typedef typename _Hashtable::allocator_type allocator_type; ^~~~~~~~~~~~~~ Non zero exit status: 1