In file included from /usr/include/c++/11/bits/hashtable.h:35,
from /usr/include/c++/11/unordered_map:46,
from /usr/include/c++/11/functional:61,
from /usr/include/c++/11/pstl/glue_algorithm_defs.h:13,
from /usr/include/c++/11/algorithm:74,
from /usr/include/x86_64-linux-gnu/c++/11/bits/stdc++.h:65,
from seats.cpp:1:
/usr/include/c++/11/bits/hashtable_policy.h: In instantiation of 'std::__detail::_Hash_code_base<_Key, _Value, _ExtractKey, _Hash, _RangeHash, _Unused, __cache_hash_code>::__hash_code std::__detail::_Hash_code_base<_Key, _Value, _ExtractKey, _Hash, _RangeHash, _Unused, __cache_hash_code>::_M_hash_code(const _Key&) const [with _Key = std::pair<int, int>; _Value = std::pair<const std::pair<int, int>, int>; _ExtractKey = std::__detail::_Select1st; _Hash = custom_hash; _RangeHash = std::__detail::_Mod_range_hashing; _Unused = std::__detail::_Default_ranged_hash; bool __cache_hash_code = true; std::__detail::_Hash_code_base<_Key, _Value, _ExtractKey, _Hash, _RangeHash, _Unused, __cache_hash_code>::__hash_code = long unsigned int]':
/usr/include/c++/11/bits/hashtable.h:1593:46: required from 'std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::iterator std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::find(const key_type&) [with _Key = std::pair<int, int>; _Value = std::pair<const std::pair<int, int>, int>; _Alloc = std::allocator<std::pair<const std::pair<int, int>, int> >; _ExtractKey = std::__detail::_Select1st; _Equal = std::equal_to<std::pair<int, int> >; _Hash = custom_hash; _RangeHash = std::__detail::_Mod_range_hashing; _Unused = std::__detail::_Default_ranged_hash; _RehashPolicy = std::__detail::_Prime_rehash_policy; _Traits = std::__detail::_Hashtable_traits<true, false, true>; std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::iterator = std::__detail::_Insert_base<std::pair<int, int>, std::pair<const std::pair<int, int>, int>, std::allocator<std::pair<const std::pair<int, int>, int> >, std::__detail::_Select1st, std::equal_to<std::pair<int, int> >, custom_hash, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<true, false, true> >::iterator; std::_Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits>::key_type = std::pair<int, int>]'
/usr/include/c++/11/bits/unordered_map.h:869:25: required from 'std::unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::iterator std::unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::find(const key_type&) [with _Key = std::pair<int, int>; _Tp = int; _Hash = custom_hash; _Pred = std::equal_to<std::pair<int, int> >; _Alloc = std::allocator<std::pair<const std::pair<int, int>, int> >; std::unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::iterator = std::__detail::_Insert_base<std::pair<int, int>, std::pair<const std::pair<int, int>, int>, std::allocator<std::pair<const std::pair<int, int>, int> >, std::__detail::_Select1st, std::equal_to<std::pair<int, int> >, custom_hash, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<true, false, true> >::iterator; std::unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::key_type = std::pair<int, int>]'
seats.cpp:81:20: required from here
/usr/include/c++/11/bits/hashtable_policy.h:1217:23: error: static assertion failed: hash function must be invocable with an argument of key type
1217 | static_assert(__is_invocable<const _Hash&, const _Key&>{},
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/11/bits/hashtable_policy.h:1217:23: note: 'std::__is_invocable<const custom_hash&, const std::pair<int, int>&>{}' evaluates to false
/usr/include/c++/11/bits/hashtable_policy.h:1219:25: error: no match for call to '(const custom_hash) (const std::pair<int, int>&)'
1219 | return _M_hash()(__k);
| ~~~~~~~~~^~~~~
seats.cpp:37:12: note: candidate: 'size_t custom_hash::operator()(uint64_t) const'
37 | size_t operator()(uint64_t x) const {
| ^~~~~~~~
seats.cpp:37:32: note: no known conversion for argument 1 from 'const std::pair<int, int>' to 'uint64_t' {aka 'long unsigned int'}
37 | size_t operator()(uint64_t x) const {
| ~~~~~~~~~^