#include<compare>// see [compare.syn]#include<initializer_list>// see [initializer.list.syn]namespace std {// [unord.map], class template unordered_maptemplate<class Key,
class T,
class Hash = hash<Key>,
class Pred = equal_to<Key>,
class Alloc = allocator<pair<const Key, T>>>class unordered_map;
// [unord.multimap], class template unordered_multimaptemplate<class Key,
class T,
class Hash = hash<Key>,
class Pred = equal_to<Key>,
class Alloc = allocator<pair<const Key, T>>>class unordered_multimap;
template<class Key, class T, class Hash, class Pred, class Alloc>booloperator==(const unordered_map<Key, T, Hash, Pred, Alloc>& a,
const unordered_map<Key, T, Hash, Pred, Alloc>& b);
template<class Key, class T, class Hash, class Pred, class Alloc>booloperator==(const unordered_multimap<Key, T, Hash, Pred, Alloc>& a,
const unordered_multimap<Key, T, Hash, Pred, Alloc>& b);
template<class Key, class T, class Hash, class Pred, class Alloc>void swap(unordered_map<Key, T, Hash, Pred, Alloc>& x,
unordered_map<Key, T, Hash, Pred, Alloc>& y)noexcept(noexcept(x.swap(y)));
template<class Key, class T, class Hash, class Pred, class Alloc>void swap(unordered_multimap<Key, T, Hash, Pred, Alloc>& x,
unordered_multimap<Key, T, Hash, Pred, Alloc>& y)noexcept(noexcept(x.swap(y)));
// [unord.map.erasure], erasure for unordered_maptemplate<class K, class T, class H, class P, class A, class Predicate>typename unordered_map<K, T, H, P, A>::size_type
erase_if(unordered_map<K, T, H, P, A>& c, Predicate pred);
// [unord.multimap.erasure], erasure for unordered_multimaptemplate<class K, class T, class H, class P, class A, class Predicate>typename unordered_multimap<K, T, H, P, A>::size_type
erase_if(unordered_multimap<K, T, H, P, A>& c, Predicate pred);
namespace pmr {template<class Key,
class T,
class Hash = hash<Key>,
class Pred = equal_to<Key>>using unordered_map =
std::unordered_map<Key, T, Hash, Pred,
polymorphic_allocator<pair<const Key, T>>>;
template<class Key,
class T,
class Hash = hash<Key>,
class Pred = equal_to<Key>>using unordered_multimap =
std::unordered_multimap<Key, T, Hash, Pred,
polymorphic_allocator<pair<const Key, T>>>;
}}