In file included from /in/driver/main.cpp:5:0:
/in/hashtable.hpp: In instantiation of 'HashTable<Key, Value, Hash, KeyEqual>& HashTable<Key, Value, Hash, KeyEqual>::operator=(const HashTable<Key, Value, Hash, KeyEqual>&) [with Key = int; Value = int; Hash = std::hash<int>; KeyEqual = std::equal_to<int>]':
/in/hashtable.hpp:427:15:   required from 'void HashTable<Key, Value, Hash, KeyEqual>::rehash(size_t) [with Key = int; Value = int; Hash = std::hash<int>; KeyEqual = std::equal_to<int>; size_t = long unsigned int]'
/in/hashtable.hpp:304:19:   required from 'bool HashTable<Key, Value, Hash, KeyEqual>::insert(const HashTable<Key, Value, Hash, KeyEqual>::Iterator&, const Key&, const Value&) [with Key = int; Value = int; Hash = std::hash<int>; KeyEqual = std::equal_to<int>]'
/in/hashtable.hpp:322:22:   required from 'bool HashTable<Key, Value, Hash, KeyEqual>::insert(const Key&, const Value&) [with Key = int; Value = int; Hash = std::hash<int>; KeyEqual = std::equal_to<int>]'
/in/driver/main.cpp:111:43:   required from here
/in/hashtable.hpp:225:28: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
         for (auto i = 0; i < that.buckets.size(); ++i) {
cc1plus: all warnings being treated as errors