In file included from /in/driver/main.cpp:5:0:
/in/hashtable.hpp: In instantiation of 'Value& HashTable<Key, Value, Hash, KeyEqual>::operator[](const Key&) [with Key = int; Value = int; Hash = std::hash<int>; KeyEqual = std::equal_to<int>]':
/in/driver/main.cpp:129:94:   required from here
/in/hashtable.hpp:388:57: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
             if (firstBucketIt == buckets.end() || index < std::distance(buckets.begin(), firstBucketIt)) {
                                                   ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/in/hashtable.hpp: In instantiation of '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:323:22:   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:302:53: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
         if (firstBucketIt == buckets.end() || index < std::distance(buckets.begin(), firstBucketIt)) {
                                               ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cc1plus: all warnings being treated as errors