If you wish to use a different equality function, you will also need to use a matching hash function. For example, to implement a case insensitive dictionary you need to define a case insensitive equality predicate and hash function:
An link:../../../benchmark/string_stats.cpp[example^] is provided that displays container statistics for `boost::hash<std::string>`, an implementation of the https://en.wikipedia.org/wiki/Fowler%E2%80%93Noll%E2%80%93Vo_hash_function#FNV-1a_hash[FNV-1a hash^] and two ill-behaved custom hash functions that have been incorrectly marked as avalanching: