This is quite unfortunate. The way to get a really good hash table is by enforcing a bunch of simplifying assumptions (power of 2 sizes, sentinel values, etc).

This is quite unfortunate. The way to get a really good hash table is by enforcing a bunch of simplifying assumptions (power of 2 sizes, sentinel values, etc). But the C++ committee has to make the "one true table" for everyone. std::map actually seems to fit this role better. It works reasonable well for many workloads and types without tuning a bunch of parameters.