[Bug libstdc++/106275] unordered_map with std::string key, std::hash<std::string>, and custom equality predicate weirdness

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106275

--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> ---
This "bug" (i.e. doing a linear search for small containers using slow hash
functions) makes the find operation more than twice as fast:

BM_std_hash          4.67 ns         4.66 ns    150610579
BM_custom_hash       12.0 ns         12.0 ns     57529241

See PR 68303 for more details.