std::hash<void>
#include <x/hash.H> std::unordered_map<std::string, int, std::hash<void>, std::equal_to<void>> table; bool answer(const std::string_view &question) { auto iter=table.find(question); return iter != table.end() && iter->second == 42; }
Including <x/hash.H>
defines a transparent specialization for std::hash
.