* François Dumont: > + // Get hash code for a node that comes from another _Hashtable. > + // Reuse a cached hash code if the hash function is stateless, > + // otherwise recalculate it using our own hash function. > + __hash_code > + _M_hash_code_ext(const __node_value_type& __from) const > + { > + if constexpr (__and_<__hash_cached, is_empty<_Hash>>::value) > + return __from._M_hash_code; > + else > + return this->_M_hash_code(_ExtractKey{}(__from._M_v())); > + }
Does C++ support stateful hash functions? I don't think so, and I don't see it documented as a GNU extension, either. Thanks, Florian