147     struct preset_base {  struct
151         preset_base() {}  in preset_base()  argument
152         preset_base(const preset_base&) = delete;
153         preset_base(preset_base&&) = delete;
154         preset_base& operator=(const preset_base&) = delete;  argument
155         preset_base& operator=(preset_base&&) = delete;  argument
161     struct preset_default : preset_base<Key, Value> {
162         using cache_type = typename preset_base<Key, Value>::cache_type;
176     struct preset1 : preset_base<std::string, std::string> {
191     struct preset_call_count : preset_base<int, int> {
205     struct preset_instance_count : preset_base<
224     struct preset_map_instance_count : preset_base<