39   std::optional<Extern> get_export(std::string_view name);
86 template <> struct WasmType<std::optional<ExternRef>> {
90                     std::optional<ExternRef> &&ref) {  in store()
98                     const std::optional<ExternRef> &ref) {  in store()
105   static std::optional<ExternRef> load(Store::Context cx,  in load()
108       return std::nullopt;  in load()
138     return WasmTypeList<std::tuple<T>>::matches(types);  in matches()
150   static std::vector<ValType> types() { return {WasmType<T>::kind}; }  in types()
154 template <> struct WasmTypeList<std::monostate> {
159                     const std::monostate &t) {  in store()
164   static std::monostate load(Store::Context cx, wasmtime_val_raw_t *storage) {  in load()
167     return std::monostate();  in load()
169   static std::vector<ValType> types() { return {}; }  in types()
173 template <typename... T> struct WasmTypeList<std::tuple<T...>> {
184                     std::tuple<T...> &&t) {  in store()
186     std::apply(  in store()
193                     const std::tuple<T...> &t) {  in store()
195     std::apply(  in store()
201   static std::tuple<T...> load(Store::Context cx, wasmtime_val_raw_t *storage) {  in load()
203     return std::tuple<T...>{WasmType<T>::load(cx, storage++)...}; // NOLINT  in load()
205   static std::vector<ValType> types() { return {WasmType<T>::kind...}; }  in types()
215   static std::optional<Trap> invoke(F f, Caller cx, wasmtime_val_raw_t *raw,  in invoke()
219     return std::nullopt;  in invoke()
225   using Results = WasmTypeList<std::tuple<>>;
228   static std::optional<Trap> invoke(F f, Caller cx, wasmtime_val_raw_t *raw,  in invoke()
233     return std::nullopt;  in invoke()
239 template <> struct WasmHostRet<std::monostate> : public WasmHostRet<void> {};
247   static std::optional<Trap> invoke(F f, Caller cx, wasmtime_val_raw_t *raw,  in invoke()
254     return std::nullopt;  in invoke()
263   using Params = WasmTypeList<std::tuple<A...>>;
267   static std::optional<Trap> invoke(F &f, Caller cx, wasmtime_val_raw_t *raw) {  in invoke()
269     return std::apply(  in invoke()
282   static std::optional<Trap> invoke(F &f, Caller cx, wasmtime_val_raw_t *raw) {  in invoke()
283     auto params = WasmTypeList<std::tuple<A...>>::load(cx, raw);  in invoke()
284     return std::apply(  in invoke()
315 struct WasmHostFunc<T, std::void_t<decltype(&T::operator())>>
355     Result<std::monostate, Trap> result =  in raw_callback()
380     std::unique_ptr<F> ptr(reinterpret_cast<F *>(env)); // NOLINT  in raw_finalize()
419             std::enable_if_t<
420                 std::is_invocable_r_v<Result<std::monostate, Trap>, F, Caller,
425                       std::make_unique<F>(f).release(), raw_finalize<F>, &func);
467             std::enable_if_t<WasmHostFunc<F>::Params::valid, bool> = true,
468             std::enable_if_t<WasmHostFunc<F>::Results::valid, bool> = true>
476                                 std::make_unique<F>(f).release(),  in wrap()
502   TrapResult<std::vector<Val>> call(Store::Context cx, const I &begin,  in call()
504     std::vector<wasmtime_val_t> raw_params;  in call()
510     std::vector<wasmtime_val_t> raw_results(nresults);  in call()
523     std::vector<Val> results;  in call()
537   TrapResult<std::vector<Val>> call(Store::Context cx,  in call()
538                                     const std::vector<Val> &params) const {  in call()
548   TrapResult<std::vector<Val>>
549   call(Store::Context cx, const std::initializer_list<Val> &params) const {  in call()
576             std::enable_if_t<WasmTypeList<Params>::valid, bool> = true,
577             std::enable_if_t<WasmTypeList<Results>::valid, bool> = true>
613     std::array<wasmtime_val_raw_t, std::max(WasmTypeList<Params>::size,  in call()
636 inline Val::Val(std::optional<Func> func) : val{} {  in Val()
645 inline Val::Val(Func func) : Val(std::optional(func)) {}  in Val()
646 inline Val::Val(ExternRef ptr) : Val(std::optional(ptr)) {}  in Val()
647 inline Val::Val(AnyRef ptr) : Val(std::optional(ptr)) {}  in Val()
649 inline std::optional<Func> Val::funcref() const {  in funcref()
651     std::abort();  in funcref()
654     return std::nullopt;  in funcref()
660 template <> struct detail::WasmType<std::optional<Func>> {
667                     const std::optional<Func> func) {  in store()
675   static std::optional<Func> load(Store::Context cx, wasmtime_val_raw_t *p) {  in load()
677       return std::nullopt;  in load()