bool prepare_invoke(message& msg, tuple_type* out) {
// detach msg before invoking m_fun if needed
if (is_manipulator) {
msg.force_detach();
}
intermediate_tuple it;
detail::meta_elements<pattern> ms;
// check if try_match() reports success
if (!detail::try_match(msg, ms.arr.data(), ms.arr.size(), it.data)) {
return false;
}
match_case_zipper zip;
using indices_type = typename detail::il_indices<intermediate_tuple>::type;
//indices_type indices;
typename detail::il_take<indices_type, detail::tl_size<projections>::value - num_fun_args>::type lefts;
typename detail::il_right<indices_type, num_fun_args>::type rights;
has_none hn;
// check if guards of discarded arguments are fulfilled
auto lhs_tup = tuple_zip(zip, lefts, m_ps, it);
if (detail::apply_args(hn, detail::get_indices(lhs_tup), lhs_tup)) {
return false;
}
// zip remaining arguments into output tuple
new (out) tuple_type(tuple_zip(zip, rights, m_ps, it));
//tuple_type rhs_tup = tuple_zip(zip, rights, m_ps, it);
// check if remaining guards are fulfilled
if (detail::apply_args(hn, detail::get_indices(*out), *out)) {
out->~tuple_type();
return false;
}
return true;
}
match_case::result invoke(optional<message>& res, message& msg) override {
intermediate_tuple it;
detail::meta_elements<pattern> ms;
// check if try_match() reports success
if (!detail::try_match(msg, ms.arr.data(), ms.arr.size(), it.data)) {
return match_case::no_match;
}
// detach msg before invoking m_fun if needed
if (is_manipulator) {
msg.force_detach();
// update pointers in our intermediate tuple
for (size_t i = 0; i < msg.size(); ++i) {
// msg is guaranteed to be detached, hence we don't need to
// check this condition over and over again via mutable_at
it[i] = const_cast<void*>(msg.at(i));
}
}
lfinvoker<std::is_same<result_type, void>::value, F> fun{m_fun};
detail::optional_message_visitor omv;
auto funres = apply_args(fun, detail::get_indices(it), it);
res = omv(funres);
return match_case::match;
}