draconisplusplus/include/rfl/internal/to_ptr_named_tuple.hpp

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2024-05-31 22:59:00 -04:00
#ifndef RFL_INTERNAL_TO_PTR_NAMED_TUPLE_HPP_
#define RFL_INTERNAL_TO_PTR_NAMED_TUPLE_HPP_
#include <iostream>
#include <tuple>
#include "../always_false.hpp"
#include "../field_names_t.hpp"
#include "../make_named_tuple.hpp"
#include "copy_flattened_tuple_to_named_tuple.hpp"
#include "has_fields.hpp"
#include "has_flatten_fields.hpp"
#include "is_empty.hpp"
#include "is_field.hpp"
#include "is_named_tuple.hpp"
#include "to_flattened_ptr_tuple.hpp"
#include "to_ptr_field_tuple.hpp"
namespace rfl {
namespace internal {
template <class PtrFieldTuple, class... Args>
auto flatten_ptr_field_tuple(PtrFieldTuple& _t, Args&&... _args) {
constexpr auto i = sizeof...(Args);
if constexpr (i == std::tuple_size_v<std::remove_cvref_t<PtrFieldTuple>>) {
return std::tuple_cat(std::forward<Args>(_args)...);
} else {
using T = std::tuple_element_t<i, std::remove_cvref_t<PtrFieldTuple>>;
if constexpr (internal::is_flatten_field<T>::value) {
auto subtuple = internal::to_ptr_field_tuple(*std::get<i>(_t).get());
return flatten_ptr_field_tuple(_t, std::forward<Args>(_args)...,
flatten_ptr_field_tuple(subtuple));
} else {
return flatten_ptr_field_tuple(_t, std::forward<Args>(_args)...,
std::make_tuple(std::get<i>(_t)));
}
}
}
template <class PtrFieldTuple>
auto field_tuple_to_named_tuple(PtrFieldTuple& _ptr_field_tuple) {
const auto ft_to_nt = []<class... Fields>(Fields&&... _fields) {
return make_named_tuple(_fields...);
};
if constexpr (!has_flatten_fields<std::remove_cvref_t<PtrFieldTuple>>()) {
return std::apply(ft_to_nt, std::move(_ptr_field_tuple));
} else {
const auto flattened_tuple = flatten_ptr_field_tuple(_ptr_field_tuple);
return std::apply(ft_to_nt, flattened_tuple);
}
}
/// Generates a named tuple that contains pointers to the original values in
/// the struct.
template <class T>
auto to_ptr_named_tuple(T&& _t) {
if constexpr (has_fields<std::remove_cvref_t<T>>()) {
if constexpr (std::is_pointer_v<std::remove_cvref_t<T>>) {
return to_ptr_named_tuple(*_t);
} else if constexpr (is_named_tuple_v<std::remove_cvref_t<T>>) {
return nt_to_ptr_named_tuple(_t);
} else {
auto ptr_field_tuple = to_ptr_field_tuple(_t);
return field_tuple_to_named_tuple(ptr_field_tuple);
}
} else if constexpr (is_empty<T>()) {
return rfl::NamedTuple<>();
} else {
using FieldNames = rfl::field_names_t<T>;
auto flattened_ptr_tuple = to_flattened_ptr_tuple(_t);
return copy_flattened_tuple_to_named_tuple<FieldNames>(flattened_ptr_tuple);
}
}
} // namespace internal
} // namespace rfl
#endif