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#ifndef RFL_PARSING_SCHEMAFUL_VARIANTREADER_HPP_
#define RFL_PARSING_SCHEMAFUL_VARIANTREADER_HPP_
#include <type_traits>
#include <utility>
#include "../../Result.hpp"
#include "../../internal/nth_element_t.hpp"
namespace rfl::parsing::schemaful {
template <class R, class W, class VariantType, class ProcessorsType,
class... AlternativeTypes>
class VariantReader {
public:
static Result<VariantType> read(
const R& _r, const size_t _index,
const typename R::InputVarType& _var) noexcept {
return [&]<size_t... _is>(std::integer_sequence<size_t, _is...>) {
Result<VariantType> result =
error("Could not parse union: Index out of bounds.");
(try_one_type<_is>(_r, _index, _var, &result), ...);
return result;
}(std::make_integer_sequence<size_t, sizeof...(AlternativeTypes)>());
}
private:
template <size_t _i>
static void try_one_type(const R& _r, const size_t _index,
const typename R::InputVarType& _var,
Result<VariantType>* _result) noexcept {
if (_index == _i) {
using T = internal::nth_element_t<_i, AlternativeTypes...>;
*_result =
Parser<R, W, std::remove_cvref_t<T>, ProcessorsType>::read(_r, _var)
.transform(
[](auto&& _val) -> VariantType { return std::move(_val); });
}
}
};
} // namespace rfl::parsing::schemaful
#endif
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