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#ifndef RFL_INTERNAL_DEFINEVARIANT_HPP_
#define RFL_INTERNAL_DEFINEVARIANT_HPP_
#include <variant>
namespace rfl {
namespace internal {
/// Allows you to combine several variants.
template <class... Vars>
struct define_variant;
/// Recursive case - both variants.
template <class... Vars1, class... Vars2, class... Tail>
struct define_variant<std::variant<Vars1...>, std::variant<Vars2...>, Tail...> {
using type = typename define_variant<std::variant<Vars1..., Vars2...>,
Tail...>::type;
};
/// Recursive case - variant plus other type.
template <class... Vars, class Head, class... Tail>
struct define_variant<std::variant<Vars...>, Head, Tail...> {
using type =
typename define_variant<std::variant<Vars..., Head>, Tail...>::type;
};
/// Recursive case - other type.
template <class Head, class... Tail>
struct define_variant<Head, Tail...> {
using type = typename define_variant<std::variant<Head>, Tail...>::type;
};
/// Special case - only a single variant is left.
template <class... Vars>
struct define_variant<std::variant<Vars...>> {
using type = std::variant<Vars...>;
};
} // namespace internal
} // namespace rfl
#endif
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