variant_alternative_selector.hpp

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// SPDX-License-Identifier: BSL-1.0
// SPDX-FileCopyrightText: Copyright (C) 2024 Tobias Hienzsch
 
#ifndef TETL_VARIANT_VARIANT_ALTERNATIVE_SELECTOR_HPP
#define TETL_VARIANT_VARIANT_ALTERNATIVE_SELECTOR_HPP
 
#include <etl/_type_traits/declval.hpp>
#include <etl/_variant/overload.hpp>
 
namespace etl::detail {
 
template <typename T>
struct variant_alternative_selector_single {
    auto operator()(T /*t*/) const -> T;
};
 
template <typename... Ts>
inline constexpr auto variant_alternative_selector = etl::overload{variant_alternative_selector_single<Ts>{}...};
 
template <typename T, typename... Ts>
using variant_alternative_selector_t = decltype(variant_alternative_selector<Ts...>(etl::declval<T>()));
 
} // namespace etl::detail
 
#endif // TETL_VARIANT_VARIANT_ALTERNATIVE_SELECTOR_HPP