55 lines
1.8 KiB
C++
55 lines
1.8 KiB
C++
// Copyright (c) OpenMMLab. All rights reserved.
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#ifndef MMDEPLOY_SRC_CORE_CPP_DETECTED_H_
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#define MMDEPLOY_SRC_CORE_CPP_DETECTED_H_
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#include <type_traits>
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namespace mmdeploy::detail {
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struct nonesuch {
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nonesuch() = delete;
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~nonesuch() = delete;
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nonesuch(nonesuch const&) = delete;
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nonesuch(nonesuch const&&) = delete;
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void operator=(nonesuch const&) = delete;
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void operator=(nonesuch&&) = delete;
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};
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template <class Default, class AlwaysVoid, template <class...> class Op, class... Args>
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struct detector {
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using value_t = std::false_type;
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using type = Default;
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};
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template <class Default, template <class...> class Op, class... Args>
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struct detector<Default, std::void_t<Op<Args...>>, Op, Args...> {
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using value_t = std::true_type;
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using type = Op<Args...>;
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};
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template <template <class...> class Op, class... Args>
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using is_detected = typename detector<nonesuch, void, Op, Args...>::value_t;
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template <template <class...> class Op, class... Args>
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using detected_t = typename detector<nonesuch, void, Op, Args...>::type;
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template <template <class...> class Op, class... Args>
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constexpr inline bool is_detected_v = is_detected<Op, Args...>::value;
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template <class Default, template <class...> class Op, class... Args>
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using detected_or = detector<Default, void, Op, Args...>;
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template <class Default, template <class...> class Op, class... Args>
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using detected_or_t = typename detected_or<Default, Op, Args...>::type;
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template <class Expected, template <class...> class Op, class... Args>
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using is_detected_exact = std::is_same<Expected, detected_t<Op, Args...>>;
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template <class To, template <class...> class Op, class... Args>
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using is_detected_convertible = std::is_convertible<detected_t<Op, Args...>, To>;
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} // namespace mmdeploy::detail
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#endif // MMDEPLOY_SRC_CORE_CPP_DETECTED_H_
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