HasType.h

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// Copyright 2015 Sensics, Inc.
// TypePack is part of OSVR-Core.
//
// Incorporates code from "meta":
// Copyright Eric Niebler 2014-2015
//
// Use, modification and distribution is subject to the
// Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
//
// Project home: https://github.com/ericniebler/meta
//

#ifndef INCLUDED_HasType_h_GUID_C99B75F2_4F44_49BD_6152_3CF9B0B80DAB
#define INCLUDED_HasType_h_GUID_C99B75F2_4F44_49BD_6152_3CF9B0B80DAB

// Internal Includes
#include "Void.h"

// Library/third-party includes
// - none

// Standard includes
#include <type_traits>

namespace osvr {
namespace typepack {
    namespace detail {
        template <typename, typename = void> struct has_type_ {
            using type = std::false_type;
        };

        template <typename T> struct has_type_<T, void_<typename T::type>> {
            using type = std::true_type;
        };

    } // namespace detail

    template <typename T> using has_type = t_<detail::has_type_<T>>;
} // namespace typepack
} // namespace osvr

#endif // INCLUDED_HasType_h_GUID_C99B75F2_4F44_49BD_6152_3CF9B0B80DAB