value_type.hpp

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//
// Copyright (C) 2014, 2015 Ableton AG, Berlin. All rights reserved.
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#pragma once

#include <atria/meta/detected.hpp>

namespace atria {
namespace meta {

namespace detail {

template <typename T>
using value_type_t = typename T::value_type;

template <typename T>
using iterator_value_t = typename std::iterator_traits<T>::value_type;

template <typename T>
using dereference_t = estd::decay_t<decltype(*std::declval<T>())>;

template <typename T>
using getter_t = estd::decay_t<decltype(std::declval<T>().get())>;

} // namespace detail

template <typename T>
struct get_value_type
  : detected_any<T,
                 detail::value_type_t,
                 detail::iterator_value_t,
                 detail::dereference_t,
                 detail::getter_t>
{};

template <typename T>
using value_t = eval_t<get_value_type<estd::decay_t<T> > >;

} // namespace meta
} // namespace atria