Sprout/sprout/compost/effects/superposed.hpp
2019-01-07 17:47:17 +09:00

88 lines
2.7 KiB
C++

/*=============================================================================
Copyright (c) 2011-2019 Bolero MURAKAMI
https://github.com/bolero-MURAKAMI/Sprout
Distributed under 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)
=============================================================================*/
#ifndef SPROUT_COMPOST_EFFECTS_SUPERPOSED_HPP
#define SPROUT_COMPOST_EFFECTS_SUPERPOSED_HPP
#include <sprout/config.hpp>
#include <sprout/functional/plus.hpp>
#include <sprout/utility/forward.hpp>
#include <sprout/utility/value_holder/value_holder.hpp>
#include <sprout/utility/lvalue_forward.hpp>
#include <sprout/type_traits/lvalue_reference.hpp>
#include <sprout/range/adaptor/transformed.hpp>
namespace sprout {
namespace compost {
namespace effects {
//
// superpose_holder
//
template<typename RRange>
class superpose_holder {
public:
typedef RRange range2_type;
private:
sprout::value_holder<range2_type&> range_;
public:
SPROUT_CONSTEXPR superpose_holder() SPROUT_DEFAULTED_DEFAULT_CONSTRUCTOR_DECL
superpose_holder(superpose_holder const&) = default;
explicit SPROUT_CONSTEXPR superpose_holder(range2_type& range)
: range_(range)
{}
SPROUT_CONSTEXPR range2_type& range() const {
return range_;
}
};
//
// superposed_forwarder
//
class superposed_forwarder {
public:
template<typename RRange>
SPROUT_CONSTEXPR sprout::compost::effects::superpose_holder<
typename std::remove_reference<typename sprout::lvalue_reference<RRange>::type>::type
>
operator()(RRange&& range) const {
return sprout::compost::effects::superpose_holder<
typename std::remove_reference<typename sprout::lvalue_reference<RRange>::type>::type
>(
sprout::lvalue_forward<RRange>(range)
);
}
};
//
// superposed
//
namespace {
SPROUT_STATIC_CONSTEXPR sprout::compost::effects::superposed_forwarder superposed = {};
} // anonymous-namespace
//
// operator|
//
template<typename Range, typename T>
inline SPROUT_CONSTEXPR auto
operator|(Range&& lhs, sprout::compost::effects::superpose_holder<T> const& rhs)
-> decltype(
SPROUT_FORWARD(Range, lhs)
| sprout::adaptors::transformed(rhs.range(), sprout::plus<>())
)
{
return SPROUT_FORWARD(Range, lhs)
| sprout::adaptors::transformed(rhs.range(), sprout::plus<>())
;
}
} // namespace effects
using sprout::compost::effects::superposed;
} // namespace compost
} // namespace sprout
#endif // #ifndef SPROUT_COMPOST_EFFECTS_SUPERPOSED_HPP