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Sprout/sprout/compost/effects/changed_volume.hpp
2016-02-25 18:48:28 +09:00

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2.5 KiB
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/*=============================================================================
Copyright (c) 2011-2016 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_CHANGED_VOLUME_HPP
#define SPROUT_COMPOST_EFFECTS_CHANGED_VOLUME_HPP
#include <sprout/config.hpp>
#include <sprout/functional/multiplies.hpp>
#include <sprout/functional/bind2nd.hpp>
#include <sprout/utility/forward.hpp>
#include <sprout/range/adaptor/transformed.hpp>
namespace sprout {
namespace compost {
namespace effects {
//
// change_volume_holder
//
template<typename T>
class change_volume_holder {
public:
typedef T value_type;
private:
value_type value_;
public:
SPROUT_CONSTEXPR change_volume_holder() SPROUT_DEFAULTED_DEFAULT_CONSTRUCTOR_DECL
change_volume_holder(change_volume_holder const&) = default;
explicit SPROUT_CONSTEXPR change_volume_holder(value_type const& value)
: value_(value)
{}
SPROUT_CONSTEXPR value_type const& value() const {
return value_;
}
};
//
// changed_volume_forwarder
//
class changed_volume_forwarder {
public:
template<typename T>
SPROUT_CONSTEXPR sprout::compost::effects::change_volume_holder<T>
operator()(T const& value) const {
return sprout::compost::effects::change_volume_holder<T>(value);
}
};
//
// changed_volume
//
namespace {
SPROUT_STATIC_CONSTEXPR sprout::compost::effects::changed_volume_forwarder changed_volume = {};
} // anonymous-namespace
//
// operator|
//
template<typename Range, typename T>
inline SPROUT_CONSTEXPR auto
operator|(Range&& lhs, sprout::compost::effects::change_volume_holder<T> const& rhs)
-> decltype(
SPROUT_FORWARD(Range, lhs)
| sprout::adaptors::transformed(sprout::bind2nd(sprout::multiplies<>(), rhs.value()))
)
{
return SPROUT_FORWARD(Range, lhs)
| sprout::adaptors::transformed(sprout::bind2nd(sprout::multiplies<>(), rhs.value()))
;
}
} // namespace effects
using sprout::compost::effects::changed_volume;
} // namespace compost
} // namespace sprout
#endif // #ifndef SPROUT_COMPOST_EFFECTS_CHANGED_VOLUME_HPP