mirror of
https://github.com/bolero-MURAKAMI/Sprout.git
synced 2024-11-14 10:39:05 +00:00
56 lines
1.9 KiB
C++
56 lines
1.9 KiB
C++
/*=============================================================================
|
|
Copyright (c) 2011-2013 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_VARIANT_AS_VARIANT_VISITOR_HPP
|
|
#define SPROUT_VARIANT_AS_VARIANT_VISITOR_HPP
|
|
|
|
#include <utility>
|
|
#include <type_traits>
|
|
#include <sprout/config.hpp>
|
|
#include <sprout/utility/forward.hpp>
|
|
#include <sprout/utility/lvalue_forward.hpp>
|
|
#include <sprout/utility/value_holder/value_holder.hpp>
|
|
#include <sprout/type_traits/lvalue_reference.hpp>
|
|
#include <sprout/variant/static_variant_visitor.hpp>
|
|
|
|
namespace sprout {
|
|
//
|
|
// variant_visitor_wrapper
|
|
//
|
|
template<typename Visitor>
|
|
class variant_visitor_wrapper
|
|
: public sprout::static_variant_visitor
|
|
{
|
|
public:
|
|
typedef Visitor visitor_type;
|
|
typedef sprout::value_holder<visitor_type&> holder_type;
|
|
private:
|
|
holder_type v_;
|
|
public:
|
|
SPROUT_CONSTEXPR explicit variant_visitor_wrapper(typename holder_type::param_type v)
|
|
: v_(v)
|
|
{}
|
|
template<typename T>
|
|
SPROUT_CONSTEXPR auto operator()(T&& t) const
|
|
-> decltype(std::declval<holder_type const>().get()(sprout::forward<T>(t)))
|
|
{
|
|
return v_.get()(sprout::forward<T>(t));
|
|
}
|
|
};
|
|
|
|
//
|
|
// as_variant_visitor
|
|
//
|
|
template<typename Visitor>
|
|
inline SPROUT_CONSTEXPR sprout::variant_visitor_wrapper<typename std::remove_reference<typename sprout::lvalue_reference<Visitor>::type>::type>
|
|
as_variant_visitor(Visitor&& visitor) {
|
|
typedef sprout::variant_visitor_wrapper<typename std::remove_reference<typename sprout::lvalue_reference<Visitor>::type>::type> type;
|
|
return type(sprout::lvalue_forward<Visitor>(visitor));
|
|
}
|
|
} // namespace sprout
|
|
|
|
#endif // #ifndef SPROUT_VARIANT_AS_VARIANT_VISITOR_HPP
|