152 lines
4.6 KiB
Plaintext
152 lines
4.6 KiB
Plaintext
//-----------------------------------------------------------------------------
|
|
// boost variant/detail/apply_visitor_delayed.hpp header file
|
|
// See http://www.boost.org for updates, documentation, and revision history.
|
|
//-----------------------------------------------------------------------------
|
|
//
|
|
// Copyright (c) 2002-2003
|
|
// Eric Friedman
|
|
//
|
|
// 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 BOOST_VARIANT_DETAIL_APPLY_VISITOR_DELAYED_HPP
|
|
#define BOOST_VARIANT_DETAIL_APPLY_VISITOR_DELAYED_HPP
|
|
|
|
#include <boost/variant/detail/generic_result_type.hpp>
|
|
|
|
#include <boost/variant/detail/apply_visitor_unary.hpp>
|
|
#include <boost/variant/detail/apply_visitor_binary.hpp>
|
|
#include <boost/variant/variant_fwd.hpp> // for BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES
|
|
|
|
|
|
#include <boost/variant/detail/has_result_type.hpp>
|
|
#include <boost/core/enable_if.hpp>
|
|
|
|
namespace boost {
|
|
|
|
//////////////////////////////////////////////////////////////////////////
|
|
// function template apply_visitor(visitor)
|
|
//
|
|
// Returns a function object, overloaded for unary and binary usage, that
|
|
// visits its arguments using visitor (or a copy of visitor) via
|
|
// * apply_visitor( visitor, [argument] )
|
|
// under unary invocation, or
|
|
// * apply_visitor( visitor, [argument1], [argument2] )
|
|
// under binary invocation.
|
|
//
|
|
// NOTE: Unlike other apply_visitor forms, the visitor object must be
|
|
// non-const; this prevents user from giving temporary, to disastrous
|
|
// effect (i.e., returned function object would have dead reference).
|
|
//
|
|
|
|
template <typename Visitor>
|
|
class apply_visitor_delayed_t
|
|
{
|
|
public: // visitor typedefs
|
|
|
|
typedef typename Visitor::result_type
|
|
result_type;
|
|
|
|
private: // representation
|
|
|
|
Visitor& visitor_;
|
|
|
|
public: // structors
|
|
|
|
explicit apply_visitor_delayed_t(Visitor& visitor) BOOST_NOEXCEPT
|
|
: visitor_(visitor)
|
|
{
|
|
}
|
|
|
|
#if !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES)
|
|
|
|
public: // N-ary visitor interface
|
|
template <typename... Visitables>
|
|
BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(result_type)
|
|
operator()(Visitables&... visitables) const
|
|
{
|
|
return apply_visitor(visitor_, visitables...);
|
|
}
|
|
|
|
#else // !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES)
|
|
|
|
public: // unary visitor interface
|
|
|
|
template <typename Visitable>
|
|
BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(result_type)
|
|
operator()(Visitable& visitable) const
|
|
{
|
|
return apply_visitor(visitor_, visitable);
|
|
}
|
|
|
|
public: // binary visitor interface
|
|
|
|
template <typename Visitable1, typename Visitable2>
|
|
BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(result_type)
|
|
operator()(Visitable1& visitable1, Visitable2& visitable2) const
|
|
{
|
|
return apply_visitor(visitor_, visitable1, visitable2);
|
|
}
|
|
|
|
#endif // !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES)
|
|
|
|
private:
|
|
apply_visitor_delayed_t& operator=(const apply_visitor_delayed_t&);
|
|
|
|
};
|
|
|
|
template <typename Visitor>
|
|
inline typename boost::enable_if<
|
|
boost::detail::variant::has_result_type<Visitor>,
|
|
apply_visitor_delayed_t<Visitor>
|
|
>::type apply_visitor(Visitor& visitor)
|
|
{
|
|
return apply_visitor_delayed_t<Visitor>(visitor);
|
|
}
|
|
|
|
#if !defined(BOOST_NO_CXX14_DECLTYPE_AUTO) && !defined(BOOST_NO_CXX11_DECLTYPE_N3276) \
|
|
&& !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES)
|
|
|
|
template <typename Visitor>
|
|
class apply_visitor_delayed_cpp14_t
|
|
{
|
|
private: // representation
|
|
Visitor& visitor_;
|
|
|
|
public: // structors
|
|
|
|
explicit apply_visitor_delayed_cpp14_t(Visitor& visitor) BOOST_NOEXCEPT
|
|
: visitor_(visitor)
|
|
{
|
|
}
|
|
|
|
public: // N-ary visitor interface
|
|
template <typename... Visitables>
|
|
decltype(auto) operator()(Visitables&... visitables) const
|
|
{
|
|
return apply_visitor(visitor_, visitables...);
|
|
}
|
|
|
|
private:
|
|
apply_visitor_delayed_cpp14_t& operator=(const apply_visitor_delayed_cpp14_t&);
|
|
|
|
};
|
|
|
|
template <typename Visitor>
|
|
inline typename boost::disable_if<
|
|
boost::detail::variant::has_result_type<Visitor>,
|
|
apply_visitor_delayed_cpp14_t<Visitor>
|
|
>::type apply_visitor(Visitor& visitor)
|
|
{
|
|
return apply_visitor_delayed_cpp14_t<Visitor>(visitor);
|
|
}
|
|
|
|
#endif // !defined(BOOST_NO_CXX14_DECLTYPE_AUTO) && !defined(BOOST_NO_CXX11_DECLTYPE_N3276)
|
|
// && !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES)
|
|
|
|
|
|
} // namespace boost
|
|
|
|
#endif // BOOST_VARIANT_DETAIL_APPLY_VISITOR_DELAYED_HPP
|