// Copyright David Abrahams, Daniel Wallin 2003.
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// Distributed under the Boost Software License, Version 1.0.
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// (See accompanying file LICENSE_1_0.txt or copy at
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// http://www.boost.org/LICENSE_1_0.txt)
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#ifndef BOOST_PARAMETER_AUX_PACK_DEDUCE_TAG_HPP
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#define BOOST_PARAMETER_AUX_PACK_DEDUCE_TAG_HPP
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namespace boost { namespace parameter { namespace aux {
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template <
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typename Argument
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, typename ArgumentPack
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, typename DeducedArgs
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, typename UsedArgs
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, typename TagFn
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, typename EmitsErrors
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>
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struct deduce_tag;
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}}} // namespace boost::parameter::aux
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#include <boost/parameter/aux_/lambda_tag.hpp>
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#include <boost/parameter/config.hpp>
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#include <boost/mpl/apply_wrap.hpp>
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#include <boost/mpl/lambda.hpp>
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#if defined(BOOST_PARAMETER_CAN_USE_MP11)
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namespace boost { namespace parameter { namespace aux {
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template <typename Predicate, typename Argument, typename ArgumentPack>
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struct deduce_tag_condition_mpl
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: ::boost::mpl::apply_wrap2<
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typename ::boost::mpl::lambda<
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Predicate
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, ::boost::parameter::aux::lambda_tag
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>::type
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, Argument
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, ArgumentPack
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>
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{
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};
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}}} // namespace boost::parameter::aux
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#include <boost/parameter/aux_/has_nested_template_fn.hpp>
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#include <boost/mp11/list.hpp>
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#include <boost/mp11/utility.hpp>
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namespace boost { namespace parameter { namespace aux {
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template <typename Predicate, typename Argument, typename ArgumentPack>
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struct deduce_tag_condition_mp11
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{
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using type = ::boost::mp11::mp_apply_q<
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Predicate
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, ::boost::mp11::mp_list<Argument,ArgumentPack>
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>;
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};
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template <typename Predicate, typename Argument, typename ArgumentPack>
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using deduce_tag_condition = ::boost::mp11::mp_if<
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::boost::parameter::aux::has_nested_template_fn<Predicate>
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, ::boost::parameter::aux
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::deduce_tag_condition_mp11<Predicate,Argument,ArgumentPack>
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, ::boost::parameter::aux
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::deduce_tag_condition_mpl<Predicate,Argument,ArgumentPack>
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>;
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}}} // namespace boost::parameter::aux
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#else
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#include <boost/mpl/bool.hpp>
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#include <boost/mpl/if.hpp>
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#include <boost/mpl/eval_if.hpp>
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#include <boost/mpl/assert.hpp>
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#endif // BOOST_PARAMETER_CAN_USE_MP11
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#include <boost/parameter/aux_/set.hpp>
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#include <boost/parameter/aux_/pack/tag_type.hpp>
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#include <boost/parameter/aux_/pack/tag_deduced.hpp>
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namespace boost { namespace parameter { namespace aux {
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// Helper for deduce_tag<...>, below.
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template <
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typename Argument
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, typename ArgumentPack
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, typename DeducedArgs
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, typename UsedArgs
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, typename TagFn
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, typename EmitsErrors
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>
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class deduce_tag0
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{
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typedef typename DeducedArgs::spec _spec;
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#if defined(BOOST_PARAMETER_CAN_USE_MP11)
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typedef typename ::boost::parameter::aux::deduce_tag_condition<
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typename _spec::predicate
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#else
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typedef typename ::boost::mpl::apply_wrap2<
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typename ::boost::mpl::lambda<
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typename _spec::predicate
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, ::boost::parameter::aux::lambda_tag
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>::type
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#endif
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, Argument
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, ArgumentPack
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>::type _condition;
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#if !defined(BOOST_PARAMETER_CAN_USE_MP11)
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// Deduced parameter matches several arguments.
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BOOST_MPL_ASSERT((
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typename ::boost::mpl::eval_if<
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typename ::boost::parameter::aux::has_key_<
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UsedArgs
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, typename ::boost::parameter::aux::tag_type<_spec>::type
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>::type
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, ::boost::mpl::eval_if<
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_condition
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, ::boost::mpl::if_<
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EmitsErrors
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, ::boost::mpl::false_
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, ::boost::mpl::true_
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>
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, ::boost::mpl::true_
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>
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, ::boost::mpl::true_
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>::type
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));
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#endif // BOOST_PARAMETER_CAN_USE_MP11
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public:
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#if defined(BOOST_PARAMETER_CAN_USE_MP11)
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using type = typename ::boost::mp11::mp_if<
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#else
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typedef typename ::boost::mpl::eval_if<
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#endif
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_condition
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, ::boost::parameter::aux
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::tag_deduced<UsedArgs,_spec,Argument,TagFn>
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, ::boost::parameter::aux::deduce_tag<
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Argument
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, ArgumentPack
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, typename DeducedArgs::tail
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, UsedArgs
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, TagFn
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, EmitsErrors
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>
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#if defined(BOOST_PARAMETER_CAN_USE_MP11)
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>::type;
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#else
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>::type type;
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#endif
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};
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}}} // namespace boost::parameter::aux
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#include <boost/parameter/aux_/void.hpp>
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#if defined(BOOST_PARAMETER_CAN_USE_MP11)
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#include <type_traits>
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#else
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#include <boost/mpl/pair.hpp>
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#include <boost/type_traits/is_same.hpp>
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#endif
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namespace boost { namespace parameter { namespace aux {
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// Tries to deduced a keyword tag for a given Argument.
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// Returns an mpl::pair<> consisting of the tagged_argument<>,
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// and an mpl::set<> where the new tag has been inserted.
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//
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// Argument: The argument type to be tagged.
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//
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// ArgumentPack: The ArgumentPack built so far.
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//
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// DeducedArgs: A specialization of deduced_item<> (see below).
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// A list containing only the deduced ParameterSpecs.
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//
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// UsedArgs: An mpl::set<> containing the keyword tags used so far.
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//
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// TagFn: A metafunction class used to tag positional or deduced
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// arguments with a keyword tag.
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template <
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typename Argument
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, typename ArgumentPack
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, typename DeducedArgs
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, typename UsedArgs
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, typename TagFn
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, typename EmitsErrors
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>
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struct deduce_tag
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#if defined(BOOST_PARAMETER_CAN_USE_MP11)
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: ::boost::mp11::mp_if<
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::std::is_same<DeducedArgs,::boost::parameter::void_>
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, ::boost::mp11::mp_identity<
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::boost::mp11::mp_list< ::boost::parameter::void_,UsedArgs>
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>
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#else
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: ::boost::mpl::eval_if<
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::boost::is_same<DeducedArgs,::boost::parameter::void_>
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, ::boost::mpl::pair< ::boost::parameter::void_,UsedArgs>
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#endif
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, ::boost::parameter::aux::deduce_tag0<
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Argument
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, ArgumentPack
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, DeducedArgs
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, UsedArgs
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, TagFn
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, EmitsErrors
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>
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>
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{
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};
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}}} // namespace boost::parameter::aux
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#endif // include guard
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