/*=============================================================================
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Copyright (c) 2001-2014 Joel de Guzman
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Copyright (c) 2001-2011 Hartmut Kaiser
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Distributed under the Boost Software License, Version 1.0. (See accompanying
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file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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==============================================================================*/
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#if !defined(BOOST_SPIRIT_X3_UNUSED_APRIL_16_2006_0616PM)
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#define BOOST_SPIRIT_X3_UNUSED_APRIL_16_2006_0616PM
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#include <iosfwd>
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///////////////////////////////////////////////////////////////////////////////
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namespace boost { namespace spirit { namespace x3
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{
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struct unused_type
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{
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unused_type() = default;
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template <typename T>
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unused_type(T const&)
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{
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}
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template <typename T>
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unused_type const&
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operator=(T const&) const
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{
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return *this;
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}
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template <typename T>
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unused_type&
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operator=(T const&)
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{
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return *this;
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}
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// unused_type can also masquerade as an empty context (see context.hpp)
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template <typename ID>
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unused_type get(ID) const
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{
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return {};
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}
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friend std::ostream& operator<<(std::ostream& out, unused_type const&)
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{
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return out;
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}
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friend std::istream& operator>>(std::istream& in, unused_type&)
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{
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return in;
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}
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};
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constexpr auto unused = unused_type{};
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}}}
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#endif
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