173 lines
		
	
	
		
			5.7 KiB
		
	
	
	
		
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			173 lines
		
	
	
		
			5.7 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
| //  boost utility/base_from_member.hpp header file  --------------------------//
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| 
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| //  Copyright 2001, 2003, 2004, 2012 Daryle Walker.  Use, modification, and
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| //  distribution are subject to the Boost Software License, Version 1.0.  (See
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| //  accompanying file LICENSE_1_0.txt or a copy at
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| //  <http://www.boost.org/LICENSE_1_0.txt>.)
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| 
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| //  See <http://www.boost.org/libs/utility/> for the library's home page.
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| 
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| #ifndef BOOST_UTILITY_BASE_FROM_MEMBER_HPP
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| #define BOOST_UTILITY_BASE_FROM_MEMBER_HPP
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| 
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| #include <boost/config.hpp>
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| #include <boost/preprocessor/arithmetic/inc.hpp>
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| #include <boost/preprocessor/repetition/enum_binary_params.hpp>
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| #include <boost/preprocessor/repetition/enum_params.hpp>
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| #include <boost/preprocessor/repetition/repeat_from_to.hpp>
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| #include <boost/type_traits/is_same.hpp>
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| #include <boost/type_traits/remove_cv.hpp>
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| #include <boost/type_traits/remove_reference.hpp>
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| #include <boost/utility/enable_if.hpp>
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| 
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| 
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| //  Base-from-member arity configuration macro  ------------------------------//
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| 
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| // The following macro determines how many arguments will be in the largest
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| // constructor template of base_from_member.  Constructor templates will be
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| // generated from one argument to this maximum.  Code from other files can read
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| // this number if they need to always match the exact maximum base_from_member
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| // uses.  The maximum constructor length can be changed by overriding the
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| // #defined constant.  Make sure to apply the override, if any, for all source
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| // files during project compiling for consistency.
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| 
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| // Contributed by Jonathan Turkanis
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| 
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| #ifndef BOOST_BASE_FROM_MEMBER_MAX_ARITY
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| #define BOOST_BASE_FROM_MEMBER_MAX_ARITY  10
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| #endif
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| 
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| 
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| //  An iteration of a constructor template for base_from_member  -------------//
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| 
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| // A macro that should expand to:
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| //     template < typename T1, ..., typename Tn >
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| //     base_from_member( T1 x1, ..., Tn xn )
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| //         : member( x1, ..., xn )
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| //         {}
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| // This macro should only persist within this file.
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| 
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| #define BOOST_PRIVATE_CTR_DEF( z, n, data )                   \
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|     template < BOOST_PP_ENUM_PARAMS(n, typename T) >          \
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|     base_from_member( BOOST_PP_ENUM_BINARY_PARAMS(n, T, x) )  \
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|         : member( BOOST_PP_ENUM_PARAMS(n, x) )                \
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|         {}                                                    \
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|     /**/
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| 
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| 
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| namespace boost
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| {
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| 
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| namespace detail
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| {
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| 
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| //  Type-unmarking class template  -------------------------------------------//
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| 
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| // Type-trait to get the raw type, i.e. the type without top-level reference nor
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| // cv-qualification, from a type expression.  Mainly for function arguments, any
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| // reference part is stripped first.
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| 
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| // Contributed by Daryle Walker
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| 
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| template < typename T >
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| struct remove_cv_ref
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| {
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|     typedef typename ::boost::remove_cv<typename
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|      ::boost::remove_reference<T>::type>::type  type;
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| 
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| };  // boost::detail::remove_cv_ref
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| 
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| //  Unmarked-type comparison class template  ---------------------------------//
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| 
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| // Type-trait to check if two type expressions have the same raw type.
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| 
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| // Contributed by Daryle Walker, based on a work-around by Luc Danton
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| 
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| template < typename T, typename U >
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| struct is_related
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|     : public ::boost::is_same<
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|      typename ::boost::detail::remove_cv_ref<T>::type,
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|      typename ::boost::detail::remove_cv_ref<U>::type >
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| {};
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| 
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| //  Enable-if-on-unidentical-unmarked-type class template  -------------------//
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| 
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| // Enable-if on the first two type expressions NOT having the same raw type.
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| 
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| // Contributed by Daryle Walker, based on a work-around by Luc Danton
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| 
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| #ifndef BOOST_NO_CXX11_VARIADIC_TEMPLATES
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| template<typename ...T>
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| struct enable_if_unrelated
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|     : public ::boost::enable_if_c<true>
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| {};
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| 
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| template<typename T, typename U, typename ...U2>
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| struct enable_if_unrelated<T, U, U2...>
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|     : public ::boost::disable_if< ::boost::detail::is_related<T, U> >
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| {};
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| #endif
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| 
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| }  // namespace boost::detail
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| 
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| 
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| //  Base-from-member class template  -----------------------------------------//
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| 
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| // Helper to initialize a base object so a derived class can use this
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| // object in the initialization of another base class.  Used by
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| // Dietmar Kuehl from ideas by Ron Klatcho to solve the problem of a
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| // base class needing to be initialized by a member.
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| 
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| // Contributed by Daryle Walker
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| 
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| template < typename MemberType, int UniqueID = 0 >
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| class base_from_member
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| {
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| protected:
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|     MemberType  member;
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| 
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| #if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES) && \
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|     !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES) && \
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|     !defined(BOOST_NO_CXX11_FUNCTION_TEMPLATE_DEFAULT_ARGS) && \
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|     !(defined(__GNUC__) && (__GNUC__ == 4) && (__GNUC_MINOR__ < 4))
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|     template <typename ...T, typename EnableIf = typename
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|      ::boost::detail::enable_if_unrelated<base_from_member, T...>::type>
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|     explicit BOOST_CONSTEXPR base_from_member( T&& ...x )
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|         BOOST_NOEXCEPT_IF( BOOST_NOEXCEPT_EXPR(::new ((void*) 0) MemberType(
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|          static_cast<T&&>(x)... )) )  // no std::is_nothrow_constructible...
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|         : member( static_cast<T&&>(x)... )     // ...nor std::forward needed
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|         {}
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| #else
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|     base_from_member()
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|         : member()
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|         {}
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| 
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|     template < typename T0 > explicit base_from_member( T0 x0 ) : member( x0 ) {}
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|     BOOST_PP_REPEAT_FROM_TO( 2, BOOST_PP_INC(BOOST_BASE_FROM_MEMBER_MAX_ARITY),
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|      BOOST_PRIVATE_CTR_DEF, _ )
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| #endif
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| 
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| };  // boost::base_from_member
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| 
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| template < typename MemberType, int UniqueID >
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| class base_from_member<MemberType&, UniqueID>
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| {
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| protected:
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|     MemberType& member;
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| 
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|     explicit BOOST_CONSTEXPR base_from_member( MemberType& x )
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|         BOOST_NOEXCEPT
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|         : member( x )
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|         {}
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| 
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| };  // boost::base_from_member
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| 
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| }  // namespace boost
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| 
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| 
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| // Undo any private macros
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| #undef BOOST_PRIVATE_CTR_DEF
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| 
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| 
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| #endif  // BOOST_UTILITY_BASE_FROM_MEMBER_HPP
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