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