// boost utility/base_from_member.hpp header file --------------------------// // Copyright 2001, 2003, 2004 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/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> // 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) > \ explicit base_from_member( BOOST_PP_ENUM_BINARY_PARAMS(n, T, x) ) \ : member( BOOST_PP_ENUM_PARAMS(n, x) ) \ {} \ /**/ namespace boost { // 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; base_from_member() : member() {} BOOST_PP_REPEAT_FROM_TO( 1, BOOST_PP_INC(BOOST_BASE_FROM_MEMBER_MAX_ARITY), BOOST_PRIVATE_CTR_DEF, _ ) }; // boost::base_from_member } // namespace boost // Undo any private macros #undef BOOST_PRIVATE_CTR_DEF #endif // BOOST_UTILITY_BASE_FROM_MEMBER_HPP