//  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