//  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