// 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 |