Correct backslash escaping to only operate on non-'path' and 'tool' types.
#if !defined(BOOST_PP_IS_ITERATING)
///// header body
#ifndef BOOST_MPL_APPLY_FWD_HPP_INCLUDED
#define BOOST_MPL_APPLY_FWD_HPP_INCLUDED
// Copyright Aleksey Gurtovoy 2000-2004
//
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
//
// See http://www.boost.org/libs/mpl for documentation.
// $Id: apply_fwd.hpp 49267 2008-10-11 06:19:02Z agurtovoy $
// $Date: 2008-10-11 02:19:02 -0400 (Sat, 11 Oct 2008) $
// $Revision: 49267 $
#if !defined(BOOST_MPL_PREPROCESSING_MODE)
# include <boost/mpl/aux_/na.hpp>
#endif
#include <boost/mpl/aux_/config/use_preprocessed.hpp>
#if !defined(BOOST_MPL_CFG_NO_PREPROCESSED_HEADERS) \
&& !defined(BOOST_MPL_PREPROCESSING_MODE)
# define BOOST_MPL_PREPROCESSED_HEADER apply_fwd.hpp
# include <boost/mpl/aux_/include_preprocessed.hpp>
#else
# include <boost/mpl/limits/arity.hpp>
# include <boost/mpl/aux_/preprocessor/params.hpp>
# include <boost/mpl/aux_/preprocessor/default_params.hpp>
# include <boost/mpl/aux_/config/ctps.hpp>
# include <boost/mpl/aux_/nttp_decl.hpp>
# include <boost/preprocessor/comma_if.hpp>
# include <boost/preprocessor/iterate.hpp>
# include <boost/preprocessor/cat.hpp>
// agurt, 15/jan/02: top-level 'apply' template gives an ICE on MSVC
// (for known reasons)
#if BOOST_WORKAROUND(BOOST_MSVC, < 1300)
# define BOOST_MPL_CFG_NO_APPLY_TEMPLATE
#endif
namespace boost { namespace mpl {
// local macro, #undef-ined at the end of the header
# define AUX778076_APPLY_DEF_PARAMS(param, value) \
BOOST_MPL_PP_DEFAULT_PARAMS( \
BOOST_MPL_LIMIT_METAFUNCTION_ARITY \
, param \
, value \
) \
/**/
# define AUX778076_APPLY_N_COMMA_PARAMS(n, param) \
BOOST_PP_COMMA_IF(n) \
BOOST_MPL_PP_PARAMS(n, param) \
/**/
# if !defined(BOOST_MPL_CFG_NO_APPLY_TEMPLATE)
#if !defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION)
// forward declaration
template<
typename F, AUX778076_APPLY_DEF_PARAMS(typename T, na)
>
struct apply;
#else
namespace aux {
template< BOOST_AUX_NTTP_DECL(int, arity_) > struct apply_chooser;
}
#endif
# endif // BOOST_MPL_CFG_NO_APPLY_TEMPLATE
#define BOOST_PP_ITERATION_PARAMS_1 \
(3,(0, BOOST_MPL_LIMIT_METAFUNCTION_ARITY, <boost/mpl/apply_fwd.hpp>))
#include BOOST_PP_ITERATE()
# undef AUX778076_APPLY_N_COMMA_PARAMS
# undef AUX778076_APPLY_DEF_PARAMS
}}
#endif // BOOST_MPL_CFG_NO_PREPROCESSED_HEADERS
#endif // BOOST_MPL_APPLY_FWD_HPP_INCLUDED
///// iteration
#else
#define i_ BOOST_PP_FRAME_ITERATION(1)
template<
typename F AUX778076_APPLY_N_COMMA_PARAMS(i_, typename T)
>
struct BOOST_PP_CAT(apply,i_);
#undef i_
#endif // BOOST_PP_IS_ITERATING