Chris@16: 
Chris@16: #ifndef BOOST_MPL_STRING_HPP_INCLUDED
Chris@16: #define BOOST_MPL_STRING_HPP_INCLUDED
Chris@16: 
Chris@16: // Copyright Eric Niebler 2009
Chris@16: //
Chris@16: // Distributed under the Boost Software License, Version 1.0.
Chris@16: // (See accompanying file LICENSE_1_0.txt or copy at
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: //
Chris@16: // See http://www.boost.org/libs/mpl for documentation.
Chris@16: 
Chris@16: // $Id: string.hpp 49239 2009-04-01 09:10:26Z eric_niebler $
Chris@16: // $Date: 2009-04-01 02:10:26 -0700 (Wed, 1 Apr 2009) $
Chris@16: // $Revision: 49239 $
Chris@16: //
Chris@16: // Thanks to:
Chris@16: //   Dmitry Goncharov for porting this to the Sun compiler
Chris@16: 
Chris@16: #include <boost/config.hpp>
Chris@16: #include <boost/detail/workaround.hpp>
Chris@101: #include <boost/predef/other/endian.h>
Chris@16: #include <boost/mpl/limits/string.hpp>
Chris@16: #include <boost/mpl/if.hpp>
Chris@16: #include <boost/mpl/char.hpp>
Chris@16: #include <boost/mpl/copy.hpp>
Chris@16: #include <boost/mpl/size.hpp>
Chris@16: #include <boost/mpl/empty.hpp>
Chris@16: #include <boost/mpl/assert.hpp>
Chris@16: #include <boost/mpl/size_t.hpp>
Chris@16: #include <boost/mpl/begin_end.hpp>
Chris@16: #include <boost/mpl/joint_view.hpp>
Chris@16: #include <boost/mpl/insert_range.hpp>
Chris@16: #include <boost/mpl/back_inserter.hpp>
Chris@16: #include <boost/mpl/front_inserter.hpp>
Chris@16: #include <boost/mpl/iterator_range.hpp>
Chris@16: #include <boost/preprocessor/arithmetic/dec.hpp>
Chris@16: #include <boost/preprocessor/arithmetic/add.hpp>
Chris@16: #include <boost/preprocessor/arithmetic/div.hpp>
Chris@16: #include <boost/preprocessor/punctuation/comma_if.hpp>
Chris@16: #include <boost/preprocessor/repetition/repeat.hpp>
Chris@16: #include <boost/preprocessor/repetition/enum_params.hpp>
Chris@16: #include <boost/preprocessor/repetition/repeat_from_to.hpp>
Chris@16: #include <boost/preprocessor/repetition/enum_shifted_params.hpp>
Chris@16: #include <boost/preprocessor/repetition/enum_trailing_params.hpp>
Chris@16: #include <boost/preprocessor/repetition/enum_params_with_a_default.hpp>
Chris@16: 
Chris@16: #include <iterator> // for bidirectional_iterator_tag
Chris@16: #include <climits>
Chris@16: 
Chris@16: namespace boost { namespace mpl
Chris@16: {
Chris@16:     #define BOOST_MPL_STRING_MAX_PARAMS                                                             \
Chris@16:       BOOST_PP_DIV(BOOST_PP_ADD(BOOST_MPL_LIMIT_STRING_SIZE, 3), 4)
Chris@16: 
Chris@16:     // Low-level bit-twiddling is done by macros. Any implementation-defined behavior of
Chris@16:     // multi-character literals should be localized to these macros.
Chris@16: 
Chris@16:     #define BOOST_MPL_MULTICHAR_LENGTH(c)                                                           \
Chris@16:       (std::size_t)((c<CHAR_MIN) ? 4 : ((c>0xffffff)+(c>0xffff)+(c>0xff)+1))
Chris@16: 
Chris@101:     #if defined(BOOST_ENDIAN_LITTLE_BYTE) && defined(__SUNPRO_CC)
Chris@16: 
Chris@16:         #define BOOST_MPL_MULTICHAR_AT(c,i)                                                         \
Chris@16:           (char)(0xff&((unsigned)(c)>>(8*(std::size_t)(i))))
Chris@16: 
Chris@16:         #define BOOST_MPL_MULTICHAR_PUSH_BACK(c,i)                                                  \
Chris@16:           ((((unsigned char)(i))<<(BOOST_MPL_MULTICHAR_LENGTH(c)*8))|(unsigned)(c))
Chris@16: 
Chris@16:         #define BOOST_MPL_MULTICHAR_PUSH_FRONT(c,i)                                                 \
Chris@16:           (((unsigned)(c)<<8)|(unsigned char)(i))
Chris@16: 
Chris@16:         #define BOOST_MPL_MULTICHAR_POP_BACK(c)                                                     \
Chris@16:           (((1<<((BOOST_MPL_MULTICHAR_LENGTH(c)-1)*8))-1)&(unsigned)(c))
Chris@16: 
Chris@16:         #define BOOST_MPL_MULTICHAR_POP_FRONT(c)                                                    \
Chris@16:           ((unsigned)(c)>>8)
Chris@16: 
Chris@16:     #else
Chris@16: 
Chris@16:         #define BOOST_MPL_MULTICHAR_AT(c,i)                                                         \
Chris@16:           (char)(0xff&((unsigned)(c)>>(8*(BOOST_MPL_MULTICHAR_LENGTH(c)-(std::size_t)(i)-1))))
Chris@16: 
Chris@16:         #define BOOST_MPL_MULTICHAR_PUSH_BACK(c,i)                                                  \
Chris@16:           (((unsigned)(c)<<8)|(unsigned char)(i))
Chris@16: 
Chris@16:         #define BOOST_MPL_MULTICHAR_PUSH_FRONT(c,i)                                                 \
Chris@16:           ((((unsigned char)(i))<<(BOOST_MPL_MULTICHAR_LENGTH(c)*8))|(unsigned)(c))
Chris@16: 
Chris@16:         #define BOOST_MPL_MULTICHAR_POP_BACK(c)                                                     \
Chris@16:           ((unsigned)(c)>>8)
Chris@16: 
Chris@16:         #define BOOST_MPL_MULTICHAR_POP_FRONT(c)                                                    \
Chris@16:           (((1<<((BOOST_MPL_MULTICHAR_LENGTH(c)-1)*8))-1)&(unsigned)(c))
Chris@16: 
Chris@16:     #endif
Chris@16: 
Chris@16:     struct string_tag;
Chris@16:     struct string_iterator_tag;
Chris@16: 
Chris@16:     template<BOOST_PP_ENUM_PARAMS_WITH_A_DEFAULT(BOOST_MPL_STRING_MAX_PARAMS, int C, 0)>
Chris@16:     struct string;
Chris@16: 
Chris@16:     template<typename Sequence, int I, int J>
Chris@16:     struct string_iterator;
Chris@16: 
Chris@16:     template<typename Sequence>
Chris@16:     struct sequence_tag;
Chris@16: 
Chris@16:     template<typename Tag>
Chris@16:     struct size_impl;
Chris@16: 
Chris@16:     template<>
Chris@16:     struct size_impl<mpl::string_tag>
Chris@16:     {
Chris@16:         template<typename Sequence>
Chris@16:         struct apply;
Chris@16: 
Chris@16:         #define M0(z, n, data)                                                                      \
Chris@16:         + BOOST_MPL_MULTICHAR_LENGTH(BOOST_PP_CAT(C,n))
Chris@16: 
Chris@16:         #define M1(z, n, data)                                                                      \
Chris@16:         template<BOOST_PP_ENUM_PARAMS_Z(z, n, int C)>                                               \
Chris@16:         struct apply<mpl::string<BOOST_PP_ENUM_PARAMS_Z(z, n, C)> >                                 \
Chris@16:           : mpl::size_t<(0 BOOST_PP_REPEAT_ ## z(n, M0, ~))>                                        \
Chris@16:         {};
Chris@16: 
Chris@16:         BOOST_PP_REPEAT_FROM_TO(1, BOOST_PP_INC(BOOST_MPL_STRING_MAX_PARAMS), M1, ~)
Chris@16:         #undef M0
Chris@16:         #undef M1
Chris@16:     };
Chris@16: 
Chris@16:     template<>
Chris@16:     struct size_impl<mpl::string_tag>::apply<mpl::string<> >
Chris@16:       : mpl::size_t<0>
Chris@16:     {};
Chris@16: 
Chris@16:     template<typename Tag>
Chris@16:     struct begin_impl;
Chris@16: 
Chris@16:     template<>
Chris@16:     struct begin_impl<mpl::string_tag>
Chris@16:     {
Chris@16:         template<typename Sequence>
Chris@16:         struct apply
Chris@16:         {
Chris@16:             typedef mpl::string_iterator<Sequence, 0, 0> type;
Chris@16:         };
Chris@16:     };
Chris@16: 
Chris@16:     template<typename Tag>
Chris@16:     struct end_impl;
Chris@16: 
Chris@16:     template<>
Chris@16:     struct end_impl<mpl::string_tag>
Chris@16:     {
Chris@16:         template<typename Sequence>
Chris@16:         struct apply;
Chris@16: 
Chris@16:         #define M0(z,n,data)                                                                        \
Chris@16:         template<BOOST_PP_ENUM_PARAMS_Z(z, n, int C)>                                               \
Chris@16:         struct apply<mpl::string<BOOST_PP_ENUM_PARAMS_Z(z, n, C)> >                                 \
Chris@16:         {                                                                                           \
Chris@16:             typedef mpl::string_iterator<mpl::string<BOOST_PP_ENUM_PARAMS_Z(z, n, C)>, n, 0> type;  \
Chris@16:         };
Chris@16: 
Chris@16:         BOOST_PP_REPEAT_FROM_TO(1, BOOST_PP_INC(BOOST_MPL_STRING_MAX_PARAMS), M0, ~)
Chris@16:         #undef M0
Chris@16:     };
Chris@16: 
Chris@16:     template<>
Chris@16:     struct end_impl<mpl::string_tag>::apply<mpl::string<> >
Chris@16:     {
Chris@16:         typedef mpl::string_iterator<mpl::string<>, 0, 0> type;
Chris@16:     };
Chris@16: 
Chris@16:     template<typename Tag>
Chris@16:     struct push_back_impl;
Chris@16: 
Chris@16:     template<>
Chris@16:     struct push_back_impl<mpl::string_tag>
Chris@16:     {
Chris@16:         template<typename Sequence, typename Value, bool B = (4==BOOST_MPL_MULTICHAR_LENGTH(Sequence::back_))>
Chris@16:         struct apply
Chris@16:         {
Chris@16:             BOOST_MPL_ASSERT_MSG(
Chris@16:                 (BOOST_MPL_LIMIT_STRING_SIZE != mpl::size<Sequence>::type::value)
Chris@16:               , PUSH_BACK_FAILED_MPL_STRING_IS_FULL
Chris@16:               , (Sequence)
Chris@16:             );
Chris@16:             // If the above assertion didn't fire, then the string is sparse.
Chris@16:             // Repack the string and retry the push_back
Chris@16:             typedef
Chris@16:                 typename mpl::push_back<
Chris@16:                     typename mpl::copy<
Chris@16:                         Sequence
Chris@16:                       , mpl::back_inserter<mpl::string<> >
Chris@16:                     >::type
Chris@16:                   , Value
Chris@16:                 >::type
Chris@16:             type;
Chris@16:         };
Chris@16: 
Chris@16:         template<typename Value>
Chris@16:         struct apply<mpl::string<>, Value, false>
Chris@16:         {
Chris@16:             typedef mpl::string<(char)Value::value> type;
Chris@16:         };
Chris@16: 
Chris@16:         #define M0(z,n,data)                                                                        \
Chris@16:         template<BOOST_PP_ENUM_PARAMS_Z(z, n, int C), typename Value>                               \
Chris@16:         struct apply<mpl::string<BOOST_PP_ENUM_PARAMS_Z(z, n, C)>, Value, false>                    \
Chris@16:         {                                                                                           \
Chris@16:             typedef                                                                                 \
Chris@16:                 mpl::string<                                                                        \
Chris@16:                     BOOST_PP_ENUM_PARAMS_Z(z, BOOST_PP_DEC(n), C)                                   \
Chris@16:                     BOOST_PP_COMMA_IF(BOOST_PP_DEC(n))                                              \
Chris@16:                     ((unsigned)BOOST_PP_CAT(C,BOOST_PP_DEC(n))>0xffffff)                            \
Chris@16:                     ?BOOST_PP_CAT(C,BOOST_PP_DEC(n))                                                \
Chris@16:                     :BOOST_MPL_MULTICHAR_PUSH_BACK(BOOST_PP_CAT(C,BOOST_PP_DEC(n)), Value::value)   \
Chris@16:                   , ((unsigned)BOOST_PP_CAT(C,BOOST_PP_DEC(n))>0xffffff)                            \
Chris@16:                     ?(char)Value::value                                                             \
Chris@16:                     :0                                                                              \
Chris@16:                 >                                                                                   \
Chris@16:             type;                                                                                   \
Chris@16:         };
Chris@16: 
Chris@16:         BOOST_PP_REPEAT_FROM_TO(1, BOOST_MPL_STRING_MAX_PARAMS, M0, ~)
Chris@16:         #undef M0
Chris@16: 
Chris@16:         template<BOOST_PP_ENUM_PARAMS(BOOST_MPL_STRING_MAX_PARAMS, int C), typename Value>
Chris@16:         struct apply<mpl::string<BOOST_PP_ENUM_PARAMS(BOOST_MPL_STRING_MAX_PARAMS, C)>, Value, false>
Chris@16:         {
Chris@16:             typedef
Chris@16:                 mpl::string<
Chris@16:                     BOOST_PP_ENUM_PARAMS(BOOST_PP_DEC(BOOST_MPL_STRING_MAX_PARAMS), C)
Chris@16:                   , BOOST_MPL_MULTICHAR_PUSH_BACK(BOOST_PP_CAT(C,BOOST_PP_DEC(BOOST_MPL_STRING_MAX_PARAMS)), Value::value)
Chris@16:                 >
Chris@16:             type;
Chris@16:         };
Chris@16:     };
Chris@16: 
Chris@16:     template<typename Tag>
Chris@16:     struct has_push_back_impl;
Chris@16: 
Chris@16:     template<>
Chris@16:     struct has_push_back_impl<mpl::string_tag>
Chris@16:     {
Chris@16:         template<typename Sequence>
Chris@16:         struct apply
Chris@16:           : mpl::true_
Chris@16:         {};
Chris@16:     };
Chris@16: 
Chris@16:     template<typename Tag>
Chris@16:     struct pop_back_impl;
Chris@16: 
Chris@16:     template<>
Chris@16:     struct pop_back_impl<mpl::string_tag>
Chris@16:     {
Chris@16:         template<typename Sequence>
Chris@16:         struct apply;
Chris@16: 
Chris@16:         #define M0(z,n,data)                                                                        \
Chris@16:         template<BOOST_PP_ENUM_PARAMS_Z(z, n, int C)>                                               \
Chris@16:         struct apply<mpl::string<BOOST_PP_ENUM_PARAMS_Z(z, n, C)> >                                 \
Chris@16:         {                                                                                           \
Chris@16:             BOOST_MPL_ASSERT_MSG((C0 != 0), POP_BACK_FAILED_MPL_STRING_IS_EMPTY, (mpl::string<>));  \
Chris@16:             typedef                                                                                 \
Chris@16:                 mpl::string<                                                                        \
Chris@16:                     BOOST_PP_ENUM_PARAMS_Z(z, BOOST_PP_DEC(n), C)                                   \
Chris@16:                     BOOST_PP_COMMA_IF(BOOST_PP_DEC(n))                                              \
Chris@16:                     BOOST_MPL_MULTICHAR_POP_BACK(BOOST_PP_CAT(C,BOOST_PP_DEC(n)))                   \
Chris@16:                 >                                                                                   \
Chris@16:             type;                                                                                   \
Chris@16:         };
Chris@16: 
Chris@16:         BOOST_PP_REPEAT_FROM_TO(1, BOOST_PP_INC(BOOST_MPL_STRING_MAX_PARAMS), M0, ~)
Chris@16:         #undef M0
Chris@16:     };
Chris@16: 
Chris@16:     template<typename Tag>
Chris@16:     struct has_pop_back_impl;
Chris@16: 
Chris@16:     template<>
Chris@16:     struct has_pop_back_impl<mpl::string_tag>
Chris@16:     {
Chris@16:         template<typename Sequence>
Chris@16:         struct apply
Chris@16:           : mpl::true_
Chris@16:         {};
Chris@16:     };
Chris@16: 
Chris@16:     template<typename Tag>
Chris@16:     struct push_front_impl;
Chris@16: 
Chris@16:     template<>
Chris@16:     struct push_front_impl<mpl::string_tag>
Chris@16:     {
Chris@16:         template<typename Sequence, typename Value, bool B = (4==BOOST_MPL_MULTICHAR_LENGTH(Sequence::front_))>
Chris@16:         struct apply
Chris@16:         {
Chris@16:             BOOST_MPL_ASSERT_MSG(
Chris@16:                 (BOOST_MPL_LIMIT_STRING_SIZE != mpl::size<Sequence>::type::value)
Chris@16:               , PUSH_FRONT_FAILED_MPL_STRING_IS_FULL
Chris@16:               , (Sequence)
Chris@16:             );
Chris@16:             // If the above assertion didn't fire, then the string is sparse.
Chris@16:             // Repack the string and retry the push_front.
Chris@16:             typedef
Chris@16:                 typename mpl::push_front<
Chris@16:                     typename mpl::reverse_copy<
Chris@16:                         Sequence
Chris@16:                       , mpl::front_inserter<string<> >
Chris@16:                     >::type
Chris@16:                   , Value
Chris@16:                 >::type
Chris@16:             type;
Chris@16:         };
Chris@16: 
Chris@16:         #if !BOOST_WORKAROUND(__SUNPRO_CC, BOOST_TESTED_AT(0x590))
Chris@16:         template<typename Value>
Chris@16:         struct apply<mpl::string<>, Value, false>
Chris@16:         {
Chris@16:             typedef mpl::string<(char)Value::value> type;
Chris@16:         };
Chris@16:         #endif
Chris@16: 
Chris@16:         #define M0(z,n,data)                                                                        \
Chris@16:         template<BOOST_PP_ENUM_PARAMS_Z(z, n, int C), typename Value>                               \
Chris@16:         struct apply<mpl::string<BOOST_PP_ENUM_PARAMS_Z(z, n, C)>, Value, true>                     \
Chris@16:         {                                                                                           \
Chris@16:             typedef                                                                                 \
Chris@16:                 mpl::string<                                                                        \
Chris@16:                     (char)Value::value                                                              \
Chris@16:                     BOOST_PP_ENUM_TRAILING_PARAMS_Z(z, n, C)                                        \
Chris@16:                 >                                                                                   \
Chris@16:             type;                                                                                   \
Chris@16:         };
Chris@16: 
Chris@16:         BOOST_PP_REPEAT_FROM_TO(1, BOOST_MPL_STRING_MAX_PARAMS, M0, ~)
Chris@16:         #undef M0
Chris@16: 
Chris@16:         template<BOOST_PP_ENUM_PARAMS(BOOST_MPL_STRING_MAX_PARAMS, int C), typename Value>
Chris@16:         struct apply<mpl::string<BOOST_PP_ENUM_PARAMS(BOOST_MPL_STRING_MAX_PARAMS, C)>, Value, false>
Chris@16:         {
Chris@16:             typedef
Chris@16:                 mpl::string<
Chris@16:                     BOOST_MPL_MULTICHAR_PUSH_FRONT(C0, Value::value)
Chris@16:                   , BOOST_PP_ENUM_SHIFTED_PARAMS(BOOST_MPL_STRING_MAX_PARAMS, C)
Chris@16:                 >
Chris@16:             type0;
Chris@16: 
Chris@16:             #if BOOST_WORKAROUND(__SUNPRO_CC, BOOST_TESTED_AT(0x590))
Chris@16:             typedef
Chris@16:                 typename mpl::if_<
Chris@16:                     mpl::empty<mpl::string<BOOST_PP_ENUM_PARAMS(BOOST_MPL_STRING_MAX_PARAMS, C)> >
Chris@16:                   , mpl::string<(char)Value::value>
Chris@16:                   , type0
Chris@16:                 >::type
Chris@16:             type;
Chris@16:             #else
Chris@16:             typedef type0 type;
Chris@16:             #endif
Chris@16:         };
Chris@16:     };
Chris@16: 
Chris@16:     template<typename Tag>
Chris@16:     struct has_push_front_impl;
Chris@16: 
Chris@16:     template<>
Chris@16:     struct has_push_front_impl<mpl::string_tag>
Chris@16:     {
Chris@16:         template<typename Sequence>
Chris@16:         struct apply
Chris@16:           : mpl::true_
Chris@16:         {};
Chris@16:     };
Chris@16: 
Chris@16:     template<typename Tag>
Chris@16:     struct pop_front_impl;
Chris@16: 
Chris@16:     template<>
Chris@16:     struct pop_front_impl<mpl::string_tag>
Chris@16:     {
Chris@16:         template<typename Sequence, bool B = (1==BOOST_MPL_MULTICHAR_LENGTH(Sequence::front_))>
Chris@16:         struct apply;
Chris@16: 
Chris@16:         #define M0(z,n,data)                                                                        \
Chris@16:         template<BOOST_PP_ENUM_PARAMS_Z(z, n, int C)>                                               \
Chris@16:         struct apply<mpl::string<BOOST_PP_ENUM_PARAMS_Z(z, n, C)>, true>                            \
Chris@16:         {                                                                                           \
Chris@16:             BOOST_MPL_ASSERT_MSG((C0 != 0), POP_FRONT_FAILED_MPL_STRING_IS_EMPTY, (mpl::string<>)); \
Chris@16:             typedef                                                                                 \
Chris@16:                 mpl::string<BOOST_PP_ENUM_SHIFTED_PARAMS_Z(z, n, C)>                                \
Chris@16:             type;                                                                                   \
Chris@16:         };
Chris@16: 
Chris@16:         BOOST_PP_REPEAT_FROM_TO(1, BOOST_MPL_STRING_MAX_PARAMS, M0, ~)
Chris@16:         #undef M0
Chris@16: 
Chris@16:         template<BOOST_PP_ENUM_PARAMS(BOOST_MPL_STRING_MAX_PARAMS, int C)>
Chris@16:         struct apply<mpl::string<BOOST_PP_ENUM_PARAMS(BOOST_MPL_STRING_MAX_PARAMS, C)>, false>
Chris@16:         {
Chris@16:             typedef
Chris@16:                 mpl::string<
Chris@16:                     BOOST_MPL_MULTICHAR_POP_FRONT(C0)
Chris@16:                   , BOOST_PP_ENUM_SHIFTED_PARAMS(BOOST_MPL_STRING_MAX_PARAMS, C)
Chris@16:                 >
Chris@16:             type;
Chris@16:         };
Chris@16:     };
Chris@16: 
Chris@16:     template<typename Tag>
Chris@16:     struct has_pop_front_impl;
Chris@16: 
Chris@16:     template<>
Chris@16:     struct has_pop_front_impl<mpl::string_tag>
Chris@16:     {
Chris@16:         template<typename Sequence>
Chris@16:         struct apply
Chris@16:           : mpl::true_
Chris@16:         {};
Chris@16:     };
Chris@16: 
Chris@16:     template<typename Tag>
Chris@16:     struct insert_range_impl;
Chris@16: 
Chris@16:     template<>
Chris@16:     struct insert_range_impl<mpl::string_tag>
Chris@16:     {
Chris@16:         template<typename Sequence, typename Pos, typename Range>
Chris@16:         struct apply
Chris@16:           : mpl::copy<
Chris@16:                 mpl::joint_view<
Chris@16:                     mpl::iterator_range<
Chris@16:                         mpl::string_iterator<Sequence, 0, 0>
Chris@16:                       , Pos
Chris@16:                     >
Chris@16:                   , mpl::joint_view<
Chris@16:                         Range
Chris@16:                       , mpl::iterator_range<
Chris@16:                             Pos
Chris@16:                           , typename mpl::end<Sequence>::type
Chris@16:                         >
Chris@16:                     >
Chris@16:                 >
Chris@16:               , mpl::back_inserter<mpl::string<> >
Chris@16:             >
Chris@16:         {};
Chris@16:     };
Chris@16: 
Chris@16:     template<typename Tag>
Chris@16:     struct insert_impl;
Chris@16: 
Chris@16:     template<>
Chris@16:     struct insert_impl<mpl::string_tag>
Chris@16:     {
Chris@16:         template<typename Sequence, typename Pos, typename Value>
Chris@16:         struct apply
Chris@16:           : mpl::insert_range<Sequence, Pos, mpl::string<(char)Value::value> >
Chris@16:         {};
Chris@16:     };
Chris@16: 
Chris@16:     template<typename Tag>
Chris@16:     struct erase_impl;
Chris@16: 
Chris@16:     template<>
Chris@16:     struct erase_impl<mpl::string_tag>
Chris@16:     {
Chris@16:         template<typename Sequence, typename First, typename Last>
Chris@16:         struct apply
Chris@16:           : mpl::copy<
Chris@16:                 mpl::joint_view<
Chris@16:                     mpl::iterator_range<
Chris@16:                         mpl::string_iterator<Sequence, 0, 0>
Chris@16:                       , First
Chris@16:                     >
Chris@16:                   , mpl::iterator_range<
Chris@16:                         typename mpl::if_na<Last, typename mpl::next<First>::type>::type
Chris@16:                       , typename mpl::end<Sequence>::type
Chris@16:                     >
Chris@16:                 >
Chris@16:               , mpl::back_inserter<mpl::string<> >
Chris@16:             >
Chris@16:         {};
Chris@16:     };
Chris@16: 
Chris@16:     template<typename Tag>
Chris@16:     struct clear_impl;
Chris@16: 
Chris@16:     template<>
Chris@16:     struct clear_impl<mpl::string_tag>
Chris@16:     {
Chris@16:         template<typename>
Chris@16:         struct apply
Chris@16:         {
Chris@16:             typedef mpl::string<> type;
Chris@16:         };
Chris@16:     };
Chris@16: 
Chris@16:     #define M0(z, n, data)                                                                            \
Chris@16:     template<BOOST_PP_ENUM_PARAMS(BOOST_MPL_STRING_MAX_PARAMS, int C), int J>                         \
Chris@16:     struct string_iterator<mpl::string<BOOST_PP_ENUM_PARAMS(BOOST_MPL_STRING_MAX_PARAMS, C)>, n, J>   \
Chris@16:     {                                                                                                 \
Chris@16:         enum { eomc_ = (BOOST_MPL_MULTICHAR_LENGTH(BOOST_PP_CAT(C, n)) == J + 1) };                   \
Chris@16:         typedef mpl::string<BOOST_PP_ENUM_PARAMS(BOOST_MPL_STRING_MAX_PARAMS, C)> string;             \
Chris@16:         typedef std::bidirectional_iterator_tag category;                                             \
Chris@16:         typedef                                                                                       \
Chris@16:             mpl::string_iterator<string, n + eomc_, eomc_ ? 0 : J + 1>                                \
Chris@16:         next;                                                                                         \
Chris@16:         typedef                                                                                       \
Chris@16:             mpl::string_iterator<string, n, J - 1>                                                    \
Chris@16:         prior;                                                                                        \
Chris@16:         typedef mpl::char_<BOOST_MPL_MULTICHAR_AT(BOOST_PP_CAT(C, n), J)> type;                       \
Chris@16:     };                                                                                                \
Chris@16:     template<BOOST_PP_ENUM_PARAMS(BOOST_MPL_STRING_MAX_PARAMS, int C)>                                \
Chris@16:     struct string_iterator<mpl::string<BOOST_PP_ENUM_PARAMS(BOOST_MPL_STRING_MAX_PARAMS, C)>, n, 0>   \
Chris@16:     {                                                                                                 \
Chris@16:         enum { eomc_ = (BOOST_MPL_MULTICHAR_LENGTH(BOOST_PP_CAT(C, n)) == 1) };                       \
Chris@16:         typedef mpl::string<BOOST_PP_ENUM_PARAMS(BOOST_MPL_STRING_MAX_PARAMS, C)> string;             \
Chris@16:         typedef std::bidirectional_iterator_tag category;                                             \
Chris@16:         typedef                                                                                       \
Chris@16:             mpl::string_iterator<string, n + eomc_, !eomc_>                                           \
Chris@16:         next;                                                                                         \
Chris@16:         typedef                                                                                       \
Chris@16:             mpl::string_iterator<                                                                     \
Chris@16:                 string                                                                                \
Chris@16:               , n - 1                                                                                 \
Chris@16:               , BOOST_MPL_MULTICHAR_LENGTH(BOOST_PP_CAT(C, BOOST_PP_DEC(n))) - 1                      \
Chris@16:             >                                                                                         \
Chris@16:         prior;                                                                                        \
Chris@16:         typedef mpl::char_<BOOST_MPL_MULTICHAR_AT(BOOST_PP_CAT(C, n), 0)> type;                       \
Chris@16:     };
Chris@16: 
Chris@16:     BOOST_PP_REPEAT(BOOST_MPL_STRING_MAX_PARAMS, M0, ~)
Chris@16:     #undef M0
Chris@16: 
Chris@16:     template<BOOST_PP_ENUM_PARAMS(BOOST_MPL_STRING_MAX_PARAMS, int C)>
Chris@16:     struct string
Chris@16:     {
Chris@16:         /// INTERNAL ONLY
Chris@16:         enum
Chris@16:         {
Chris@16:             front_  = C0
Chris@16:           , back_   = BOOST_PP_CAT(C, BOOST_PP_DEC(BOOST_MPL_STRING_MAX_PARAMS))
Chris@16:         };
Chris@16: 
Chris@16:         typedef char        value_type;
Chris@16:         typedef string      type;
Chris@16:         typedef string_tag  tag;
Chris@16:     };
Chris@16: 
Chris@16:     namespace aux_
Chris@16:     {
Chris@16:         template<typename It, typename End>
Chris@16:         struct next_unless
Chris@16:           : mpl::next<It>
Chris@16:         {};
Chris@16: 
Chris@16:         template<typename End>
Chris@16:         struct next_unless<End, End>
Chris@16:         {
Chris@16:             typedef End type;
Chris@16:         };
Chris@16: 
Chris@16:         template<typename It, typename End>
Chris@16:         struct deref_unless
Chris@16:           : mpl::deref<It>
Chris@16:         {};
Chris@16: 
Chris@16:         template<typename End>
Chris@16:         struct deref_unless<End, End>
Chris@16:         {
Chris@16:             typedef mpl::char_<'\0'> type;
Chris@16:         };
Chris@16:     }
Chris@16: 
Chris@16:     template<typename Sequence>
Chris@16:     struct c_str
Chris@16:     {
Chris@16:         typedef typename mpl::end<Sequence>::type iend;
Chris@16:         typedef typename mpl::begin<Sequence>::type i0;
Chris@16:         #define M0(z, n, data)                                                                      \
Chris@16:         typedef                                                                                     \
Chris@16:             typename mpl::aux_::next_unless<BOOST_PP_CAT(i, n), iend>::type                         \
Chris@16:         BOOST_PP_CAT(i, BOOST_PP_INC(n));
Chris@16:         BOOST_PP_REPEAT(BOOST_MPL_LIMIT_STRING_SIZE, M0, ~)
Chris@16:         #undef M0
Chris@16: 
Chris@16:         typedef c_str type;
Chris@16:         static typename Sequence::value_type const value[BOOST_MPL_LIMIT_STRING_SIZE+1];
Chris@16:     };
Chris@16: 
Chris@16:     template<typename Sequence>
Chris@16:     typename Sequence::value_type const c_str<Sequence>::value[BOOST_MPL_LIMIT_STRING_SIZE+1] =
Chris@16:     {
Chris@16:         #define M0(z, n, data)                                                                      \
Chris@16:         mpl::aux_::deref_unless<BOOST_PP_CAT(i, n), iend>::type::value,
Chris@16:         BOOST_PP_REPEAT(BOOST_MPL_LIMIT_STRING_SIZE, M0, ~)
Chris@16:         #undef M0
Chris@16:         '\0'
Chris@16:     };
Chris@16: 
Chris@16: }} // namespace boost
Chris@16: 
Chris@16: #endif // BOOST_MPL_STRING_HPP_INCLUDED