3rdparty/boost/boost/parameter/preprocessor.hpp

   1 // Copyright Daniel Wallin 2006. Use, modification and distribution is
   2 // subject to the Boost Software License, Version 1.0. (See accompanying
   3 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   4
   5 #ifndef BOOST_PARAMETER_PREPROCESSOR_060206_HPP
   6 # define BOOST_PARAMETER_PREPROCESSOR_060206_HPP
   7
   8 # include <boost/parameter/parameters.hpp>
   9 # include <boost/parameter/binding.hpp>
  10 # include <boost/parameter/match.hpp>
  11
  12 # include <boost/parameter/aux_/parenthesized_type.hpp>
  13 # include <boost/parameter/aux_/cast.hpp>
  14 # include <boost/parameter/aux_/preprocessor/flatten.hpp>
  15
  16 # include <boost/preprocessor/repetition/repeat_from_to.hpp>
  17 # include <boost/preprocessor/comparison/equal.hpp>
  18 # include <boost/preprocessor/control/if.hpp>
  19 # include <boost/preprocessor/control/iif.hpp>
  20 # include <boost/preprocessor/control/expr_if.hpp>
  21 # include <boost/preprocessor/repetition/enum_params.hpp>
  22 # include <boost/preprocessor/repetition/enum_binary_params.hpp>
  23 # include <boost/preprocessor/repetition/enum_trailing.hpp>
  24 # include <boost/preprocessor/seq/first_n.hpp>
  25 # include <boost/preprocessor/seq/for_each_product.hpp>
  26 # include <boost/preprocessor/seq/for_each_i.hpp>
  27 # include <boost/preprocessor/tuple/elem.hpp>
  28 # include <boost/preprocessor/tuple/eat.hpp>
  29 # include <boost/preprocessor/seq/fold_left.hpp>
  30 # include <boost/preprocessor/seq/push_back.hpp>
  31 # include <boost/preprocessor/seq/size.hpp>
  32 # include <boost/preprocessor/seq/enum.hpp>
  33 # include <boost/preprocessor/seq/push_back.hpp>
  34
  35 # include <boost/preprocessor/detail/is_nullary.hpp>
  36
  37 # include <boost/mpl/always.hpp>
  38 # include <boost/mpl/apply_wrap.hpp>
  39
  40 namespace boost { namespace parameter { namespace aux {
  41
  42 #  if ! defined(BOOST_NO_SFINAE) && ! BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x592))
  43
  44 // Given Match, which is "void x" where x is an argument matching
  45 // criterion, extract a corresponding MPL predicate.
  46 template <class Match>
  47 struct unwrap_predicate;
  48
  49 // Match anything
  50 template <>
  51 struct unwrap_predicate<void*>
  52 {
  53     typedef mpl::always<mpl::true_> type;
  54 };
  55
  56 #if BOOST_WORKAROUND(__SUNPRO_CC, BOOST_TESTED_AT(0x580))
  57
  58 typedef void* voidstar;
  59
  60 // A matching predicate is explicitly specified
  61 template <class Predicate>
  62 struct unwrap_predicate<voidstar (Predicate)>
  63 {
  64     typedef Predicate type;
  65 };
  66
  67 #else
  68
  69 // A matching predicate is explicitly specified
  70 template <class Predicate>
  71 struct unwrap_predicate<void *(Predicate)>
  72 {
  73     typedef Predicate type;
  74 };
  75
  76 #endif
  77
  78
  79 // A type to which the argument is supposed to be convertible is
  80 // specified
  81 template <class Target>
  82 struct unwrap_predicate<void (Target)>
  83 {
  84     typedef is_convertible<mpl::_, Target> type;
  85 };
  86
  87 // Recast the ParameterSpec's nested match metafunction as a free metafunction
  88 template <
  89     class Parameters
  90   , BOOST_PP_ENUM_BINARY_PARAMS(
  91         BOOST_PARAMETER_MAX_ARITY, class A, = boost::parameter::void_ BOOST_PP_INTERCEPT
  92     )
  93 >
  94 struct match
  95   : Parameters::template match<
  96         BOOST_PP_ENUM_PARAMS(BOOST_PARAMETER_MAX_ARITY, A)
  97     >
  98 {};
  99 # endif
 100
 101 # undef false_
 102
 103 template <
 104     class Parameters
 105   , BOOST_PP_ENUM_BINARY_PARAMS(
 106         BOOST_PARAMETER_MAX_ARITY, class A, = boost::parameter::void_ BOOST_PP_INTERCEPT
 107     )
 108 >
 109 struct argument_pack
 110 {
 111     typedef typename make_arg_list<
 112         typename BOOST_PARAMETER_build_arg_list(
 113             BOOST_PARAMETER_MAX_ARITY, make_items, typename Parameters::parameter_spec, A
 114         )::type
 115       , typename Parameters::deduced_list
 116       , tag_keyword_arg
 117       , mpl::false_
 118     >::type result;
 119     typedef typename mpl::first<result>::type type;
 120 };
 121
 122 // Works around VC6 problem where it won't accept rvalues.
 123 template <class T>
 124 T& as_lvalue(T& value, long)
 125 {
 126     return value;
 127 }
 128
 129 template <class T>
 130 T const& as_lvalue(T const& value, int)
 131 {
 132     return value;
 133 }
 134
 135
 136 # if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564))
 137
 138 template <class Predicate, class T, class Args>
 139 struct apply_predicate
 140 {
 141     BOOST_MPL_ASSERT((
 142         mpl::and_<mpl::false_,T>
 143     ));
 144
 145     typedef typename mpl::if_<
 146         typename mpl::apply2<Predicate,T,Args>::type
 147       , char
 148       , int
 149     >::type type;
 150 };
 151
 152 template <class P>
 153 struct funptr_predicate
 154 {
 155     static P p;
 156
 157     template <class T, class Args, class P0>
 158     static typename apply_predicate<P0,T,Args>::type
 159     check_predicate(type<T>, Args*, void**(*)(P0));
 160
 161     template <class T, class Args, class P0>
 162     static typename mpl::if_<
 163         is_convertible<T,P0>
 164       , char
 165       , int
 166      >::type check_predicate(type<T>, Args*, void*(*)(P0));
 167
 168     template <class T, class Args>
 169     struct apply
 170     {
 171         BOOST_STATIC_CONSTANT(bool, result =
 172             sizeof(check_predicate(boost::type<T>(), (Args*)0, &p)) == 1
 173         );
 174
 175         typedef mpl::bool_<apply<T,Args>::result> type;
 176     };
 177 };
 178
 179 template <>
 180 struct funptr_predicate<void**>
 181   : mpl::always<mpl::true_>
 182 {};
 183
 184 # endif
 185
 186 }}} // namespace boost::parameter::aux
 187
 188 # if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564))
 189 // From Paul Mensonides
 190 #  define BOOST_PARAMETER_IS_NULLARY(x) \
 191     BOOST_PP_SPLIT(1, BOOST_PARAMETER_IS_NULLARY_C x BOOST_PP_COMMA() 0) \
 192     /**/
 193 #  define BOOST_PARAMETER_IS_NULLARY_C() \
 194     ~, 1 BOOST_PP_RPAREN() \
 195     BOOST_PP_TUPLE_EAT(2) BOOST_PP_LPAREN() ~ \
 196     /**/
 197 # else
 198 #  define BOOST_PARAMETER_IS_NULLARY(x) BOOST_PP_IS_NULLARY(x)
 199 # endif
 200
 201 # define BOOST_PARAMETER_MEMBER_FUNCTION_CHECK_STATIC_static ()
 202 # define BOOST_PARAMETER_MEMBER_FUNCTION_IS_STATIC(name) \
 203     BOOST_PARAMETER_IS_NULLARY( \
 204         BOOST_PP_CAT(BOOST_PARAMETER_MEMBER_FUNCTION_CHECK_STATIC_,name) \
 205     )
 206
 207 # if !defined(BOOST_MSVC)
 208 #  define BOOST_PARAMETER_MEMBER_FUNCTION_STRIP_STATIC_static
 209 #  define BOOST_PARAMETER_MEMBER_FUNCTION_STRIP_STATIC(name) \
 210     BOOST_PP_CAT(BOOST_PARAMETER_MEMBER_FUNCTION_STRIP_STATIC_, name)
 211 # else
 212 // Workaround for MSVC preprocessor.
 213 //
 214 // When stripping static from "static f", msvc will produce
 215 // " f". The leading whitespace doesn't go away when pasting
 216 // the token with something else, so this thing is a hack to
 217 // strip the whitespace.
 218 #  define BOOST_PARAMETER_MEMBER_FUNCTION_STRIP_STATIC_static (
 219 #  define BOOST_PARAMETER_MEMBER_FUNCTION_STRIP_STATIC_AUX(name) \
 220     BOOST_PP_CAT(BOOST_PARAMETER_MEMBER_FUNCTION_STRIP_STATIC_, name))
 221 #  define BOOST_PARAMETER_MEMBER_FUNCTION_STRIP_STATIC(name) \
 222     BOOST_PP_SEQ_HEAD( \
 223         BOOST_PARAMETER_MEMBER_FUNCTION_STRIP_STATIC_AUX(name) \
 224     )
 225 # endif
 226
 227 # define BOOST_PARAMETER_MEMBER_FUNCTION_STATIC(name) \
 228     BOOST_PP_EXPR_IF( \
 229         BOOST_PARAMETER_MEMBER_FUNCTION_IS_STATIC(name) \
 230       , static \
 231     )
 232
 233 # define BOOST_PARAMETER_MEMBER_FUNCTION_NAME(name) \
 234     BOOST_PP_IF( \
 235         BOOST_PARAMETER_MEMBER_FUNCTION_IS_STATIC(name) \
 236       , BOOST_PARAMETER_MEMBER_FUNCTION_STRIP_STATIC \
 237       , name BOOST_PP_TUPLE_EAT(1) \
 238     )(name)
 239
 240 // Calculates [begin, end) arity range.
 241
 242 # define BOOST_PARAMETER_ARITY_RANGE_M_optional(state) state
 243 # define BOOST_PARAMETER_ARITY_RANGE_M_deduced_optional(state) state
 244 # define BOOST_PARAMETER_ARITY_RANGE_M_required(state) BOOST_PP_INC(state)
 245 # define BOOST_PARAMETER_ARITY_RANGE_M_deduced_required(state) BOOST_PP_INC(state)
 246
 247 # define BOOST_PARAMETER_ARITY_RANGE_M(s, state, x) \
 248     BOOST_PP_CAT( \
 249         BOOST_PARAMETER_ARITY_RANGE_M_ \
 250       , BOOST_PARAMETER_FN_ARG_QUALIFIER(x) \
 251     )(state)
 252 /**/
 253
 254 # define BOOST_PARAMETER_ARITY_RANGE(args) \
 255     ( \
 256         BOOST_PP_SEQ_FOLD_LEFT(BOOST_PARAMETER_ARITY_RANGE_M, 0, args) \
 257       , BOOST_PP_INC(BOOST_PP_SEQ_SIZE(args)) \
 258     )
 259 /**/
 260
 261 // Accessor macros for the argument specs tuple.
 262 # define BOOST_PARAMETER_FN_ARG_QUALIFIER(x) \
 263     BOOST_PP_TUPLE_ELEM(4,0,x)
 264 /**/
 265
 266 # define BOOST_PARAMETER_FN_ARG_NAME(x) \
 267     BOOST_PP_TUPLE_ELEM(4,1,x)
 268 /**/
 269
 270 # define BOOST_PARAMETER_FN_ARG_PRED(x) \
 271     BOOST_PP_TUPLE_ELEM(4,2,x)
 272 /**/
 273
 274 # define BOOST_PARAMETER_FN_ARG_DEFAULT(x) \
 275     BOOST_PP_TUPLE_ELEM(4,3,x)
 276 /**/
 277
 278 # define BOOST_PARAMETETER_FUNCTION_EAT_KEYWORD_QUALIFIER_out(x)
 279 # define BOOST_PARAMETETER_FUNCTION_EAT_KEYWORD_QUALIFIER_in_out(x)
 280
 281 // Returns 1 if x is either "out(k)" or "in_out(k)".
 282 # define BOOST_PARAMETER_FUNCTION_IS_KEYWORD_QUALIFIER(x) \
 283     BOOST_PP_IS_EMPTY( \
 284         BOOST_PP_CAT(BOOST_PARAMETETER_FUNCTION_EAT_KEYWORD_QUALIFIER_, x) \
 285     ) \
 286 /**/
 287
 288 # define BOOST_PARAMETETER_FUNCTION_GET_KEYWORD_QUALIFIER_out(x) x
 289 # define BOOST_PARAMETETER_FUNCTION_GET_KEYWORD_QUALIFIER_in_out(x) x
 290 # define BOOST_PARAMETER_FUNCTION_KEYWORD_GET(x) \
 291     BOOST_PP_CAT(BOOST_PARAMETETER_FUNCTION_GET_KEYWORD_QUALIFIER_, x)
 292 /**/
 293
 294 // Returns the keyword of x, where x is either a keyword qualifier
 295 // or a keyword.
 296 //
 297 //   k => k
 298 //   out(k) => k
 299 //   in_out(k) => k
 300 //
 301 # define BOOST_PARAMETER_FUNCTION_KEYWORD(x) \
 302     BOOST_PP_IF( \
 303         BOOST_PARAMETER_FUNCTION_IS_KEYWORD_QUALIFIER(x) \
 304       , BOOST_PARAMETER_FUNCTION_KEYWORD_GET \
 305       , x BOOST_PP_TUPLE_EAT(1) \
 306     )(x)
 307 /**/
 308
 309 # define BOOST_PARAMETER_FN_ARG_KEYWORD(x) \
 310     BOOST_PARAMETER_FUNCTION_KEYWORD( \
 311         BOOST_PARAMETER_FN_ARG_NAME(x) \
 312     )
 313
 314 // Builds forwarding functions.
 315
 316 # define BOOST_PARAMETER_FUNCTION_FWD_FUNCTION_TEMPLATE_Z(z, n) \
 317     template<BOOST_PP_ENUM_PARAMS_Z(z, n, class ParameterArgumentType)>
 318 /**/
 319
 320 # if ! defined(BOOST_NO_SFINAE) && ! BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x592))
 321 #  define BOOST_PARAMETER_FUNCTION_FWD_MATCH_Z(z, name, parameters, n) \
 322     , typename boost::parameter::aux::match< \
 323           parameters, BOOST_PP_ENUM_PARAMS(n, ParameterArgumentType) \
 324       >::type = parameters()
 325 # else
 326 #  define BOOST_PARAMETER_FUNCTION_FWD_MATCH_Z(z, name, parameters, n)
 327 # endif
 328 /**/
 329
 330 # define BOOST_PARAMETER_FUNCTION_PARAMETERS_NAME(base) \
 331     BOOST_PP_CAT( \
 332         boost_param_parameters_ \
 333       , BOOST_PP_CAT(__LINE__, BOOST_PARAMETER_MEMBER_FUNCTION_NAME(base)) \
 334     )
 335
 336 // Produce a name for a result type metafunction for the function
 337 // named base
 338 # define BOOST_PARAMETER_FUNCTION_RESULT_NAME(base) \
 339     BOOST_PP_CAT( \
 340         boost_param_result_ \
 341       , BOOST_PP_CAT(__LINE__,BOOST_PARAMETER_MEMBER_FUNCTION_NAME(base)) \
 342     )
 343
 344 // Can't do boost_param_impl_ ## basee because base might start with an underscore
 345 // daniel: what? how is that relevant? the reason for using CAT() is to make sure
 346 // base is expanded. i'm not sure we need to here, but it's more stable to do it.
 347 # define BOOST_PARAMETER_IMPL(base) \
 348     BOOST_PP_CAT(boost_param_impl,BOOST_PARAMETER_MEMBER_FUNCTION_NAME(base))
 349
 350 # define BOOST_PARAMETER_FUNCTION_FWD_FUNCTION00(z, n, r, data, elem) \
 351     BOOST_PP_IF( \
 352         n \
 353       , BOOST_PARAMETER_FUNCTION_FWD_FUNCTION_TEMPLATE_Z, BOOST_PP_TUPLE_EAT(2) \
 354     )(z,n) \
 355     BOOST_PARAMETER_MEMBER_FUNCTION_STATIC(BOOST_PP_TUPLE_ELEM(7,3,data)) \
 356     inline \
 357     BOOST_PP_EXPR_IF(n, typename) \
 358         BOOST_PARAMETER_FUNCTION_RESULT_NAME(BOOST_PP_TUPLE_ELEM(7,3,data))<   \
 359         BOOST_PP_EXPR_IF(n, typename) \
 360         boost::parameter::aux::argument_pack< \
 361             BOOST_PARAMETER_FUNCTION_PARAMETERS_NAME(BOOST_PP_TUPLE_ELEM(7,3,data)) \
 362             BOOST_PP_COMMA_IF(n) \
 363             BOOST_PP_IF( \
 364                 n, BOOST_PP_SEQ_ENUM, BOOST_PP_TUPLE_EAT(1) \
 365             )(elem) \
 366         >::type \
 367     >::type \
 368     BOOST_PARAMETER_MEMBER_FUNCTION_NAME(BOOST_PP_TUPLE_ELEM(7,3,data))( \
 369         BOOST_PP_IF( \
 370             n \
 371           , BOOST_PP_SEQ_FOR_EACH_I_R \
 372           , BOOST_PP_TUPLE_EAT(4) \
 373         )( \
 374             r \
 375           , BOOST_PARAMETER_FUNCTION_ARGUMENT \
 376           , ~ \
 377           , elem \
 378         ) \
 379         BOOST_PP_IF(n, BOOST_PARAMETER_FUNCTION_FWD_MATCH_Z, BOOST_PP_TUPLE_EAT(4))( \
 380             z \
 381           , BOOST_PP_TUPLE_ELEM(7,3,data) \
 382           , BOOST_PARAMETER_FUNCTION_PARAMETERS_NAME(BOOST_PP_TUPLE_ELEM(7,3,data)) \
 383           , n \
 384         ) \
 385     ) BOOST_PP_EXPR_IF(BOOST_PP_TUPLE_ELEM(7,4,data), const) \
 386     { \
 387         return BOOST_PARAMETER_IMPL(BOOST_PP_TUPLE_ELEM(7,3,data))( \
 388             BOOST_PARAMETER_FUNCTION_PARAMETERS_NAME(BOOST_PP_TUPLE_ELEM(7,3,data))()( \
 389                 BOOST_PP_ENUM_PARAMS_Z(z, n, a) \
 390             ) \
 391         ); \
 392     }
 393 /**/
 394
 395 # define BOOST_PARAMETER_FUNCTION_FWD_FUNCTION0(r, data, elem) \
 396     BOOST_PARAMETER_FUNCTION_FWD_FUNCTION00( \
 397         BOOST_PP_TUPLE_ELEM(7,0,data) \
 398       , BOOST_PP_TUPLE_ELEM(7,1,data) \
 399       , r \
 400       , data \
 401       , elem \
 402     )
 403 /**/
 404
 405 # define BOOST_PARAMETER_FUNCTION_FWD_FUNCTION_ARITY_0(z, n, data) \
 406     BOOST_PARAMETER_FUNCTION_FWD_FUNCTION00( \
 407         z, n, BOOST_PP_DEDUCE_R() \
 408       , (z, n, BOOST_PP_TUPLE_REM(5) data) \
 409       , ~ \
 410     )
 411 /**/
 412
 413 # define BOOST_PARAMETER_FUNCTION_FWD_FUNCTION_ARITY_N(z, n, data) \
 414     BOOST_PP_SEQ_FOR_EACH( \
 415         BOOST_PARAMETER_FUNCTION_FWD_FUNCTION0 \
 416       , (z, n, BOOST_PP_TUPLE_REM(5) data) \
 417       , BOOST_PP_SEQ_FOR_EACH_PRODUCT( \
 418             BOOST_PARAMETER_FUNCTION_FWD_PRODUCT \
 419           , BOOST_PP_SEQ_FIRST_N( \
 420                 n, BOOST_PP_TUPLE_ELEM(5,3,data) \
 421             ) \
 422         ) \
 423     )
 424 /**/
 425
 426 # define BOOST_PARAMETER_FUNCTION_FWD_FUNCTION(z, n, data) \
 427     BOOST_PP_IF( \
 428         n \
 429       , BOOST_PARAMETER_FUNCTION_FWD_FUNCTION_ARITY_N \
 430       , BOOST_PARAMETER_FUNCTION_FWD_FUNCTION_ARITY_0 \
 431     )(z,n,data) \
 432 /**/
 433
 434 # define BOOST_PARAMETER_FUNCTION_FWD_FUNCTIONS0( \
 435     result,name,args,const_,combinations,range \
 436 ) \
 437     BOOST_PP_REPEAT_FROM_TO( \
 438         BOOST_PP_TUPLE_ELEM(2,0,range), BOOST_PP_TUPLE_ELEM(2,1,range) \
 439       , BOOST_PARAMETER_FUNCTION_FWD_FUNCTION \
 440       , (result,name,const_,combinations,BOOST_PP_TUPLE_ELEM(2,1,range)) \
 441     )
 442 /**/
 443
 444 # define BOOST_PARAMETER_FUNCTION_FWD_FUNCTIONS(result,name,args, const_, combinations) \
 445     BOOST_PARAMETER_FUNCTION_FWD_FUNCTIONS0( \
 446         result, name, args, const_, combinations, BOOST_PARAMETER_ARITY_RANGE(args) \
 447     )
 448 /**/
 449
 450 // Builds boost::parameter::parameters<> specialization
 451 #  define BOOST_PARAMETER_FUNCTION_PARAMETERS_QUALIFIER_optional(tag) \
 452     optional<tag
 453
 454 #  define BOOST_PARAMETER_FUNCTION_PARAMETERS_QUALIFIER_required(tag) \
 455     required<tag
 456
 457 #  define BOOST_PARAMETER_FUNCTION_PARAMETERS_QUALIFIER_deduced_optional(tag) \
 458     optional<boost::parameter::deduced<tag>
 459
 460 #  define BOOST_PARAMETER_FUNCTION_PARAMETERS_QUALIFIER_deduced_required(tag) \
 461     required<boost::parameter::deduced<tag>
 462
 463 # if !BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564))
 464
 465 #  define BOOST_PARAMETER_FUNCTION_PARAMETERS_M(r,tag_namespace,i,elem) \
 466     BOOST_PP_COMMA_IF(i) \
 467     boost::parameter::BOOST_PP_CAT( \
 468         BOOST_PARAMETER_FUNCTION_PARAMETERS_QUALIFIER_ \
 469       , BOOST_PARAMETER_FN_ARG_QUALIFIER(elem) \
 470     )( \
 471         tag_namespace::BOOST_PARAMETER_FUNCTION_KEYWORD( \
 472             BOOST_PARAMETER_FN_ARG_KEYWORD(elem) \
 473         ) \
 474     ) \
 475       , typename boost::parameter::aux::unwrap_predicate< \
 476             void BOOST_PARAMETER_FN_ARG_PRED(elem) \
 477         >::type \
 478     >
 479 # elif BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564))
 480 #  define BOOST_PARAMETER_FUNCTION_PARAMETERS_M(r,tag_namespace,i,elem) \
 481     BOOST_PP_COMMA_IF(i) \
 482     boost::parameter::BOOST_PP_CAT( \
 483         BOOST_PARAMETER_FUNCTION_PARAMETERS_QUALIFIER_ \
 484       , BOOST_PARAMETER_FN_ARG_QUALIFIER(elem) \
 485     )( \
 486         tag_namespace::BOOST_PARAMETER_FUNCTION_KEYWORD( \
 487             BOOST_PARAMETER_FN_ARG_KEYWORD(elem) \
 488         ) \
 489     ) \
 490       , boost::mpl::always<boost::mpl::true_> \
 491     >
 492 # endif
 493
 494 # define BOOST_PARAMETER_FUNCTION_PARAMETERS(tag_namespace, base, args)             \
 495     template <class BoostParameterDummy>                                            \
 496     struct BOOST_PP_CAT(                                                            \
 497             BOOST_PP_CAT(boost_param_params_, __LINE__)                             \
 498           , BOOST_PARAMETER_MEMBER_FUNCTION_NAME(base)                              \
 499     ) : boost::parameter::parameters<                                               \
 500             BOOST_PP_SEQ_FOR_EACH_I(                                                \
 501                 BOOST_PARAMETER_FUNCTION_PARAMETERS_M, tag_namespace, args          \
 502             )                                                                       \
 503         >                                                                           \
 504     {};                                                                             \
 505                                                                                     \
 506     typedef BOOST_PP_CAT( \
 507             BOOST_PP_CAT(boost_param_params_, __LINE__) \
 508           , BOOST_PARAMETER_MEMBER_FUNCTION_NAME(base) \
 509     )<int>
 510
 511 // Defines result type metafunction
 512 # define BOOST_PARAMETER_FUNCTION_RESULT_ARG(z, _, i, x) \
 513     BOOST_PP_COMMA_IF(i) class BOOST_PP_TUPLE_ELEM(3,1,x)
 514 /**/
 515
 516 # define BOOST_PARAMETER_FUNCTION_RESULT_(result, name, args)                                   \
 517     template <class Args>                                                                       \
 518     struct BOOST_PARAMETER_FUNCTION_RESULT_NAME(name)                                           \
 519     {                                                                                           \
 520         typedef typename BOOST_PARAMETER_PARENTHESIZED_TYPE(result) type;                       \
 521     };
 522
 523 // Defines implementation function
 524 # define BOOST_PARAMETER_FUNCTION_IMPL_HEAD(name)           \
 525     template <class Args>                                   \
 526     typename BOOST_PARAMETER_FUNCTION_RESULT_NAME(name)<    \
 527        Args                                                 \
 528     >::type BOOST_PARAMETER_IMPL(name)(Args const& args)
 529
 530 # define BOOST_PARAMETER_FUNCTION_IMPL_FWD(name) \
 531     BOOST_PARAMETER_FUNCTION_IMPL_HEAD(name);
 532 /**/
 533
 534 # define BOOST_PARAMETER_FUNCTION_SPLIT_ARG_required(state, arg) \
 535     ( \
 536         BOOST_PP_INC(BOOST_PP_TUPLE_ELEM(4, 0, state)) \
 537       , BOOST_PP_SEQ_PUSH_BACK(BOOST_PP_TUPLE_ELEM(4, 1, state), arg) \
 538       , BOOST_PP_TUPLE_ELEM(4, 2, state) \
 539       , BOOST_PP_TUPLE_ELEM(4, 3, state) \
 540     )
 541
 542 # define BOOST_PARAMETER_FUNCTION_SPLIT_ARG_deduced_required(state, arg) \
 543     BOOST_PARAMETER_FUNCTION_SPLIT_ARG_required(state, arg)
 544
 545 # define BOOST_PARAMETER_FUNCTION_SPLIT_ARG_optional(state, arg) \
 546     ( \
 547         BOOST_PP_TUPLE_ELEM(4, 0, state) \
 548       , BOOST_PP_TUPLE_ELEM(4, 1, state) \
 549       , BOOST_PP_INC(BOOST_PP_TUPLE_ELEM(4, 2, state)) \
 550       , BOOST_PP_SEQ_PUSH_BACK(BOOST_PP_TUPLE_ELEM(4, 3, state), arg) \
 551     )
 552
 553 # define BOOST_PARAMETER_FUNCTION_SPLIT_ARG_deduced_optional(state, arg) \
 554     BOOST_PARAMETER_FUNCTION_SPLIT_ARG_optional(state, arg)
 555
 556 # define BOOST_PARAMETER_FUNCTION_SPLIT_ARG(s, state, arg) \
 557     BOOST_PP_CAT( \
 558         BOOST_PARAMETER_FUNCTION_SPLIT_ARG_ \
 559       , BOOST_PARAMETER_FN_ARG_QUALIFIER(arg) \
 560     )(state, arg)
 561
 562 // Returns (required_count, required, optional_count, optionals) tuple
 563 # define BOOST_PARAMETER_FUNCTION_SPLIT_ARGS(args) \
 564     BOOST_PP_SEQ_FOLD_LEFT( \
 565         BOOST_PARAMETER_FUNCTION_SPLIT_ARG \
 566       , (0,BOOST_PP_SEQ_NIL, 0,BOOST_PP_SEQ_NIL) \
 567       , args \
 568     )
 569
 570 # define BOOST_PARAMETER_FUNCTION_DEFAULT_FUNCTION_ARG_NAME(keyword) \
 571     BOOST_PP_CAT(BOOST_PP_CAT(keyword,_),type)
 572
 573 // Helpers used as parameters to BOOST_PARAMETER_FUNCTION_DEFAULT_ARGUMENTS.
 574 # define BOOST_PARAMETER_FUNCTION_DEFAULT_FUNCTION_TEMPLATE_ARG(r, _, arg) \
 575     , class BOOST_PARAMETER_FUNCTION_DEFAULT_FUNCTION_ARG_NAME( \
 576               BOOST_PARAMETER_FN_ARG_KEYWORD(arg) \
 577       )
 578
 579 # define BOOST_PARAMETER_FUNCTION_DEFAULT_FUNCTION_ARG(r, _, arg) \
 580     , BOOST_PARAMETER_FUNCTION_DEFAULT_FUNCTION_ARG_NAME( \
 581               BOOST_PARAMETER_FN_ARG_KEYWORD(arg) \
 582       )& BOOST_PARAMETER_FN_ARG_KEYWORD(arg)
 583
 584 # define BOOST_PARAMETER_FUNCTION_DEFAULT_FUNCTION_PARAMETER(r, _, arg) \
 585     , BOOST_PARAMETER_FN_ARG_KEYWORD(arg)
 586
 587 // Produces a name for the dispatch functions.
 588 # define BOOST_PARAMETER_FUNCTION_DEFAULT_NAME(name) \
 589     BOOST_PP_CAT( \
 590         boost_param_default_ \
 591       , BOOST_PP_CAT(__LINE__, BOOST_PARAMETER_MEMBER_FUNCTION_NAME(name)) \
 592     )
 593
 594 // Helper macro used below to produce lists based on the keyword argument
 595 // names. macro is applied to every element. n is the number of
 596 // optional arguments that should be included.
 597 # define BOOST_PARAMETER_FUNCTION_DEFAULT_ARGUMENTS(macro, n, split_args) \
 598     BOOST_PP_SEQ_FOR_EACH( \
 599         macro \
 600       , ~ \
 601       , BOOST_PP_TUPLE_ELEM(4,1,split_args) \
 602     ) \
 603     BOOST_PP_SEQ_FOR_EACH( \
 604         macro \
 605       , ~ \
 606       , BOOST_PP_SEQ_FIRST_N( \
 607           BOOST_PP_SUB(BOOST_PP_TUPLE_ELEM(4,2,split_args), n) \
 608         , BOOST_PP_TUPLE_ELEM(4,3,split_args) \
 609         ) \
 610     )
 611
 612 // Generates a keyword | default expression.
 613 # define BOOST_PARAMETER_FUNCTION_DEFAULT_EVAL_DEFAULT(arg, tag_namespace) \
 614     boost::parameter::keyword< \
 615         tag_namespace::BOOST_PARAMETER_FN_ARG_KEYWORD(arg) \
 616     >::instance | boost::parameter::aux::use_default_tag()
 617
 618 # define BOOST_PARAMETER_FUNCTION_DEFAULT_FUNCTION_GET_ARG(arg, tag_ns) \
 619     BOOST_PARAMETER_FUNCTION_CAST( \
 620         args[ \
 621             BOOST_PARAMETER_FUNCTION_DEFAULT_EVAL_DEFAULT( \
 622                 arg, tag_ns \
 623             ) \
 624         ] \
 625       , BOOST_PARAMETER_FN_ARG_PRED(arg) \
 626       , Args \
 627     )
 628
 629 # define BOOST_PARAMETER_FUNCTION_DEFAULT_FUNCTION_BODY(name, n, split_args, tag_namespace) \
 630     { \
 631         return BOOST_PARAMETER_FUNCTION_DEFAULT_NAME(name)( \
 632             (ResultType(*)())0 \
 633           , args \
 634           , 0L \
 635             BOOST_PARAMETER_FUNCTION_DEFAULT_ARGUMENTS( \
 636                 BOOST_PARAMETER_FUNCTION_DEFAULT_FUNCTION_PARAMETER \
 637               , n \
 638               , split_args \
 639             ) \
 640           , BOOST_PARAMETER_FUNCTION_DEFAULT_FUNCTION_GET_ARG( \
 641                 BOOST_PP_SEQ_ELEM( \
 642                     BOOST_PP_SUB(BOOST_PP_TUPLE_ELEM(4,2,split_args), n) \
 643                   , BOOST_PP_TUPLE_ELEM(4,3,split_args) \
 644                 ) \
 645               , tag_namespace \
 646             ) \
 647         ); \
 648     }
 649
 650 # define BOOST_PARAMETER_FUNCTION_DEFAULT_EVAL_ACTUAL_DEFAULT(arg) \
 651     BOOST_PARAMETER_FUNCTION_CAST( \
 652         boost::parameter::aux::as_lvalue(BOOST_PARAMETER_FN_ARG_DEFAULT(arg), 0L) \
 653       , BOOST_PARAMETER_FN_ARG_PRED(arg) \
 654       , Args \
 655     )
 656
 657 # define BOOST_PARAMETER_FUNCTION_DEFAULT_EVAL_DEFAULT_BODY(name, n, split_args, tag_ns, const_) \
 658     template < \
 659         class ResultType \
 660       , class Args \
 661         BOOST_PARAMETER_FUNCTION_DEFAULT_ARGUMENTS( \
 662             BOOST_PARAMETER_FUNCTION_DEFAULT_FUNCTION_TEMPLATE_ARG \
 663           , BOOST_PP_INC(n) \
 664           , split_args \
 665         ) \
 666     > \
 667     BOOST_PARAMETER_MEMBER_FUNCTION_STATIC(name) \
 668     ResultType BOOST_PARAMETER_FUNCTION_DEFAULT_NAME(name)( \
 669         ResultType(*)() \
 670       , Args const& args \
 671       , long \
 672         BOOST_PARAMETER_FUNCTION_DEFAULT_ARGUMENTS( \
 673             BOOST_PARAMETER_FUNCTION_DEFAULT_FUNCTION_ARG \
 674           , BOOST_PP_INC(n) \
 675           , split_args \
 676         ) \
 677       , boost::parameter::aux::use_default_tag \
 678     ) BOOST_PP_EXPR_IF(const_, const) \
 679     { \
 680         return BOOST_PARAMETER_FUNCTION_DEFAULT_NAME(name)( \
 681             (ResultType(*)())0 \
 682           , args \
 683           , 0L \
 684             BOOST_PARAMETER_FUNCTION_DEFAULT_ARGUMENTS( \
 685                 BOOST_PARAMETER_FUNCTION_DEFAULT_FUNCTION_PARAMETER \
 686               , BOOST_PP_INC(n) \
 687               , split_args \
 688             ) \
 689           , BOOST_PARAMETER_FUNCTION_DEFAULT_EVAL_ACTUAL_DEFAULT( \
 690                 BOOST_PP_SEQ_ELEM( \
 691                     BOOST_PP_SUB(BOOST_PP_TUPLE_ELEM(4,2,split_args), BOOST_PP_INC(n)) \
 692                   , BOOST_PP_TUPLE_ELEM(4,3,split_args) \
 693                 ) \
 694             ) \
 695         ); \
 696     }
 697
 698 // Produces a forwarding layer in the default evaluation machine.
 699 //
 700 // data is a tuple:
 701 //
 702 //   (name, split_args)
 703 //
 704 // Where name is the base name of the function, and split_args is a tuple:
 705 //
 706 //   (required_count, required_args, optional_count, required_args)
 707 //
 708
 709
 710 // defines the actual function body for BOOST_PARAMETER_FUNCTION_DEFAULT_FUNCTION below.
 711 # define BOOST_PARAMETER_FUNCTION_DEFAULT_FUNCTION0(z, n, data) \
 712     template < \
 713         class ResultType \
 714       , class Args \
 715         BOOST_PARAMETER_FUNCTION_DEFAULT_ARGUMENTS( \
 716             BOOST_PARAMETER_FUNCTION_DEFAULT_FUNCTION_TEMPLATE_ARG \
 717           , n \
 718           , BOOST_PP_TUPLE_ELEM(5,1,data) \
 719         ) \
 720     > \
 721     BOOST_PARAMETER_MEMBER_FUNCTION_STATIC(BOOST_PP_TUPLE_ELEM(5,0,data)) \
 722     ResultType BOOST_PARAMETER_FUNCTION_DEFAULT_NAME(BOOST_PP_TUPLE_ELEM(5,0,data))( \
 723         ResultType(*)() \
 724       , Args const& args \
 725       , int \
 726         BOOST_PARAMETER_FUNCTION_DEFAULT_ARGUMENTS( \
 727             BOOST_PARAMETER_FUNCTION_DEFAULT_FUNCTION_ARG \
 728           , n \
 729           , BOOST_PP_TUPLE_ELEM(5,1,data) \
 730         ) \
 731     ) BOOST_PP_EXPR_IF(BOOST_PP_TUPLE_ELEM(5,2,data), const) \
 732     BOOST_PP_IF( \
 733         n \
 734       , BOOST_PARAMETER_FUNCTION_DEFAULT_FUNCTION_BODY \
 735       , ; BOOST_PP_TUPLE_EAT(4) \
 736     )( \
 737         BOOST_PP_TUPLE_ELEM(5,0,data) \
 738       , n \
 739       , BOOST_PP_TUPLE_ELEM(5,1,data) \
 740       , BOOST_PP_TUPLE_ELEM(5,3,data) \
 741     )
 742
 743 # define BOOST_PARAMETER_FUNCTION_DEFAULT_FUNCTION(z, n, data) \
 744     BOOST_PP_IF( \
 745         BOOST_PP_AND( \
 746             BOOST_PP_NOT(n) \
 747           , BOOST_PP_TUPLE_ELEM(5,4,data) \
 748         ) \
 749       , BOOST_PP_TUPLE_EAT(3) \
 750       , BOOST_PARAMETER_FUNCTION_DEFAULT_FUNCTION0 \
 751     )(z, n, data) \
 752     BOOST_PP_IF( \
 753         BOOST_PP_EQUAL(n, BOOST_PP_TUPLE_ELEM(4,2,BOOST_PP_TUPLE_ELEM(5,1,data))) \
 754       , BOOST_PP_TUPLE_EAT(5) \
 755       , BOOST_PARAMETER_FUNCTION_DEFAULT_EVAL_DEFAULT_BODY \
 756     )( \
 757         BOOST_PP_TUPLE_ELEM(5,0,data) \
 758       , n \
 759       , BOOST_PP_TUPLE_ELEM(5,1,data) \
 760       , BOOST_PP_TUPLE_ELEM(5,3,data) \
 761       , BOOST_PP_TUPLE_ELEM(5,2,data) \
 762     )
 763
 764 # define BOOST_PARAMETER_FUNCTION_DEFAULT_GET_ARG(r, tag_ns, arg) \
 765     , BOOST_PARAMETER_FUNCTION_CAST( \
 766           args[ \
 767               boost::parameter::keyword<tag_ns::BOOST_PARAMETER_FN_ARG_KEYWORD(arg)>::instance \
 768           ] \
 769         , BOOST_PARAMETER_FN_ARG_PRED(arg) \
 770         , Args \
 771       )
 772
 773 // Generates the function template that recives a ArgumentPack, and then
 774 // goes on to call the layers of overloads generated by
 775 // BOOST_PARAMETER_FUNCTION_DEFAULT_LAYER.
 776 # define BOOST_PARAMETER_FUNCTION_INITIAL_DISPATCH_FUNCTION(name, split_args, const_, tag_ns) \
 777     template <class Args> \
 778     typename BOOST_PARAMETER_FUNCTION_RESULT_NAME(name)<Args>::type \
 779     BOOST_PARAMETER_MEMBER_FUNCTION_STATIC(name) \
 780     BOOST_PARAMETER_IMPL(name)(Args const& args) BOOST_PP_EXPR_IF(const_, const) \
 781     { \
 782         return BOOST_PARAMETER_FUNCTION_DEFAULT_NAME(name)( \
 783             (typename BOOST_PARAMETER_FUNCTION_RESULT_NAME(name)<Args>::type(*)())0 \
 784           , args \
 785           , 0L \
 786  \
 787             BOOST_PP_SEQ_FOR_EACH( \
 788                 BOOST_PARAMETER_FUNCTION_DEFAULT_GET_ARG \
 789               , tag_ns \
 790               , BOOST_PP_TUPLE_ELEM(4,1,split_args) \
 791             ) \
 792  \
 793         ); \
 794     }
 795
 796 // Helper for BOOST_PARAMETER_FUNCTION_DEFAULT_LAYER below.
 797 # define BOOST_PARAMETER_FUNCTION_DEFAULT_LAYER_AUX( \
 798     name, split_args, skip_fwd_decl, const_, tag_namespace \
 799   ) \
 800     BOOST_PP_REPEAT_FROM_TO( \
 801         0 \
 802       , BOOST_PP_INC(BOOST_PP_TUPLE_ELEM(4, 2, split_args)) \
 803       , BOOST_PARAMETER_FUNCTION_DEFAULT_FUNCTION \
 804       , (name, split_args, const_, tag_namespace, skip_fwd_decl) \
 805     ) \
 806  \
 807     BOOST_PARAMETER_FUNCTION_INITIAL_DISPATCH_FUNCTION(name, split_args, const_, tag_namespace) \
 808 \
 809     template < \
 810         class ResultType \
 811       , class Args \
 812         BOOST_PARAMETER_FUNCTION_DEFAULT_ARGUMENTS( \
 813             BOOST_PARAMETER_FUNCTION_DEFAULT_FUNCTION_TEMPLATE_ARG \
 814           , 0 \
 815           , split_args \
 816         ) \
 817     > \
 818     BOOST_PARAMETER_MEMBER_FUNCTION_STATIC(name) \
 819     ResultType BOOST_PARAMETER_FUNCTION_DEFAULT_NAME(name)( \
 820         ResultType(*)() \
 821       , Args const& \
 822       , int \
 823         BOOST_PARAMETER_FUNCTION_DEFAULT_ARGUMENTS( \
 824             BOOST_PARAMETER_FUNCTION_DEFAULT_FUNCTION_ARG \
 825           , 0 \
 826           , split_args \
 827         ) \
 828     ) BOOST_PP_EXPR_IF(const_, const)
 829
 830 // Generates a bunch of forwarding functions that each extract
 831 // one more argument.
 832 # define BOOST_PARAMETER_FUNCTION_DEFAULT_LAYER(name, args, skip_fwd_decl, const_, tag_ns) \
 833     BOOST_PARAMETER_FUNCTION_DEFAULT_LAYER_AUX( \
 834         name, BOOST_PARAMETER_FUNCTION_SPLIT_ARGS(args), skip_fwd_decl, const_, tag_ns \
 835     )
 836 /**/
 837
 838 // Defines the result metafunction and the parameters specialization.
 839 # define BOOST_PARAMETER_FUNCTION_HEAD(result, name, tag_namespace, args)   \
 840       BOOST_PARAMETER_FUNCTION_RESULT_(result, name, args)                   \
 841                                                                             \
 842           BOOST_PARAMETER_FUNCTION_PARAMETERS(tag_namespace, name, args)    \
 843           BOOST_PARAMETER_FUNCTION_PARAMETERS_NAME(name);                   \
 844
 845 // Helper for BOOST_PARAMETER_FUNCTION below.
 846 # define BOOST_PARAMETER_FUNCTION_AUX(result, name, tag_namespace, args)    \
 847     BOOST_PARAMETER_FUNCTION_HEAD(result, name, tag_namespace, args)         \
 848     BOOST_PARAMETER_FUNCTION_IMPL_HEAD(name); \
 849 \
 850     BOOST_PARAMETER_FUNCTION_FWD_FUNCTIONS(                                  \
 851         result, name, args, 0                                                \
 852       , BOOST_PARAMETER_FUNCTION_FWD_COMBINATIONS(args)                      \
 853     )                                                                        \
 854                                                                              \
 855     BOOST_PARAMETER_FUNCTION_DEFAULT_LAYER(name, args, 0, 0, tag_namespace)
 856
 857 // Defines a Boost.Parameter enabled function with the new syntax.
 858 # define BOOST_PARAMETER_FUNCTION(result, name, tag_namespace, args)    \
 859     BOOST_PARAMETER_FUNCTION_AUX(                                       \
 860         result, name, tag_namespace                                      \
 861       , BOOST_PARAMETER_FLATTEN(3, 2, 3, args)                           \
 862     )                                                                    \
 863 /**/
 864
 865 // Defines a Boost.Parameter enabled function.
 866 # define BOOST_PARAMETER_BASIC_FUNCTION_AUX(result, name, tag_namespace, args)    \
 867     BOOST_PARAMETER_FUNCTION_HEAD(result, name, tag_namespace, args)        \
 868                                                                             \
 869     BOOST_PARAMETER_FUNCTION_IMPL_FWD(name)                                 \
 870                                                                             \
 871     BOOST_PARAMETER_FUNCTION_FWD_FUNCTIONS(                                 \
 872         result, name, args, 0                                               \
 873       , BOOST_PARAMETER_FUNCTION_FWD_COMBINATIONS(args)                     \
 874     )                                                                       \
 875                                                                             \
 876     BOOST_PARAMETER_FUNCTION_IMPL_HEAD(name)
 877
 878 # define BOOST_PARAMETER_BASIC_FUNCTION(result, name, tag_namespace, args)  \
 879     BOOST_PARAMETER_BASIC_FUNCTION_AUX(                                     \
 880         result, name, tag_namespace                                     \
 881       , BOOST_PARAMETER_FLATTEN(2, 2, 3, args)                          \
 882     )                                                                   \
 883 /**/
 884
 885 // Defines a Boost.Parameter enabled member function.
 886 # define BOOST_PARAMETER_BASIC_MEMBER_FUNCTION_AUX(result, name, tag_namespace, args, const_) \
 887     BOOST_PARAMETER_FUNCTION_HEAD(result, name, tag_namespace, args)                    \
 888                                                                                         \
 889     BOOST_PARAMETER_FUNCTION_FWD_FUNCTIONS(                                             \
 890         result, name, args, const_                                                      \
 891       , BOOST_PARAMETER_FUNCTION_FWD_COMBINATIONS(args)                                 \
 892     )                                                                                   \
 893                                                                                         \
 894     BOOST_PARAMETER_FUNCTION_IMPL_HEAD(name) BOOST_PP_EXPR_IF(const_, const)            \
 895 /**/
 896
 897 # define BOOST_PARAMETER_BASIC_MEMBER_FUNCTION(result, name, tag_namespace, args) \
 898     BOOST_PARAMETER_BASIC_MEMBER_FUNCTION_AUX( \
 899         result, name, tag_namespace \
 900       , BOOST_PARAMETER_FLATTEN(2, 2, 3, args) \
 901       , 0 \
 902     )
 903 /**/
 904
 905 # define BOOST_PARAMETER_BASIC_CONST_MEMBER_FUNCTION(result, name, tag_namespace, args) \
 906     BOOST_PARAMETER_BASIC_MEMBER_FUNCTION_AUX( \
 907         result, name, tag_namespace \
 908       , BOOST_PARAMETER_FLATTEN(2, 2, 3, args) \
 909       , 1 \
 910     )
 911 /**/
 912
 913
 914
 915 # define BOOST_PARAMETER_MEMBER_FUNCTION_AUX(result, name, tag_namespace, const_, args)    \
 916     BOOST_PARAMETER_FUNCTION_HEAD(result, name, tag_namespace, args)         \
 917 \
 918     BOOST_PARAMETER_FUNCTION_FWD_FUNCTIONS(                                  \
 919         result, name, args, const_                                           \
 920       , BOOST_PARAMETER_FUNCTION_FWD_COMBINATIONS(args)                      \
 921     )                                                                        \
 922                                                                              \
 923     BOOST_PARAMETER_FUNCTION_DEFAULT_LAYER(name, args, 1, const_, tag_namespace)
 924
 925 // Defines a Boost.Parameter enabled function with the new syntax.
 926 # define BOOST_PARAMETER_MEMBER_FUNCTION(result, name, tag_namespace, args)    \
 927     BOOST_PARAMETER_MEMBER_FUNCTION_AUX(                                       \
 928         result, name, tag_namespace, 0                                     \
 929       , BOOST_PARAMETER_FLATTEN(3, 2, 3, args)                           \
 930     )                                                                    \
 931 /**/
 932
 933 # define BOOST_PARAMETER_CONST_MEMBER_FUNCTION(result, name, tag_namespace, args)    \
 934     BOOST_PARAMETER_MEMBER_FUNCTION_AUX(                                       \
 935         result, name, tag_namespace, 1                                     \
 936       , BOOST_PARAMETER_FLATTEN(3, 2, 3, args)                           \
 937     )                                                                    \
 938 /**/
 939
 940 // Defines a Boost.Parameter enabled constructor.
 941
 942 # define BOOST_PARAMETER_FUNCTION_ARGUMENT(r, _, i, elem) \
 943     BOOST_PP_COMMA_IF(i) elem& BOOST_PP_CAT(a, i)
 944 /**/
 945
 946 # define BOOST_PARAMETER_FUNCTION_FWD_CONSTRUCTOR00(z, n, r, data, elem) \
 947     BOOST_PP_IF( \
 948         n \
 949       , BOOST_PARAMETER_FUNCTION_FWD_FUNCTION_TEMPLATE_Z, BOOST_PP_TUPLE_EAT(2) \
 950     )(z, n) \
 951     BOOST_PP_EXPR_IF(BOOST_PP_EQUAL(n,1), explicit) \
 952     BOOST_PP_TUPLE_ELEM(6,2,data)( \
 953         BOOST_PP_IF( \
 954             n \
 955           , BOOST_PP_SEQ_FOR_EACH_I_R \
 956           , BOOST_PP_TUPLE_EAT(4) \
 957         )( \
 958             r \
 959           , BOOST_PARAMETER_FUNCTION_ARGUMENT \
 960           , ~ \
 961           , elem \
 962         ) \
 963         BOOST_PP_IF(n, BOOST_PARAMETER_FUNCTION_FWD_MATCH_Z, BOOST_PP_TUPLE_EAT(4))( \
 964             z \
 965           , BOOST_PP_TUPLE_ELEM(6,3,data) \
 966           , BOOST_PP_CAT(constructor_parameters, __LINE__) \
 967           , n \
 968         ) \
 969     ) \
 970       : BOOST_PARAMETER_PARENTHESIZED_TYPE(BOOST_PP_TUPLE_ELEM(6,3,data)) ( \
 971             BOOST_PP_CAT(constructor_parameters, __LINE__)()( \
 972                 BOOST_PP_ENUM_PARAMS_Z(z, n, a) \
 973             ) \
 974         ) \
 975     {}
 976 /**/
 977
 978 # define BOOST_PARAMETER_FUNCTION_FWD_CONSTRUCTOR0(r, data, elem) \
 979     BOOST_PARAMETER_FUNCTION_FWD_CONSTRUCTOR00( \
 980         BOOST_PP_TUPLE_ELEM(6,0,data) \
 981       , BOOST_PP_TUPLE_ELEM(6,1,data) \
 982       , r \
 983       , data \
 984       , elem \
 985     )
 986 /**/
 987
 988 # define BOOST_PARAMETER_FUNCTION_FWD_PRODUCT(r, product) \
 989     (product)
 990 /**/
 991
 992 # define BOOST_PARAMETER_FUNCTION_FWD_CONSTRUCTOR_ARITY_0(z, n, data) \
 993     BOOST_PARAMETER_FUNCTION_FWD_CONSTRUCTOR00( \
 994         z, n, BOOST_PP_DEDUCE_R() \
 995       , (z, n, BOOST_PP_TUPLE_REM(4) data) \
 996       , ~ \
 997     )
 998 /**/
 999
1000 # define BOOST_PARAMETER_FUNCTION_FWD_CONSTRUCTOR_ARITY_N(z, n, data) \
1001     BOOST_PP_SEQ_FOR_EACH( \
1002         BOOST_PARAMETER_FUNCTION_FWD_CONSTRUCTOR0 \
1003       , (z, n, BOOST_PP_TUPLE_REM(4) data) \
1004       , BOOST_PP_SEQ_FOR_EACH_PRODUCT( \
1005             BOOST_PARAMETER_FUNCTION_FWD_PRODUCT \
1006           , BOOST_PP_SEQ_FIRST_N( \
1007                 n, BOOST_PP_TUPLE_ELEM(4,2,data) \
1008             ) \
1009         ) \
1010     )
1011 /**/
1012
1013 # define BOOST_PARAMETER_FUNCTION_FWD_CONSTRUCTOR(z, n, data) \
1014     BOOST_PP_IF( \
1015         n \
1016       , BOOST_PARAMETER_FUNCTION_FWD_CONSTRUCTOR_ARITY_N \
1017       , BOOST_PARAMETER_FUNCTION_FWD_CONSTRUCTOR_ARITY_0 \
1018     )(z,n,data) \
1019 /**/
1020
1021 # define BOOST_PARAMETER_FUNCTION_FWD_CONSTRUCTORS0(class_,base,args,combinations,range) \
1022     BOOST_PP_REPEAT_FROM_TO( \
1023         BOOST_PP_TUPLE_ELEM(2,0,range), BOOST_PP_TUPLE_ELEM(2,1,range) \
1024       , BOOST_PARAMETER_FUNCTION_FWD_CONSTRUCTOR \
1025       , (class_,base,combinations,BOOST_PP_TUPLE_ELEM(2,1,range)) \
1026     )
1027 /**/
1028
1029 # define BOOST_PARAMETER_FUNCTION_FWD_CONSTRUCTORS(class_,base,args,combinations) \
1030     BOOST_PARAMETER_FUNCTION_FWD_CONSTRUCTORS0( \
1031         class_, base, args, combinations, BOOST_PARAMETER_ARITY_RANGE(args) \
1032     )
1033 /**/
1034
1035 # define BOOST_PARAMETER_CONSTRUCTOR_AUX(class_, base, tag_namespace, args) \
1036     BOOST_PARAMETER_FUNCTION_PARAMETERS(tag_namespace, ctor, args)          \
1037         BOOST_PP_CAT(constructor_parameters, __LINE__); \
1038 \
1039     BOOST_PARAMETER_FUNCTION_FWD_CONSTRUCTORS( \
1040         class_, base, args \
1041       , BOOST_PARAMETER_FUNCTION_FWD_COMBINATIONS(args) \
1042     ) \
1043 /**/
1044
1045 # define BOOST_PARAMETER_CONSTRUCTOR(class_, base, tag_namespace, args) \
1046     BOOST_PARAMETER_CONSTRUCTOR_AUX( \
1047         class_, base, tag_namespace \
1048       , BOOST_PARAMETER_FLATTEN(2, 2, 3, args) \
1049     )
1050 /**/
1051
1052 # ifndef BOOST_NO_FUNCTION_TEMPLATE_ORDERING
1053 #  define BOOST_PARAMETER_FUNCTION_FWD_COMBINATION(r, _, i, elem) \
1054     (BOOST_PP_IF( \
1055         BOOST_PARAMETER_FUNCTION_IS_KEYWORD_QUALIFIER( \
1056             BOOST_PARAMETER_FN_ARG_NAME(elem) \
1057         ) \
1058       , (const ParameterArgumentType ## i)(ParameterArgumentType ## i) \
1059       , (const ParameterArgumentType ## i) \
1060     ))
1061 // No partial ordering. This feature doesn't work.
1062 # else
1063 #  define BOOST_PARAMETER_FUNCTION_FWD_COMBINATION(r, _, i, elem) \
1064     (BOOST_PP_IF( \
1065         BOOST_PARAMETER_FUNCTION_IS_KEYWORD_QUALIFIER( \
1066             BOOST_PARAMETER_FN_ARG_NAME(elem) \
1067         ) \
1068       , (ParameterArgumentType ## i) \
1069       , (const ParameterArgumentType ## i) \
1070     ))
1071 # endif
1072
1073 # define BOOST_PARAMETER_FUNCTION_FWD_COMBINATIONS(args) \
1074     BOOST_PP_SEQ_FOR_EACH_I(BOOST_PARAMETER_FUNCTION_FWD_COMBINATION, ~, args)
1075
1076 #endif // BOOST_PARAMETER_PREPROCESSOR_060206_HPP
1077