source: NonGTP/Boost/boost/mpl/aux_/template_arity.hpp @ 857

Revision 857, 4.9 KB checked in by igarcia, 19 years ago (diff)
Line 
1
2#if !defined(BOOST_PP_IS_ITERATING)
3
4///// header body
5
6#ifndef BOOST_MPL_AUX_TEMPLATE_ARITY_HPP_INCLUDED
7#define BOOST_MPL_AUX_TEMPLATE_ARITY_HPP_INCLUDED
8
9// Copyright Aleksey Gurtovoy 2001-2004
10//
11// Distributed under the Boost Software License, Version 1.0.
12// (See accompanying file LICENSE_1_0.txt or copy at
13// http://www.boost.org/LICENSE_1_0.txt)
14//
15// See http://www.boost.org/libs/mpl for documentation.
16
17// $Source: /cvsroot/boost/boost/boost/mpl/aux_/template_arity.hpp,v $
18// $Date: 2004/09/07 12:24:48 $
19// $Revision: 1.11 $
20
21#include <boost/mpl/aux_/config/ttp.hpp>
22#include <boost/mpl/aux_/config/lambda.hpp>
23
24#if !defined(BOOST_MPL_PREPROCESSING_MODE)
25#   include <boost/mpl/aux_/template_arity_fwd.hpp>
26#   include <boost/mpl/int.hpp>
27#   if !defined(BOOST_MPL_CFG_NO_FULL_LAMBDA_SUPPORT)
28#   if defined(BOOST_MPL_CFG_EXTENDED_TEMPLATE_PARAMETERS_MATCHING)
29#       include <boost/mpl/aux_/type_wrapper.hpp>
30#   endif
31#   else
32#       include <boost/mpl/aux_/has_rebind.hpp>
33#   endif
34#endif
35
36#include <boost/mpl/aux_/config/static_constant.hpp>
37#include <boost/mpl/aux_/config/use_preprocessed.hpp>
38
39#if !defined(BOOST_MPL_CFG_NO_PREPROCESSED_HEADERS) \
40    && !defined(BOOST_MPL_PREPROCESSING_MODE)
41
42#   define BOOST_MPL_PREPROCESSED_HEADER template_arity.hpp
43#   include <boost/mpl/aux_/include_preprocessed.hpp>
44
45#else
46
47#   if !defined(BOOST_MPL_CFG_NO_FULL_LAMBDA_SUPPORT)
48#   if defined(BOOST_MPL_CFG_EXTENDED_TEMPLATE_PARAMETERS_MATCHING)
49
50#   include <boost/mpl/limits/arity.hpp>
51#   include <boost/mpl/aux_/preprocessor/range.hpp>
52#   include <boost/mpl/aux_/preprocessor/repeat.hpp>
53#   include <boost/mpl/aux_/preprocessor/params.hpp>
54#   include <boost/mpl/aux_/nttp_decl.hpp>
55
56#   include <boost/preprocessor/seq/fold_left.hpp>
57#   include <boost/preprocessor/comma_if.hpp>
58#   include <boost/preprocessor/iterate.hpp>
59#   include <boost/preprocessor/inc.hpp>
60#   include <boost/preprocessor/cat.hpp>
61
62#   define AUX778076_ARITY BOOST_PP_INC(BOOST_MPL_LIMIT_METAFUNCTION_ARITY)
63
64namespace boost { namespace mpl { namespace aux {
65
66template< BOOST_MPL_AUX_NTTP_DECL(int, N) > struct arity_tag
67{
68    typedef char (&type)[N + 1];
69};
70
71#   define AUX778076_MAX_ARITY_OP(unused, state, i_) \
72    ( BOOST_PP_CAT(C,i_) > 0 ? BOOST_PP_CAT(C,i_) : state ) \
73/**/
74
75template<
76      BOOST_MPL_PP_PARAMS(AUX778076_ARITY, BOOST_MPL_AUX_NTTP_DECL(int, C))
77    >
78struct max_arity
79{
80    BOOST_STATIC_CONSTANT(int, value =
81          BOOST_PP_SEQ_FOLD_LEFT(
82              AUX778076_MAX_ARITY_OP
83            , -1
84            , BOOST_MPL_PP_RANGE(1, AUX778076_ARITY)
85            )
86        );
87};
88
89#   undef AUX778076_MAX_ARITY_OP
90
91arity_tag<0>::type arity_helper(...);
92
93#   define BOOST_PP_ITERATION_LIMITS (1, AUX778076_ARITY)
94#   define BOOST_PP_FILENAME_1 <boost/mpl/aux_/template_arity.hpp>
95#   include BOOST_PP_ITERATE()
96
97template< typename F, BOOST_MPL_AUX_NTTP_DECL(int, N) >
98struct template_arity_impl
99{
100    BOOST_STATIC_CONSTANT(int, value =
101          sizeof(arity_helper(type_wrapper<F>(),arity_tag<N>())) - 1
102        );
103};
104
105#   define AUX778076_TEMPLATE_ARITY_IMPL_INVOCATION(unused, i_, F) \
106    BOOST_PP_COMMA_IF(i_) template_arity_impl<F,BOOST_PP_INC(i_)>::value \
107/**/
108
109template< typename F >
110struct template_arity
111{
112    BOOST_STATIC_CONSTANT(int, value = (
113          max_arity< BOOST_MPL_PP_REPEAT(
114              AUX778076_ARITY
115            , AUX778076_TEMPLATE_ARITY_IMPL_INVOCATION
116            , F
117            ) >::value
118        ));
119       
120    typedef mpl::int_<value> type;
121};
122
123#   undef AUX778076_TEMPLATE_ARITY_IMPL_INVOCATION
124
125#   undef AUX778076_ARITY
126
127}}}
128
129#   endif // BOOST_MPL_CFG_EXTENDED_TEMPLATE_PARAMETERS_MATCHING
130#   else // BOOST_MPL_CFG_NO_FULL_LAMBDA_SUPPORT
131
132#   include <boost/mpl/aux_/config/eti.hpp>
133
134namespace boost { namespace mpl { namespace aux {
135
136template< bool >
137struct template_arity_impl
138{
139    template< typename F > struct result_
140        : mpl::int_<-1>
141    {
142    };
143};
144
145template<>
146struct template_arity_impl<true>
147{
148    template< typename F > struct result_
149        : F::arity
150    {
151    };
152};
153
154template< typename F >
155struct template_arity
156    : template_arity_impl< ::boost::mpl::aux::has_rebind<F>::value >
157        ::template result_<F>
158{
159};
160
161#if defined(BOOST_MPL_CFG_MSVC_ETI_BUG)
162template<>
163struct template_arity<int>
164    : mpl::int_<-1>
165{
166};
167#endif
168
169}}}
170
171#   endif // BOOST_MPL_CFG_NO_FULL_LAMBDA_SUPPORT
172
173#endif // BOOST_MPL_CFG_NO_PREPROCESSED_HEADERS
174#endif // BOOST_MPL_AUX_TEMPLATE_ARITY_HPP_INCLUDED
175
176///// iteration
177
178#else
179#define i_ BOOST_PP_FRAME_ITERATION(1)
180
181template<
182      template< BOOST_MPL_PP_PARAMS(i_, typename P) > class F
183    , BOOST_MPL_PP_PARAMS(i_, typename T)
184    >
185typename arity_tag<i_>::type
186arity_helper(type_wrapper< F<BOOST_MPL_PP_PARAMS(i_, T)> >, arity_tag<i_>);
187
188#undef i_
189#endif // BOOST_PP_IS_ITERATING
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