1 
2 #ifndef BOOST_MPL_NEGATE_HPP_INCLUDED
3 #define BOOST_MPL_NEGATE_HPP_INCLUDED
4 
5 // Copyright Aleksey Gurtovoy 2000-2004
6 //
7 // Distributed under the Boost Software License, Version 1.0.
8 // (See accompanying file LICENSE_1_0.txt or copy at
9 // http://www.boost.org/LICENSE_1_0.txt)
10 //
11 // See http://www.boost.org/libs/mpl for documentation.
12 
13 // $Id: negate.hpp 49267 2008-10-11 06:19:02Z agurtovoy $
14 // $Date: 2008-10-10 23:19:02 -0700 (Fri, 10 Oct 2008) $
15 // $Revision: 49267 $
16 
17 #include <boost/mpl/integral_c.hpp>
18 #include <boost/mpl/aux_/msvc_eti_base.hpp>
19 #include <boost/mpl/aux_/na_spec.hpp>
20 #include <boost/mpl/aux_/lambda_support.hpp>
21 #include <boost/mpl/aux_/config/eti.hpp>
22 #include <boost/mpl/aux_/config/integral.hpp>
23 #include <boost/mpl/aux_/config/static_constant.hpp>
24 
25 namespace boost { namespace mpl {
26 
27 template< typename Tag > struct negate_impl;
28 
29 template< typename T > struct negate_tag
30 {
31     typedef typename T::tag type;
32 };
33 
34 template<
35       typename BOOST_MPL_AUX_NA_PARAM(N)
36     >
37 struct negate
38 #if !defined(BOOST_MPL_CFG_MSVC_ETI_BUG)
39     : negate_impl<
40           typename negate_tag<N>::type
41         >::template apply<N>::type
42 #else
43     : aux::msvc_eti_base< typename apply_wrap1<
44           negate_impl< typename negate_tag<N>::type >
45         , N
46         >::type >::type
47 #endif
48 {
49     BOOST_MPL_AUX_LAMBDA_SUPPORT(1, negate, (N))
50 };
51 
52 BOOST_MPL_AUX_NA_SPEC(1, negate)
53 
54 
55 #if defined(BOOST_MPL_CFG_NO_NESTED_VALUE_ARITHMETIC)
56 namespace aux {
57 template< typename T, T n > struct negate_wknd
58 {
59     BOOST_STATIC_CONSTANT(T, value = -n);
60     typedef integral_c<T,value> type;
61 };
62 }
63 #endif
64 
65 template<>
66 struct negate_impl<integral_c_tag>
67 {
68 #if defined(BOOST_MPL_CFG_NO_NESTED_VALUE_ARITHMETIC)
69     template< typename N > struct apply
70         : aux::negate_wknd< typename N::value_type, N::value >
71 #else
72     template< typename N > struct apply
73         : integral_c< typename N::value_type, (-N::value) >
74 #endif
75     {
76     };
77 };
78 
79 }}
80 
81 #endif // BOOST_MPL_NEGATE_HPP_INCLUDED
82