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1.. Metafunctions/Arithmetic Operations//minus |20
2
3minus
4=====
5
6Synopsis
7--------
8
9.. parsed-literal::
10
11    template<
12          typename T1
13        , typename T2
14        , typename T3 = |unspecified|
15        |...|
16        , typename T\ *n* = |unspecified|
17        >
18    struct minus
19    {
20        typedef |unspecified| type;
21    };
22
23
24
25Description
26-----------
27
28Returns the difference of its arguments.
29
30
31Header
32------
33
34.. parsed-literal::
35
36    #include <boost/mpl/minus.hpp>
37    #include <boost/mpl/arithmetic.hpp>
38
39
40Model of
41--------
42
43|Numeric Metafunction|
44
45
46Parameters
47----------
48
49+---------------+---------------------------+-----------------------------------------------+
50| Parameter     | Requirement               | Description                                   |
51+===============+===========================+===============================================+
52| |T1...Tn|     | |Integral Constant|       | Operation's arguments.                        |
53+---------------+---------------------------+-----------------------------------------------+
54
55|Note:| |numeric metafunction note| |-- end note|
56
57
58Expression semantics
59--------------------
60
61For any |Integral Constant|\ s |c1...cn|:
62
63
64.. parsed-literal::
65
66    typedef minus<c1,\ |...|\ c\ *n*\>::type r;
67
68:Return type:
69    |Integral Constant|.
70
71:Semantics:
72    Equivalent to
73
74    .. parsed-literal::
75
76        typedef integral_c<
77              typeof(c1::value - c2::value)
78            , ( c1::value - c2::value )
79            > c;
80
81        typedef minus<c,c3,\ |...|\c\ *n*\>::type r;
82
83.. ..........................................................................
84
85.. parsed-literal::
86
87    typedef minus<c1,\ |...|\ c\ *n*\> r;
88
89:Return type:
90    |Integral Constant|.
91
92:Semantics:
93    Equivalent to
94
95    .. parsed-literal::
96
97        struct r : minus<c1,\ |...|\ c\ *n*\>::type {};
98
99
100Complexity
101----------
102
103Amortized constant time.
104
105
106Example
107-------
108
109.. parsed-literal::
110
111    typedef minus< int_<-10>, int_<3>, long_<1> >::type r;
112    BOOST_MPL_ASSERT_RELATION( r::value, ==, -14 );
113    BOOST_MPL_ASSERT(( is_same< r::value_type, long > ));
114
115
116See also
117--------
118
119|Arithmetic Operations|, |Numeric Metafunction|, |numeric_cast|, |plus|, |negate|, |times|
120
121
122.. copyright:: Copyright �  2001-2009 Aleksey Gurtovoy and David Abrahams
123   Distributed under the Boost Software License, Version 1.0. (See accompanying
124   file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
125