ceph/src/boost/libs/mpl/doc/src/refmanual/plus.rst

   1 .. Metafunctions/Arithmetic Operations//plus |10
   2
   3 plus
   4 ====
   5
   6 Synopsis
   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 plus
  19     {
  20         typedef |unspecified| type;
  21     };
  22
  23
  24
  25 Description
  26 -----------
  27
  28 Returns the sum of its arguments.
  29
  30
  31 Header
  32 ------
  33
  34 .. parsed-literal::
  35
  36     #include <boost/mpl/plus.hpp>
  37     #include <boost/mpl/arithmetic.hpp>
  38
  39
  40 Model of
  41 --------
  42
  43 |Numeric Metafunction|
  44
  45
  46
  47 Parameters
  48 ----------
  49
  50 +---------------+---------------------------+-----------------------------------------------+
  51 | Parameter     | Requirement               | Description                                   |
  52 +===============+===========================+===============================================+
  53 | |T1...Tn|     | |Integral Constant|       | Operation's arguments.                        |
  54 +---------------+---------------------------+-----------------------------------------------+
  55
  56 |Note:| |numeric metafunction note| |-- end note|
  57
  58
  59 Expression semantics
  60 --------------------
  61
  62 For any |Integral Constant|\ s |c1...cn|:
  63
  64
  65 .. parsed-literal::
  66
  67     typedef plus<c1,\ |...|\ c\ *n*\>::type r;
  68
  69 :Return type:
  70     |Integral Constant|.
  71
  72 :Semantics:
  73     Equivalent to
  74
  75     .. parsed-literal::
  76
  77         typedef integral_c<
  78               typeof(c1::value + c2::value)
  79             , ( c1::value + c2::value )
  80             > c;
  81
  82         typedef plus<c,c3,\ |...|\c\ *n*\>::type r;
  83
  84 .. ..........................................................................
  85
  86 .. parsed-literal::
  87
  88     typedef plus<c1,\ |...|\ c\ *n*\> r;
  89
  90 :Return type:
  91     |Integral Constant|.
  92
  93 :Semantics:
  94     Equivalent to
  95
  96     .. parsed-literal::
  97
  98         struct r : plus<c1,\ |...|\ c\ *n*\>::type {};
  99
 100
 101
 102
 103 Complexity
 104 ----------
 105
 106 Amortized constant time.
 107
 108
 109 Example
 110 -------
 111
 112 .. parsed-literal::
 113
 114     typedef plus< int_<-10>, int_<3>, long_<1> >::type r;
 115     BOOST_MPL_ASSERT_RELATION( r::value, ==, -6 );
 116     BOOST_MPL_ASSERT(( is_same< r::value_type, long > ));
 117
 118
 119 See also
 120 --------
 121
 122 |Arithmetic Operations|, |Numeric Metafunction|, |numeric_cast|, |minus|, |negate|, |times|
 123
 124
 125 .. copyright:: Copyright ©  2001-2009 Aleksey Gurtovoy and David Abrahams
 126    Distributed under the Boost Software License, Version 1.0. (See accompanying
 127    file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)