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

   1 .. Algorithms/Querying Algorithms//equal |100
   2
   3 equal
   4 =====
   5
   6 Synopsis
   7 --------
   8
   9 .. parsed-literal::
  10
  11     template<
  12           typename Seq1
  13         , typename Seq2
  14         , typename Pred = is_same<_1,_2>
  15         >
  16     struct equal
  17     {
  18         typedef |unspecified| type;
  19     };
  20
  21
  22
  23 Description
  24 -----------
  25
  26 Returns a true-valued |Integral Constant| if the two sequences ``Seq1``
  27 and ``Seq2`` are identical when compared element-by-element.
  28
  29
  30 Header
  31 ------
  32
  33 .. parsed-literal::
  34
  35     #include <boost/mpl/equal.hpp>
  36
  37
  38
  39 Parameters
  40 ----------
  41
  42 +-------------------+-------------------------------+-----------------------------------+
  43 | Parameter         | Requirement                   | Description                       |
  44 +===================+===============================+===================================+
  45 | ``Seq1``, ``Seq2``| |Forward Sequence|            | Sequences to compare.             |
  46 +-------------------+-------------------------------+-----------------------------------+
  47 | ``Pred``          | Binary |Lambda Expression|    | A comparison criterion.           |
  48 +-------------------+-------------------------------+-----------------------------------+
  49
  50
  51 Expression semantics
  52 --------------------
  53
  54 For any |Forward Sequence|\ s ``s1`` and ``s2`` and a binary |Lambda Expression| ``pred``:
  55
  56
  57 .. parsed-literal::
  58
  59     typedef equal<s1,s2,pred>::type c;
  60
  61 :Return type:
  62     |Integral Constant|
  63
  64 :Semantics:
  65     ``c::value == true`` is and only if ``size<s1>::value == size<s2>::value``
  66     and for every iterator ``i`` in |begin/end<s1>| ``deref<i>::type`` is identical to
  67
  68     .. parsed-literal::
  69
  70         advance< begin<s2>::type, distance< begin<s1>::type,i >::type >::type
  71
  72
  73 Complexity
  74 ----------
  75
  76 Linear. At most ``size<s1>::value`` comparisons.
  77
  78
  79 Example
  80 -------
  81
  82 .. parsed-literal::
  83
  84     typedef vector<char,int,unsigned,long,unsigned long> s1;
  85     typedef list<char,int,unsigned,long,unsigned long> s2;
  86
  87     BOOST_MPL_ASSERT(( equal<s1,s2> ));
  88
  89
  90 See also
  91 --------
  92
  93 |Querying Algorithms|, |find|, |find_if|
  94
  95
  96 .. copyright:: Copyright ©  2001-2009 Aleksey Gurtovoy and David Abrahams
  97    Distributed under the Boost Software License, Version 1.0. (See accompanying
  98    file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)