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

   1 .. Sequences/Intrinsic Metafunctions//end
   2
   3 end
   4 ===
   5
   6 Synopsis
   7 --------
   8
   9 .. parsed-literal::
  10
  11     template<
  12           typename X
  13         >
  14     struct end
  15     {
  16         typedef |unspecified| type;
  17     };
  18
  19
  20
  21 Description
  22 -----------
  23
  24 Returns the sequence's past-the-end iterator. If the argument is not a
  25 |Forward Sequence|, returns |void_|.
  26
  27
  28 Header
  29 ------
  30
  31 .. parsed-literal::
  32
  33     #include <boost/mpl/begin_end.hpp>
  34
  35
  36 Model of
  37 --------
  38
  39 |Tag Dispatched Metafunction|
  40
  41
  42 Parameters
  43 ----------
  44
  45 +---------------+-------------------+-----------------------------------------------+
  46 | Parameter     | Requirement       | Description                                   |
  47 +===============+===================+===============================================+
  48 | ``X``         | Any type          | A type whose end iterator, if any, will be    |
  49 |               |                   | returned.                                     |
  50 +---------------+-------------------+-----------------------------------------------+
  51
  52
  53 Expression semantics
  54 --------------------
  55
  56 For any arbitrary type ``x``:
  57
  58 .. parsed-literal::
  59
  60     typedef end<x>::type last;
  61
  62 :Return type:
  63     |Forward Iterator| or |void_|.
  64
  65 :Semantics:
  66     If ``x`` is |Forward Sequence|, ``last`` is an iterator pointing one past the
  67     last element in ``s``; otherwise ``last`` is |void_|.
  68
  69 :Postcondition:
  70     If ``last`` is an iterator, it is past-the-end.
  71
  72
  73 Complexity
  74 ----------
  75
  76 Amortized constant time.
  77
  78
  79 Example
  80 -------
  81
  82 .. parsed-literal::
  83
  84     typedef vector<long> v;
  85     typedef begin<v>::type first;
  86     typedef end<v>::type last;
  87
  88     BOOST_MPL_ASSERT(( is_same< next<first>::type, last > ));
  89
  90
  91 See also
  92 --------
  93
  94 |Iterators|, |Forward Sequence|, |begin|, |end|, |next|
  95
  96
  97 .. copyright:: Copyright ©  2001-2009 Aleksey Gurtovoy and David Abrahams
  98    Distributed under the Boost Software License, Version 1.0. (See accompanying
  99    file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)