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

   1 .. Iterators/Iterator Metafunctions//next |30
   2
   3 next
   4 ====
   5
   6 Synopsis
   7 --------
   8
   9 .. parsed-literal::
  10
  11     template<
  12           typename Iterator
  13         >
  14     struct next
  15     {
  16         typedef |unspecified| type;
  17     };
  18
  19
  20
  21 Description
  22 -----------
  23
  24 Returns the next iterator in the sequence. |Note:| ``next`` has a number of
  25 overloaded meanings, depending on the type of its argument. For instance,
  26 if ``X`` is an |Integral Constant|, ``next<X>`` returns an incremented
  27 |Integral Constant| of the same type. The following specification is
  28 iterator-specific. Please refer to the corresponding concept's
  29 documentation for the details of the alternative semantics |-- end note|.
  30
  31
  32 Header
  33 ------
  34
  35 .. parsed-literal::
  36
  37     #include <boost/mpl/next_prior.hpp>
  38
  39
  40 Parameters
  41 ----------
  42
  43 +---------------+---------------------------+-----------------------------------+
  44 | Parameter     | Requirement               | Description                       |
  45 +===============+===========================+===================================+
  46 | ``Iterator``  | |Forward Iterator|.       | An iterator to increment.         |
  47 +---------------+---------------------------+-----------------------------------+
  48
  49
  50 Expression semantics
  51 --------------------
  52
  53 For any |Forward Iterator|\ s ``iter``:
  54
  55
  56 .. parsed-literal::
  57
  58     typedef next<iter>::type j;
  59
  60 :Return type:
  61     |Forward Iterator|.
  62
  63 :Precondition:
  64     ``iter`` is incrementable.
  65
  66 :Semantics:
  67     ``j`` is an iterator pointing to the next element in the sequence, or
  68     is past-the-end. If ``iter`` is a user-defined iterator, the
  69     library-provided default implementation is equivalent to
  70
  71     .. parsed-literal::
  72
  73         typedef iter::next j;
  74
  75
  76 Complexity
  77 ----------
  78
  79 Amortized constant time.
  80
  81
  82 Example
  83 -------
  84
  85 .. parsed-literal::
  86
  87     typedef vector_c<int,1> v;
  88     typedef begin<v>::type first;
  89     typedef end<v>::type last;
  90
  91     BOOST_MPL_ASSERT(( is_same< next<first>::type, last > ));
  92
  93
  94 See also
  95 --------
  96
  97 |Iterators|, |begin| / |end|, |prior|, |deref|
  98
  99
 100 .. copyright:: Copyright ©  2001-2009 Aleksey Gurtovoy and David Abrahams
 101    Distributed under the Boost Software License, Version 1.0. (See accompanying
 102    file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)