ceph/src/boost/libs/range/doc/reference/algorithm/count.qbk

   1 [/
   2     Copyright 2010 Neil Groves
   3     Distributed under the Boost Software License, Version 1.0.
   4     (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   5 /]
   6 [section:count count]
   7
   8 [heading Prototype]
   9
  10 ``
  11 template<class SinglePassRange, class Value>
  12 typename range_difference<SinglePassRange>::type
  13 count(SinglePassRange& rng, const Value& val);
  14
  15 template<class SinglePassRange, class Value>
  16 typename range_difference<const SinglePassRange>::type
  17 count(const SinglePassRange& rng, const Value& val);
  18 ``
  19
  20 [heading Description]
  21
  22 `count` returns the number of elements `x` in `rng` where `x == val` is `true`.
  23
  24 [heading Definition]
  25
  26 Defined in the header file `boost/range/algorithm/count.hpp`
  27
  28 [heading Requirements]
  29
  30 * `SinglePassRange` is a model of the __single_pass_range__ Concept.
  31 * `Value` is a model of the `EqualityComparableConcept`.
  32 * `SinglePassRange`'s value type is a model of the `EqualityComparableConcept`.
  33 * An object of `SinglePassRange`'s value type can be compared for equality with an object of type `Value`.
  34
  35 [heading Complexity]
  36
  37 Linear. Exactly `distance(rng)` comparisons.
  38
  39 [endsect]
  40
  41