ceph/src/boost/libs/algorithm/include/boost/algorithm/cxx11/one_of.hpp

   1 /*
   2    Copyright (c) Marshall Clow 2008-2012.
   3
   4    Distributed under the Boost Software License, Version 1.0. (See accompanying
   5    file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6 */
   7
   8 /// \file one_of.hpp
   9 /// \brief Test ranges to see if only one element matches a value or predicate.
  10 /// \author Marshall Clow
  11
  12 #ifndef BOOST_ALGORITHM_ONE_OF_HPP
  13 #define BOOST_ALGORITHM_ONE_OF_HPP
  14
  15 #include <algorithm>            // for std::find and std::find_if
  16 #include <boost/algorithm/cxx11/none_of.hpp>
  17
  18 #include <boost/range/begin.hpp>
  19 #include <boost/range/end.hpp>
  20
  21 namespace boost { namespace algorithm {
  22
  23 /// \fn one_of ( InputIterator first, InputIterator last, Predicate p )
  24 /// \return true if the predicate 'p' is true for exactly one item in [first, last).
  25 ///
  26 /// \param first The start of the input sequence
  27 /// \param last  One past the end of the input sequence
  28 /// \param p     A predicate for testing the elements of the sequence
  29 ///
  30 template<typename InputIterator, typename Predicate>
  31 bool one_of ( InputIterator first, InputIterator last, Predicate p )
  32 {
  33     InputIterator i = std::find_if (first, last, p);
  34     if (i == last)
  35         return false;    // Didn't occur at all
  36     return boost::algorithm::none_of (++i, last, p);
  37 }
  38
  39 /// \fn one_of ( const Range &r, Predicate p )
  40 /// \return true if the predicate 'p' is true for exactly one item in the range.
  41 ///
  42 /// \param r    The input range
  43 /// \param p    A predicate for testing the elements of the range
  44 ///
  45 template<typename Range, typename Predicate>
  46 bool one_of ( const Range &r, Predicate p )
  47 {
  48     return boost::algorithm::one_of ( boost::begin (r), boost::end (r), p );
  49 }
  50
  51
  52 /// \fn one_of_equal ( InputIterator first, InputIterator last, const V &val )
  53 /// \return true if the value 'val' exists only once in [first, last).
  54 ///
  55 /// \param first    The start of the input sequence
  56 /// \param last     One past the end of the input sequence
  57 /// \param val      A value to compare against
  58 ///
  59 template<typename InputIterator, typename V>
  60 bool one_of_equal ( InputIterator first, InputIterator last, const V &val )
  61 {
  62     InputIterator i = std::find (first, last, val); // find first occurrence of 'val'
  63     if (i == last)
  64         return false;                    // Didn't occur at all
  65     return boost::algorithm::none_of_equal (++i, last, val);
  66 }
  67
  68 /// \fn one_of_equal ( const Range &r, const V &val )
  69 /// \return true if the value 'val' exists only once in the range.
  70 ///
  71 /// \param r    The input range
  72 /// \param val  A value to compare against
  73 ///
  74 template<typename Range, typename V>
  75 bool one_of_equal ( const Range &r, const V &val )
  76 {
  77     return boost::algorithm::one_of_equal ( boost::begin (r), boost::end (r), val );
  78 }
  79
  80 }} // namespace boost and algorithm
  81
  82 #endif // BOOST_ALGORITHM_ALL_HPP