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/*
Copyright (c) Marshall Clow 2008-2012.
Distributed under the Boost Software License, Version 1.0. (See accompanying
file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
*/
/// \file one_of.hpp
/// \brief Test ranges to see if only one element matches a value or predicate.
/// \author Marshall Clow
#ifndef BOOST_ALGORITHM_ONE_OF_HPP
#define BOOST_ALGORITHM_ONE_OF_HPP
#include <algorithm> // for std::find and std::find_if
#include <boost/algorithm/cxx11/none_of.hpp>
#include <boost/range/begin.hpp>
#include <boost/range/end.hpp>
namespace boost { namespace algorithm {
/// \fn one_of ( InputIterator first, InputIterator last, Predicate p )
/// \return true if the predicate 'p' is true for exactly one item in [first, last).
///
/// \param first The start of the input sequence
/// \param last One past the end of the input sequence
/// \param p A predicate for testing the elements of the sequence
///
template<typename InputIterator, typename Predicate>
bool one_of ( InputIterator first, InputIterator last, Predicate p )
{
InputIterator i = std::find_if (first, last, p);
if (i == last)
return false; // Didn't occur at all
return boost::algorithm::none_of (++i, last, p);
}
/// \fn one_of ( const Range &r, Predicate p )
/// \return true if the predicate 'p' is true for exactly one item in the range.
///
/// \param r The input range
/// \param p A predicate for testing the elements of the range
///
template<typename Range, typename Predicate>
bool one_of ( const Range &r, Predicate p )
{
return boost::algorithm::one_of ( boost::begin (r), boost::end (r), p );
}
/// \fn one_of_equal ( InputIterator first, InputIterator last, const V &val )
/// \return true if the value 'val' exists only once in [first, last).
///
/// \param first The start of the input sequence
/// \param last One past the end of the input sequence
/// \param val A value to compare against
///
template<typename InputIterator, typename V>
bool one_of_equal ( InputIterator first, InputIterator last, const V &val )
{
InputIterator i = std::find (first, last, val); // find first occurrence of 'val'
if (i == last)
return false; // Didn't occur at all
return boost::algorithm::none_of_equal (++i, last, val);
}
/// \fn one_of_equal ( const Range &r, const V &val )
/// \return true if the value 'val' exists only once in the range.
///
/// \param r The input range
/// \param val A value to compare against
///
template<typename Range, typename V>
bool one_of_equal ( const Range &r, const V &val )
{
return boost::algorithm::one_of_equal ( boost::begin (r), boost::end (r), val );
}
}} // namespace boost and algorithm
#endif // BOOST_ALGORITHM_ALL_HPP
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