Chris@16: /* 
Chris@16:    Copyright (c) Marshall Clow 2008-2012.
Chris@16: 
Chris@16:    Distributed under the Boost Software License, Version 1.0. (See accompanying
Chris@16:    file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@16: */
Chris@16: 
Chris@16: /// \file one_of.hpp
Chris@16: /// \brief Test ranges to see if only one element matches a value or predicate.
Chris@16: /// \author Marshall Clow
Chris@16: 
Chris@16: #ifndef BOOST_ALGORITHM_ONE_OF_HPP
Chris@16: #define BOOST_ALGORITHM_ONE_OF_HPP
Chris@16: 
Chris@16: #include <algorithm>            // for std::find and std::find_if
Chris@16: #include <boost/algorithm/cxx11/none_of.hpp>
Chris@16: 
Chris@16: #include <boost/range/begin.hpp>
Chris@16: #include <boost/range/end.hpp>
Chris@16: 
Chris@16: namespace boost { namespace algorithm {
Chris@16: 
Chris@16: /// \fn one_of ( InputIterator first, InputIterator last, Predicate p )
Chris@16: /// \return true if the predicate 'p' is true for exactly one item in [first, last).
Chris@16: /// 
Chris@16: /// \param first The start of the input sequence
Chris@16: /// \param last  One past the end of the input sequence
Chris@16: /// \param p     A predicate for testing the elements of the sequence
Chris@16: ///
Chris@16: template<typename InputIterator, typename Predicate> 
Chris@16: bool one_of ( InputIterator first, InputIterator last, Predicate p )
Chris@16: {
Chris@16:     InputIterator i = std::find_if (first, last, p);
Chris@16:     if (i == last)
Chris@16:         return false;    // Didn't occur at all
Chris@16:     return boost::algorithm::none_of (++i, last, p);
Chris@16: }
Chris@16: 
Chris@16: /// \fn one_of ( const Range &r, Predicate p )
Chris@16: /// \return true if the predicate 'p' is true for exactly one item in the range.
Chris@16: /// 
Chris@16: /// \param r    The input range
Chris@16: /// \param p    A predicate for testing the elements of the range
Chris@16: ///
Chris@16: template<typename Range, typename Predicate> 
Chris@16: bool one_of ( const Range &r, Predicate p ) 
Chris@16: {
Chris@16:     return boost::algorithm::one_of ( boost::begin (r), boost::end (r), p );
Chris@16: }
Chris@16: 
Chris@16: 
Chris@16: /// \fn one_of_equal ( InputIterator first, InputIterator last, const V &val )
Chris@16: /// \return true if the value 'val' exists only once in [first, last).
Chris@16: /// 
Chris@16: /// \param first    The start of the input sequence
Chris@16: /// \param last     One past the end of the input sequence
Chris@16: /// \param val      A value to compare against
Chris@16: ///
Chris@16: template<typename InputIterator, typename V> 
Chris@16: bool one_of_equal ( InputIterator first, InputIterator last, const V &val )
Chris@16: {
Chris@16:     InputIterator i = std::find (first, last, val); // find first occurrence of 'val'
Chris@16:     if (i == last)
Chris@16:         return false;                    // Didn't occur at all
Chris@16:     return boost::algorithm::none_of_equal (++i, last, val);
Chris@16: }
Chris@16: 
Chris@16: /// \fn one_of_equal ( const Range &r, const V &val )
Chris@16: /// \return true if the value 'val' exists only once in the range.
Chris@16: /// 
Chris@16: /// \param r    The input range
Chris@16: /// \param val  A value to compare against
Chris@16: ///
Chris@16: template<typename Range, typename V> 
Chris@16: bool one_of_equal ( const Range &r, const V &val )
Chris@16: {
Chris@16:     return boost::algorithm::one_of_equal ( boost::begin (r), boost::end (r), val );
Chris@16: } 
Chris@16: 
Chris@16: }} // namespace boost and algorithm
Chris@16: 
Chris@16: #endif // BOOST_ALGORITHM_ALL_HPP