| /* |
| 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) |
| |
| Revision history: |
| 27 June 2009 mtc First version |
| 23 Oct 2010 mtc Added predicate version |
| |
| */ |
| |
| /// \file clamp.hpp |
| /// \brief Clamp algorithm |
| /// \author Marshall Clow |
| /// |
| /// Suggested by olafvdspek in https://svn.boost.org/trac/boost/ticket/3215 |
| |
| #ifndef BOOST_ALGORITHM_CLAMP_HPP |
| #define BOOST_ALGORITHM_CLAMP_HPP |
| |
| #include <functional> // For std::less |
| #include <iterator> // For std::iterator_traits |
| #include <cassert> |
| |
| #include <boost/range/begin.hpp> |
| #include <boost/range/end.hpp> |
| #include <boost/mpl/identity.hpp> // for identity |
| #include <boost/utility/enable_if.hpp> // for boost::disable_if |
| |
| namespace boost { namespace algorithm { |
| |
| /// \fn clamp ( T const& val, |
| /// typename boost::mpl::identity<T>::type const & lo, |
| /// typename boost::mpl::identity<T>::type const & hi, Pred p ) |
| /// \return the value "val" brought into the range [ lo, hi ] |
| /// using the comparison predicate p. |
| /// If p ( val, lo ) return lo. |
| /// If p ( hi, val ) return hi. |
| /// Otherwise, return the original value. |
| /// |
| /// \param val The value to be clamped |
| /// \param lo The lower bound of the range to be clamped to |
| /// \param hi The upper bound of the range to be clamped to |
| /// \param p A predicate to use to compare the values. |
| /// p ( a, b ) returns a boolean. |
| /// |
| template<typename T, typename Pred> |
| T const & clamp ( T const& val, |
| typename boost::mpl::identity<T>::type const & lo, |
| typename boost::mpl::identity<T>::type const & hi, Pred p ) |
| { |
| // assert ( !p ( hi, lo )); // Can't assert p ( lo, hi ) b/c they might be equal |
| return p ( val, lo ) ? lo : p ( hi, val ) ? hi : val; |
| } |
| |
| |
| /// \fn clamp ( T const& val, |
| /// typename boost::mpl::identity<T>::type const & lo, |
| /// typename boost::mpl::identity<T>::type const & hi ) |
| /// \return the value "val" brought into the range [ lo, hi ]. |
| /// If the value is less than lo, return lo. |
| /// If the value is greater than "hi", return hi. |
| /// Otherwise, return the original value. |
| /// |
| /// \param val The value to be clamped |
| /// \param lo The lower bound of the range to be clamped to |
| /// \param hi The upper bound of the range to be clamped to |
| /// |
| template<typename T> |
| T const& clamp ( const T& val, |
| typename boost::mpl::identity<T>::type const & lo, |
| typename boost::mpl::identity<T>::type const & hi ) |
| { |
| return (clamp) ( val, lo, hi, std::less<T>()); |
| } |
| |
| /// \fn clamp_range ( InputIterator first, InputIterator last, OutputIterator out, |
| /// std::iterator_traits<InputIterator>::value_type const & lo, |
| /// std::iterator_traits<InputIterator>::value_type const & hi ) |
| /// \return clamp the sequence of values [first, last) into [ lo, hi ] |
| /// |
| /// \param first The start of the range of values |
| /// \param last One past the end of the range of input values |
| /// \param out An output iterator to write the clamped values into |
| /// \param lo The lower bound of the range to be clamped to |
| /// \param hi The upper bound of the range to be clamped to |
| /// |
| template<typename InputIterator, typename OutputIterator> |
| OutputIterator clamp_range ( InputIterator first, InputIterator last, OutputIterator out, |
| typename std::iterator_traits<InputIterator>::value_type const & lo, |
| typename std::iterator_traits<InputIterator>::value_type const & hi ) |
| { |
| // this could also be written with bind and std::transform |
| while ( first != last ) |
| *out++ = clamp ( *first++, lo, hi ); |
| return out; |
| } |
| |
| /// \fn clamp_range ( const Range &r, OutputIterator out, |
| /// typename std::iterator_traits<typename boost::range_iterator<const Range>::type>::value_type const & lo, |
| /// typename std::iterator_traits<typename boost::range_iterator<const Range>::type>::value_type const & hi ) |
| /// \return clamp the sequence of values [first, last) into [ lo, hi ] |
| /// |
| /// \param r The range of values to be clamped |
| /// \param out An output iterator to write the clamped values into |
| /// \param lo The lower bound of the range to be clamped to |
| /// \param hi The upper bound of the range to be clamped to |
| /// |
| template<typename Range, typename OutputIterator> |
| typename boost::disable_if_c<boost::is_same<Range, OutputIterator>::value, OutputIterator>::type |
| clamp_range ( const Range &r, OutputIterator out, |
| typename std::iterator_traits<typename boost::range_iterator<const Range>::type>::value_type const & lo, |
| typename std::iterator_traits<typename boost::range_iterator<const Range>::type>::value_type const & hi ) |
| { |
| return clamp_range ( boost::begin ( r ), boost::end ( r ), out, lo, hi ); |
| } |
| |
| |
| /// \fn clamp_range ( InputIterator first, InputIterator last, OutputIterator out, |
| /// std::iterator_traits<InputIterator>::value_type const & lo, |
| /// std::iterator_traits<InputIterator>::value_type const & hi, Pred p ) |
| /// \return clamp the sequence of values [first, last) into [ lo, hi ] |
| /// using the comparison predicate p. |
| /// |
| /// \param first The start of the range of values |
| /// \param last One past the end of the range of input values |
| /// \param out An output iterator to write the clamped values into |
| /// \param lo The lower bound of the range to be clamped to |
| /// \param hi The upper bound of the range to be clamped to |
| /// \param p A predicate to use to compare the values. |
| /// p ( a, b ) returns a boolean. |
| |
| /// |
| template<typename InputIterator, typename OutputIterator, typename Pred> |
| OutputIterator clamp_range ( InputIterator first, InputIterator last, OutputIterator out, |
| typename std::iterator_traits<InputIterator>::value_type const & lo, |
| typename std::iterator_traits<InputIterator>::value_type const & hi, Pred p ) |
| { |
| // this could also be written with bind and std::transform |
| while ( first != last ) |
| *out++ = clamp ( *first++, lo, hi, p ); |
| return out; |
| } |
| |
| /// \fn clamp_range ( const Range &r, OutputIterator out, |
| /// typename std::iterator_traits<typename boost::range_iterator<const Range>::type>::value_type const & lo, |
| /// typename std::iterator_traits<typename boost::range_iterator<const Range>::type>::value_type const & hi, |
| /// Pred p ) |
| /// \return clamp the sequence of values [first, last) into [ lo, hi ] |
| /// using the comparison predicate p. |
| /// |
| /// \param r The range of values to be clamped |
| /// \param out An output iterator to write the clamped values into |
| /// \param lo The lower bound of the range to be clamped to |
| /// \param hi The upper bound of the range to be clamped to |
| /// \param p A predicate to use to compare the values. |
| /// p ( a, b ) returns a boolean. |
| // |
| // Disable this template if the first two parameters are the same type; |
| // In that case, the user will get the two iterator version. |
| template<typename Range, typename OutputIterator, typename Pred> |
| typename boost::disable_if_c<boost::is_same<Range, OutputIterator>::value, OutputIterator>::type |
| clamp_range ( const Range &r, OutputIterator out, |
| typename std::iterator_traits<typename boost::range_iterator<const Range>::type>::value_type const & lo, |
| typename std::iterator_traits<typename boost::range_iterator<const Range>::type>::value_type const & hi, |
| Pred p ) |
| { |
| return clamp_range ( boost::begin ( r ), boost::end ( r ), out, lo, hi, p ); |
| } |
| |
| |
| }} |
| |
| #endif // BOOST_ALGORITHM_CLAMP_HPP |