Merge pull request #100 from jgopel/copy-if-while

Implement copy_if_while and copy_if_until

Author: mclow

doc/algorithm.qbk

@@ -216,14 +216,24 @@ See below
 
 [section:copy_until                copy_until                ]
 [*[^[link header.boost.algorithm.cxx11.copy_if_hpp                   copy_until]                  ] ]
-Copy all the elements at the start of the input range that do not satisfy the predicate to the output range
+Copy all the elements from the start of the input range to the output range until the predicate is satisfied
 [endsect:copy_until]
 
 [section:copy_while                copy_while                ]
 [*[^[link header.boost.algorithm.cxx11.copy_if_hpp                   copy_while]                  ] ]
-Copy all the elements at the start of the input range that satisfy the predicate to the output range
+Copy all the elements from the start of the input range to the output range while the predicate is satisfied
 [endsect:copy_while]
 
+[section:copy_if_until             copy_if_until             ]
+[*[^[link header.boost.algorithm.cxx11.copy_if_hpp                   copy_if_until                ] ]
+Copy all elements that satisfy the element predicate from the start of the input range to the output range until the termination predicate is satisfied
+[endsect:copy_if_until]
+
+[section:copy_if_while             copy_if_while             ]
+[*[^[link header.boost.algorithm.cxx11.copy_if_hpp                   copy_if_while                ] ]
+Copy all elements that satisfy the element predicate from the start of the input range to the output range while the termination predicate is satisfied
+[endsect:copy_if_while]
+
 [section:iota_n                    iota_n                    ]
 [*[^[link boost.algorithm.iota_n                                     iota_n]                      ] ]
 Write a sequence of n increasing values to an output iterator

include/boost/algorithm/cxx11/copy_if.hpp

@@ -126,6 +126,86 @@ copy_until ( const Range &r, OutputIterator result, Predicate p )
     return boost::algorithm::copy_until (boost::begin (r), boost::end(r), result, p);
 }
 
+/// \fn copy_if_while ( InputIterator first, InputIterator last, OutputIterator result, CopyPredicate copy_pred, TerminatePred term_pred )
+/// \brief Copies all the elements from the input range that satisfy the
+/// copy predicate to the output range while the termination predicate is
+/// satisfied.
+/// \return The updated output iterator
+///
+/// \param first     The start of the input sequence
+/// \param last      One past the end of the input sequence
+/// \param result    An output iterator to write the results into
+/// \param copy_pred A predicate for testing whether to the current element
+/// \param term_pred A predicate for testing whether to end the copy operation
+template<typename InputIterator, typename OutputIterator, typename CopyPredicate, typename TerminatePred>
+BOOST_CXX14_CONSTEXPR std::pair<InputIterator, OutputIterator>
+copy_if_while ( InputIterator first, InputIterator last, OutputIterator result, CopyPredicate copy_pred, TerminatePred term_pred)
+{
+    for ( ; first != last && term_pred(*first); ++first ) {
+        if (copy_pred(*first)) {
+            *result++ = *first;
+        }
+    }
+    return std::make_pair(first, result);
+}
+
+/// \fn copy_if_while ( const Range& r, OutputIterator result, CopyPredicate copy_pred, TerminatePred term_pred )
+/// \brief Copies all the elements from the input range that satisfy the
+/// copy predicate to the output range while the termination predicate is
+/// satisfied.
+/// \return The updated output iterator
+///
+/// \param r         The input range
+/// \param result    An output iterator to write the results into
+/// \param copy_pred A predicate for testing whether to the current element
+/// \param term_pred A predicate for testing whether to end the copy operation
+template<typename Range, typename OutputIterator, typename CopyPredicate, typename TerminatePred>
+BOOST_CXX14_CONSTEXPR std::pair<typename boost::range_iterator<const Range>::type, OutputIterator>
+copy_if_while ( const Range& r, OutputIterator result, CopyPredicate copy_pred, TerminatePred term_pred)
+{
+    return boost::algorithm::copy_if_while(boost::begin(r), boost::end(r), result, copy_pred, term_pred);
+}
+
+/// \fn copy_if_until ( InputIterator first, InputIterator last, OutputIterator result, CopyPredicate copy_pred, TerminatePred term_pred )
+/// \brief Copies all the elements from the input range that satisfy the
+/// copy predicate to the output range until the termination predicate is
+/// satisfied.
+/// \return The updated output iterator
+///
+/// \param first     The start of the input sequence
+/// \param last      One past the end of the input sequence
+/// \param result    An output iterator to write the results into
+/// \param copy_pred A predicate for testing whether to the current element
+/// \param term_pred A predicate for testing whether to end the copy operation
+template<typename InputIterator, typename OutputIterator, typename CopyPredicate, typename TerminatePred>
+BOOST_CXX14_CONSTEXPR std::pair<InputIterator, OutputIterator>
+copy_if_until ( InputIterator first, InputIterator last, OutputIterator result, CopyPredicate copy_pred, TerminatePred term_pred)
+{
+    for ( ; first != last && !term_pred(*first); ++first ) {
+        if (copy_pred(*first)) {
+            *result++ = *first;
+        }
+    }
+    return std::make_pair(first, result);
+}
+
+/// \fn copy_if_until ( const Range& r, OutputIterator result, CopyPredicate copy_pred, TerminatePred term_pred )
+/// \brief Copies all the elements from the input range that satisfy the
+/// copy predicate to the output range until the termination predicate is
+/// satisfied.
+/// \return The updated output iterator
+///
+/// \param r         The input range
+/// \param result    An output iterator to write the results into
+/// \param copy_pred A predicate for testing whether to the current element
+/// \param term_pred A predicate for testing whether to end the copy operation
+template<typename Range, typename OutputIterator, typename CopyPredicate, typename TerminatePred>
+BOOST_CXX14_CONSTEXPR std::pair<typename boost::range_iterator<const Range>::type, OutputIterator>
+copy_if_until ( const Range& r, OutputIterator result, CopyPredicate copy_pred, TerminatePred term_pred)
+{
+    return boost::algorithm::copy_if_until(boost::begin(r), boost::end(r), result, copy_pred, term_pred);
+}
+
 }} // namespace boost and algorithm
 
 #endif  // BOOST_ALGORITHM_COPY_IF_HPP