Changed the return type for boost::algorithm::copy_while and copy_until to return a pair<InputIterator, OutputIterator> instead of just an OutputIterator

[SVN r83064]

include/boost/algorithm/cxx11/copy_if.hpp

@@ -63,7 +63,7 @@ OutputIterator copy_if ( const Range &r, OutputIterator result, Predicate p )
 /// \fn copy_while ( InputIterator first, InputIterator last, OutputIterator result, Predicate p )
 /// \brief Copies all the elements at the start of the input range that
 ///     satisfy the predicate to the output range.
-/// \return The updated output iterator
+/// \return The updated input and output iterators
 /// 
 /// \param first    The start of the input sequence
 /// \param last     One past the end of the input sequence
@@ -71,25 +71,26 @@ OutputIterator copy_if ( const Range &r, OutputIterator result, Predicate p )
 /// \param p        A predicate for testing the elements of the range
 ///
 template<typename InputIterator, typename OutputIterator, typename Predicate> 
-OutputIterator copy_while ( InputIterator first, InputIterator last, 
+std::pair<InputIterator, OutputIterator>
-                                OutputIterator result, Predicate p )
+copy_while ( InputIterator first, InputIterator last, OutputIterator result, Predicate p )
 {
     for ( ; first != last && p(*first); ++first )
         *result++ = *first;
-    return result;
+    return std::make_pair(first, result);
 }
 
 /// \fn copy_while ( const Range &r, OutputIterator result, Predicate p )
 /// \brief Copies all the elements at the start of the input range that
 ///     satisfy the predicate to the output range.
-/// \return The updated output iterator
+/// \return The updated input and output iterators
 /// 
 /// \param r        The input range
 /// \param result   An output iterator to write the results into
 /// \param p        A predicate for testing the elements of the range
 ///
 template<typename Range, typename OutputIterator, typename Predicate>
-OutputIterator copy_while ( const Range &r, OutputIterator result, Predicate p )
+std::pair<typename boost::range_iterator<const Range>::type, OutputIterator> 
+copy_while ( const Range &r, OutputIterator result, Predicate p )
 {
     return boost::algorithm::copy_while (boost::begin (r), boost::end(r), result, p);
 }
@@ -106,11 +107,12 @@ OutputIterator copy_while ( const Range &r, OutputIterator result, Predicate p )
 /// \param p        A predicate for testing the elements of the range
 ///
 template<typename InputIterator, typename OutputIterator, typename Predicate> 
-OutputIterator copy_until ( InputIterator first, InputIterator last, OutputIterator result, Predicate p )
+std::pair<InputIterator, OutputIterator>
+copy_until ( InputIterator first, InputIterator last, OutputIterator result, Predicate p )
 {
     for ( ; first != last && !p(*first); ++first )
         *result++ = *first;
-    return result;
+    return std::make_pair(first, result);
 }
 
 /// \fn copy_until ( const Range &r, OutputIterator result, Predicate p )
@@ -123,7 +125,8 @@ OutputIterator copy_until ( InputIterator first, InputIterator last, OutputItera
 /// \param p        A predicate for testing the elements of the range
 ///
 template<typename Range, typename OutputIterator, typename Predicate>
-OutputIterator copy_until ( const Range &r, OutputIterator result, Predicate p )
+std::pair<typename boost::range_iterator<const Range>::type, OutputIterator> 
+copy_until ( const Range &r, OutputIterator result, Predicate p )
 {
     return boost::algorithm::copy_until (boost::begin (r), boost::end(r), result, p);
 }

test/copy_if_test1.cpp

@@ -20,6 +20,7 @@
 #include <list>
 
 #include <boost/algorithm/cxx11/all_of.hpp>
+#include <boost/algorithm/cxx11/none_of.hpp>
 
 namespace ba = boost::algorithm;
 // namespace ba = boost;
@@ -30,7 +31,7 @@ bool is_even  ( int v ) { return v % 2 == 0; }
 bool is_odd   ( int v ) { return v % 2 == 1; }
 
 template <typename Container>
-void test_sequence ( Container const &c ) {
+void test_copy_if ( Container const &c ) {
 
     typedef typename Container::value_type value_type;
     std::vector<value_type> v;
@@ -48,13 +49,13 @@ void test_sequence ( Container const &c ) {
     v.clear ();
     ba::copy_if ( c.begin (), c.end (), back_inserter ( v ), is_true);
     BOOST_CHECK ( v.size () == c.size ());
-    BOOST_CHECK ( std::equal ( c.begin (), c.end (), v.begin ()));
+    BOOST_CHECK ( std::equal ( v.begin (), v.end (), c.begin ()));
 
     v.clear ();
     ba::copy_if ( c, back_inserter ( v ), is_true);
     BOOST_CHECK ( v.size () == c.size ());
     BOOST_CHECK ( v.size () == c.size ());
-    BOOST_CHECK ( std::equal ( c.begin (), c.end (), v.begin ()));
+    BOOST_CHECK ( std::equal ( v.begin (), v.end (), c.begin ()));
 
 //  Some of the elements
     v.clear ();
@@ -69,16 +70,106 @@ void test_sequence ( Container const &c ) {
     }
 
 
+template <typename Container>
+void test_copy_while ( Container const &c ) {
+
+    typedef typename Container::value_type value_type;
+    typename Container::const_iterator it;
+    std::vector<value_type> v;
+    
+//  None of the elements
+    v.clear ();
+    ba::copy_while ( c.begin (), c.end (), back_inserter ( v ), is_false);
+    BOOST_CHECK ( v.size () == 0 );
+    
+    v.clear ();
+    ba::copy_while ( c, back_inserter ( v ), is_false);
+    BOOST_CHECK ( v.size () == 0 );
+
+//  All the elements
+    v.clear ();
+    ba::copy_while ( c.begin (), c.end (), back_inserter ( v ), is_true);
+    BOOST_CHECK ( v.size () == c.size ());
+    BOOST_CHECK ( std::equal ( v.begin (), v.end (), c.begin ()));
+
+    v.clear ();
+    ba::copy_while ( c, back_inserter ( v ), is_true);
+    BOOST_CHECK ( v.size () == c.size ());
+    BOOST_CHECK ( std::equal ( v.begin (), v.end (), c.begin ()));
+
+//  Some of the elements
+    v.clear ();
+    it = ba::copy_while ( c.begin (), c.end (), back_inserter ( v ), is_even ).first;
+    BOOST_CHECK ( v.size () == (size_t) std::distance ( c.begin (), it ));
+    BOOST_CHECK ( it == c.end () || !is_even ( *it ));
+    BOOST_CHECK ( ba::all_of ( v.begin (), v.end (), is_even ));
+    BOOST_CHECK ( std::equal ( v.begin (), v.end (), c.begin ()));
+
+    v.clear ();
+    it = ba::copy_while ( c, back_inserter ( v ), is_even ).first;
+    BOOST_CHECK ( v.size () == (size_t) std::distance ( c.begin (), it ));
+    BOOST_CHECK ( it == c.end () || !is_even ( *it ));
+    BOOST_CHECK ( ba::all_of ( v.begin (), v.end (), is_even ));
+    BOOST_CHECK ( std::equal ( v.begin (), v.end (), c.begin ()));
+    }
+
+template <typename Container>
+void test_copy_until ( Container const &c ) {
+
+    typedef typename Container::value_type value_type;
+    typename Container::const_iterator it;
+    std::vector<value_type> v;
+    
+//  None of the elements
+    v.clear ();
+    ba::copy_until ( c.begin (), c.end (), back_inserter ( v ), is_true);
+    BOOST_CHECK ( v.size () == 0 );
+
+    v.clear ();
+    ba::copy_until ( c, back_inserter ( v ), is_true);
+    BOOST_CHECK ( v.size () == 0 );
+
+//  All the elements
+    v.clear ();
+    ba::copy_until ( c.begin (), c.end (), back_inserter ( v ), is_false);
+    BOOST_CHECK ( v.size () == c.size ());
+    BOOST_CHECK ( std::equal ( v.begin (), v.end (), c.begin ()));
+
+    v.clear ();
+    ba::copy_until ( c, back_inserter ( v ), is_false);
+    BOOST_CHECK ( v.size () == c.size ());
+    BOOST_CHECK ( std::equal ( v.begin (), v.end (), c.begin ()));
+
+//  Some of the elements
+    v.clear ();
+    it = ba::copy_until ( c.begin (), c.end (), back_inserter ( v ), is_even ).first;
+    BOOST_CHECK ( v.size () == (size_t) std::distance ( c.begin (), it ));
+    BOOST_CHECK ( it == c.end () || is_even ( *it ));
+    BOOST_CHECK ( ba::none_of ( v.begin (), v.end (), is_even ));
+    BOOST_CHECK ( std::equal ( v.begin (), v.end (), c.begin ()));
+
+    v.clear ();
+    it = ba::copy_until ( c, back_inserter ( v ), is_even ).first;
+    BOOST_CHECK ( v.size () == (size_t) std::distance ( c.begin (), it ));
+    BOOST_CHECK ( it == c.end () || is_even ( *it ));
+    BOOST_CHECK ( ba::none_of ( v.begin (), v.end (), is_even ));
+    BOOST_CHECK ( std::equal ( v.begin (), v.end (), c.begin ()));
+    }
+    
 void test_sequence1 () {
     std::vector<int> v;
     for ( int i = 5; i < 15; ++i )
         v.push_back ( i );
-    test_sequence  ( v );
+    test_copy_if ( v );
+    test_copy_while ( v );
+    test_copy_until ( v );
     
     std::list<int> l;
     for ( int i = 25; i > 15; --i )
         l.push_back ( i );
-    test_sequence  ( l );   
+    test_copy_if ( l );
+    test_copy_while ( l );
+    test_copy_until ( l );
     }