Preparation for V5.

include/boost/regex/v5/regex_split.hpp

@@ -0,0 +1,174 @@
+/*
+ *
+ * Copyright (c) 1998-2002
+ * John Maddock
+ *
+ * Use, modification and distribution are subject to 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)
+ *
+ */
+ 
+ /*
+  *   LOCATION:    see http://www.boost.org for most recent version.
+  *   FILE         regex_split.hpp
+  *   VERSION      see <boost/version.hpp>
+  *   DESCRIPTION: Implements regex_split and associated functions.
+  *                Note this is an internal header file included
+  *                by regex.hpp, do not include on its own.
+  */
+
+#ifndef BOOST_REGEX_SPLIT_HPP
+#define BOOST_REGEX_SPLIT_HPP
+
+namespace boost{
+
+#ifdef BOOST_MSVC
+#pragma warning(push)
+#pragma warning(disable: 4103)
+#endif
+#ifdef BOOST_HAS_ABI_HEADERS
+#  include BOOST_ABI_PREFIX
+#endif
+#ifdef BOOST_MSVC
+#pragma warning(pop)
+#endif
+
+#ifdef BOOST_MSVC
+#  pragma warning(push)
+#if BOOST_MSVC < 1910
+#pragma warning(disable:4800)
+#endif
+#endif
+
+namespace BOOST_REGEX_DETAIL_NS{
+
+template <class charT>
+const basic_regex<charT>& get_default_expression(charT)
+{
+   static const charT expression_text[4] = { '\\', 's', '+', '\00', };
+   static const basic_regex<charT> e(expression_text);
+   return e;
+}
+
+template <class OutputIterator, class charT, class Traits1, class Alloc1>
+class split_pred
+{
+   typedef std::basic_string<charT, Traits1, Alloc1> string_type;
+   typedef typename string_type::const_iterator iterator_type;
+   iterator_type* p_last;
+   OutputIterator* p_out;
+   std::size_t* p_max;
+   std::size_t initial_max;
+public:
+   split_pred(iterator_type* a, OutputIterator* b, std::size_t* c)
+      : p_last(a), p_out(b), p_max(c), initial_max(*c) {}
+
+   bool operator()(const match_results<iterator_type>& what);
+};
+
+template <class OutputIterator, class charT, class Traits1, class Alloc1>
+bool split_pred<OutputIterator, charT, Traits1, Alloc1>::operator()
+   (const match_results<iterator_type>& what)
+{
+   *p_last = what[0].second;
+   if(what.size() > 1)
+   {
+      // output sub-expressions only:
+      for(unsigned i = 1; i < what.size(); ++i)
+      {
+         *(*p_out) = what.str(i);
+         ++(*p_out);
+         if(0 == --*p_max) return false;
+      }
+      return *p_max != 0;
+   }
+   else
+   {
+      // output $` only if it's not-null or not at the start of the input:
+      const sub_match<iterator_type>& sub = what[-1];
+      if((sub.first != sub.second) || (*p_max != initial_max))
+      {
+         *(*p_out) = sub.str();
+         ++(*p_out);
+         return --*p_max;
+      }
+   }
+   //
+   // initial null, do nothing:
+   return true;
+}
+
+} // namespace BOOST_REGEX_DETAIL_NS
+
+template <class OutputIterator, class charT, class Traits1, class Alloc1, class Traits2>
+std::size_t regex_split(OutputIterator out,
+                   std::basic_string<charT, Traits1, Alloc1>& s, 
+                   const basic_regex<charT, Traits2>& e,
+                   match_flag_type flags,
+                   std::size_t max_split)
+{
+   typedef typename std::basic_string<charT, Traits1, Alloc1>::const_iterator  ci_t;
+   //typedef typename match_results<ci_t>::allocator_type                        match_allocator;
+   ci_t last = s.begin();
+   std::size_t init_size = max_split;
+   BOOST_REGEX_DETAIL_NS::split_pred<OutputIterator, charT, Traits1, Alloc1> pred(&last, &out, &max_split);
+   ci_t i, j;
+   i = s.begin();
+   j = s.end();
+   regex_grep(pred, i, j, e, flags);
+   //
+   // if there is still input left, do a final push as long as max_split
+   // is not exhausted, and we're not splitting sub-expressions rather 
+   // than whitespace:
+   if(max_split && (last != s.end()) && (e.mark_count() == 0))
+   {
+      *out = std::basic_string<charT, Traits1, Alloc1>((ci_t)last, (ci_t)s.end());
+      ++out;
+      last = s.end();
+      --max_split;
+   }
+   //
+   // delete from the string everything that has been processed so far:
+   s.erase(0, last - s.begin());
+   //
+   // return the number of new records pushed:
+   return init_size - max_split;
+}
+
+template <class OutputIterator, class charT, class Traits1, class Alloc1, class Traits2>
+inline std::size_t regex_split(OutputIterator out,
+                   std::basic_string<charT, Traits1, Alloc1>& s, 
+                   const basic_regex<charT, Traits2>& e,
+                   match_flag_type flags = match_default)
+{
+   return regex_split(out, s, e, flags, UINT_MAX);
+}
+
+template <class OutputIterator, class charT, class Traits1, class Alloc1>
+inline std::size_t regex_split(OutputIterator out,
+                   std::basic_string<charT, Traits1, Alloc1>& s)
+{
+   return regex_split(out, s, BOOST_REGEX_DETAIL_NS::get_default_expression(charT(0)), match_default, UINT_MAX);
+}
+
+#ifdef BOOST_MSVC
+#  pragma warning(pop)
+#endif
+
+#ifdef BOOST_MSVC
+#pragma warning(push)
+#pragma warning(disable: 4103)
+#endif
+#ifdef BOOST_HAS_ABI_HEADERS
+#  include BOOST_ABI_SUFFIX
+#endif
+#ifdef BOOST_MSVC
+#pragma warning(pop)
+#endif
+
+} // namespace boost
+
+#endif
+
+