Imported Upstream version 4.0.0upstream/4.0.0

1 files changed, 2874 insertions, 0 deletions

diff --git a/libcutl/cutl/details/boost/regex/v4/basic_regex_parser.hpp b/libcutl/cutl/details/boost/regex/v4/basic_regex_parser.hpp
new file mode 100644
index 0000000..9182da2
--- /dev/null
+++ b/libcutl/cutl/details/boost/regex/v4/basic_regex_parser.hpp
@@ -0,0 +1,2874 @@
+/*
+ *
+ * Copyright (c) 2004
+ * 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         basic_regex_parser.cpp
+  *   VERSION      see <cutl/details/boost/version.hpp>
+  *   DESCRIPTION: Declares template class basic_regex_parser.
+  */
+
+#ifndef BOOST_REGEX_V4_BASIC_REGEX_PARSER_HPP
+#define BOOST_REGEX_V4_BASIC_REGEX_PARSER_HPP
+
+#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
+
+namespace cutl_details_boost{
+namespace re_detail{
+
+#ifdef BOOST_MSVC
+#pragma warning(push)
+#pragma warning(disable:4244 4800)
+#endif
+
+template <class charT, class traits>
+class basic_regex_parser : public basic_regex_creator<charT, traits>
+{
+public:
+   basic_regex_parser(regex_data<charT, traits>* data);
+   void parse(const charT* p1, const charT* p2, unsigned flags);
+   void fail(regex_constants::error_type error_code, std::ptrdiff_t position);
+   void fail(regex_constants::error_type error_code, std::ptrdiff_t position, std::string message, std::ptrdiff_t start_pos);
+   void fail(regex_constants::error_type error_code, std::ptrdiff_t position, const std::string& message)
+   {
+      fail(error_code, position, message, position);
+   }
+
+   bool parse_all();
+   bool parse_basic();
+   bool parse_extended();
+   bool parse_literal();
+   bool parse_open_paren();
+   bool parse_basic_escape();
+   bool parse_extended_escape();
+   bool parse_match_any();
+   bool parse_repeat(std::size_t low = 0, std::size_t high = (std::numeric_limits<std::size_t>::max)());
+   bool parse_repeat_range(bool isbasic);
+   bool parse_alt();
+   bool parse_set();
+   bool parse_backref();
+   void parse_set_literal(basic_char_set<charT, traits>& char_set);
+   bool parse_inner_set(basic_char_set<charT, traits>& char_set);
+   bool parse_QE();
+   bool parse_perl_extension();
+   bool add_emacs_code(bool negate);
+   bool unwind_alts(std::ptrdiff_t last_paren_start);
+   digraph<charT> get_next_set_literal(basic_char_set<charT, traits>& char_set);
+   charT unescape_character();
+   regex_constants::syntax_option_type parse_options();
+
+private:
+   typedef bool (basic_regex_parser::*parser_proc_type)();
+   typedef typename traits::string_type string_type;
+   typedef typename traits::char_class_type char_class_type;
+   parser_proc_type           m_parser_proc;    // the main parser to use
+   const charT*               m_base;           // the start of the string being parsed
+   const charT*               m_end;            // the end of the string being parsed
+   const charT*               m_position;       // our current parser position
+   unsigned                   m_mark_count;     // how many sub-expressions we have
+   int                        m_mark_reset;     // used to indicate that we're inside a (?|...) block.
+   unsigned                   m_max_mark;       // largest mark count seen inside a (?|...) block.
+   std::ptrdiff_t             m_paren_start;    // where the last seen ')' began (where repeats are inserted).
+   std::ptrdiff_t             m_alt_insert_point; // where to insert the next alternative
+   bool                       m_has_case_change; // true if somewhere in the current block the case has changed
+#if defined(BOOST_MSVC) && defined(_M_IX86)
+   // This is an ugly warning suppression workaround (for warnings *inside* std::vector
+   // that can not otherwise be suppressed)...
+   BOOST_STATIC_ASSERT(sizeof(long) >= sizeof(void*));
+   std::vector<long>           m_alt_jumps;      // list of alternative in the current scope.
+#else
+   std::vector<std::ptrdiff_t> m_alt_jumps;      // list of alternative in the current scope.
+#endif
+
+   basic_regex_parser& operator=(const basic_regex_parser&);
+   basic_regex_parser(const basic_regex_parser&);
+};
+
+template <class charT, class traits>
+basic_regex_parser<charT, traits>::basic_regex_parser(regex_data<charT, traits>* data)
+   : basic_regex_creator<charT, traits>(data), m_mark_count(0), m_mark_reset(-1), m_max_mark(0), m_paren_start(0), m_alt_insert_point(0), m_has_case_change(false)
+{
+}
+
+template <class charT, class traits>
+void basic_regex_parser<charT, traits>::parse(const charT* p1, const charT* p2, unsigned l_flags)
+{
+   // pass l_flags on to base class:
+   this->init(l_flags);
+   // set up pointers:
+   m_position = m_base = p1;
+   m_end = p2;
+   // empty strings are errors:
+   if((p1 == p2) && 
+      (
+         ((l_flags & regbase::main_option_type) != regbase::perl_syntax_group)
+         || (l_flags & regbase::no_empty_expressions)
+      )
+     )
+   {
+      fail(regex_constants::error_empty, 0);
+      return;
+   }
+   // select which parser to use:
+   switch(l_flags & regbase::main_option_type)
+   {
+   case regbase::perl_syntax_group:
+      {
+         m_parser_proc = &basic_regex_parser<charT, traits>::parse_extended;
+         //
+         // Add a leading paren with index zero to give recursions a target:
+         //
+         re_brace* br = static_cast<re_brace*>(this->append_state(syntax_element_startmark, sizeof(re_brace)));
+         br->index = 0;
+         br->icase = this->flags() & regbase::icase;
+         break;
+      }
+   case regbase::basic_syntax_group:
+      m_parser_proc = &basic_regex_parser<charT, traits>::parse_basic;
+      break;
+   case regbase::literal:
+      m_parser_proc = &basic_regex_parser<charT, traits>::parse_literal;
+      break;
+   default:
+      // Ooops, someone has managed to set more than one of the main option flags, 
+      // so this must be an error:
+      fail(regex_constants::error_unknown, 0, "An invalid combination of regular expression syntax flags was used.");
+      return;
+   }
+
+   // parse all our characters:
+   bool result = parse_all();
+   //
+   // Unwind our alternatives:
+   //
+   unwind_alts(-1);
+   // reset l_flags as a global scope (?imsx) may have altered them:
+   this->flags(l_flags);
+   // if we haven't gobbled up all the characters then we must
+   // have had an unexpected ')' :
+   if(!result)
+   {
+      fail(regex_constants::error_paren, ::cutl_details_boost::re_detail::distance(m_base, m_position), "Found a closing ) with no corresponding openening parenthesis.");
+      return;
+   }
+   // if an error has been set then give up now:
+   if(this->m_pdata->m_status)
+      return;
+   // fill in our sub-expression count:
+   this->m_pdata->m_mark_count = 1 + m_mark_count;
+   this->finalize(p1, p2);
+}
+
+template <class charT, class traits>
+void basic_regex_parser<charT, traits>::fail(regex_constants::error_type error_code, std::ptrdiff_t position)
+{
+   // get the error message:
+   std::string message = this->m_pdata->m_ptraits->error_string(error_code);
+   fail(error_code, position, message);
+}
+
+template <class charT, class traits>
+void basic_regex_parser<charT, traits>::fail(regex_constants::error_type error_code, std::ptrdiff_t position, std::string message, std::ptrdiff_t start_pos)
+{
+   if(0 == this->m_pdata->m_status) // update the error code if not already set
+      this->m_pdata->m_status = error_code;
+   m_position = m_end; // don't bother parsing anything else
+
+#ifndef BOOST_NO_TEMPLATED_ITERATOR_CONSTRUCTORS
+   //
+   // Augment error message with the regular expression text:
+   //
+   if(start_pos == position)
+      start_pos = (std::max)(static_cast<std::ptrdiff_t>(0), position - static_cast<std::ptrdiff_t>(10));
+   std::ptrdiff_t end_pos = (std::min)(position + static_cast<std::ptrdiff_t>(10), static_cast<std::ptrdiff_t>(m_end - m_base));
+   if(error_code != regex_constants::error_empty)
+   {
+      if((start_pos != 0) || (end_pos != (m_end - m_base)))
+         message += "  The error occurred while parsing the regular expression fragment: '";
+      else
+         message += "  The error occurred while parsing the regular expression: '";
+      if(start_pos != end_pos)
+      {
+         message += std::string(m_base + start_pos, m_base + position);
+         message += ">>>HERE>>>";
+         message += std::string(m_base + position, m_base + end_pos);
+      }
+      message += "'.";
+   }
+#endif
+
+#ifndef BOOST_NO_EXCEPTIONS
+   if(0 == (this->flags() & regex_constants::no_except))
+   {
+      cutl_details_boost::regex_error e(message, error_code, position);
+      e.raise();
+   }
+#else
+   (void)position; // suppress warnings.
+#endif
+}
+
+template <class charT, class traits>
+bool basic_regex_parser<charT, traits>::parse_all()
+{
+   bool result = true;
+   while(result && (m_position != m_end))
+   {
+      result = (this->*m_parser_proc)();
+   }
+   return result;
+}
+
+#ifdef BOOST_MSVC
+#pragma warning(push)
+#pragma warning(disable:4702)
+#endif
+template <class charT, class traits>
+bool basic_regex_parser<charT, traits>::parse_basic()
+{
+   switch(this->m_traits.syntax_type(*m_position))
+   {
+   case regex_constants::syntax_escape:
+      return parse_basic_escape();
+   case regex_constants::syntax_dot:
+      return parse_match_any();
+   case regex_constants::syntax_caret:
+      ++m_position;
+      this->append_state(syntax_element_start_line);
+      break;
+   case regex_constants::syntax_dollar:
+      ++m_position;
+      this->append_state(syntax_element_end_line);
+      break;
+   case regex_constants::syntax_star:
+      if(!(this->m_last_state) || (this->m_last_state->type == syntax_element_start_line))
+         return parse_literal();
+      else
+      {
+         ++m_position;
+         return parse_repeat();
+      }
+   case regex_constants::syntax_plus:
+      if(!(this->m_last_state) || (this->m_last_state->type == syntax_element_start_line) || !(this->flags() & regbase::emacs_ex))
+         return parse_literal();
+      else
+      {
+         ++m_position;
+         return parse_repeat(1);
+      }
+   case regex_constants::syntax_question:
+      if(!(this->m_last_state) || (this->m_last_state->type == syntax_element_start_line) || !(this->flags() & regbase::emacs_ex))
+         return parse_literal();
+      else
+      {
+         ++m_position;
+         return parse_repeat(0, 1);
+      }
+   case regex_constants::syntax_open_set:
+      return parse_set();
+   case regex_constants::syntax_newline:
+      if(this->flags() & regbase::newline_alt)
+         return parse_alt();
+      else
+         return parse_literal();
+   default:
+      return parse_literal();
+   }
+   return true;
+}
+
+template <class charT, class traits>
+bool basic_regex_parser<charT, traits>::parse_extended()
+{
+   bool result = true;
+   switch(this->m_traits.syntax_type(*m_position))
+   {
+   case regex_constants::syntax_open_mark:
+      return parse_open_paren();
+   case regex_constants::syntax_close_mark:
+      return false;
+   case regex_constants::syntax_escape:
+      return parse_extended_escape();
+   case regex_constants::syntax_dot:
+      return parse_match_any();
+   case regex_constants::syntax_caret:
+      ++m_position;
+      this->append_state(
+         (this->flags() & regex_constants::no_mod_m ? syntax_element_buffer_start : syntax_element_start_line));
+      break;
+   case regex_constants::syntax_dollar:
+      ++m_position;
+      this->append_state(
+         (this->flags() & regex_constants::no_mod_m ? syntax_element_buffer_end : syntax_element_end_line));
+      break;
+   case regex_constants::syntax_star:
+      if(m_position == this->m_base)
+      {
+         fail(regex_constants::error_badrepeat, 0, "The repeat operator \"*\" cannot start a regular expression.");
+         return false;
+      }
+      ++m_position;
+      return parse_repeat();
+   case regex_constants::syntax_question:
+      if(m_position == this->m_base)
+      {
+         fail(regex_constants::error_badrepeat, 0, "The repeat operator \"?\" cannot start a regular expression.");
+         return false;
+      }
+      ++m_position;
+      return parse_repeat(0,1);
+   case regex_constants::syntax_plus:
+      if(m_position == this->m_base)
+      {
+         fail(regex_constants::error_badrepeat, 0, "The repeat operator \"+\" cannot start a regular expression.");
+         return false;
+      }
+      ++m_position;
+      return parse_repeat(1);
+   case regex_constants::syntax_open_brace:
+      ++m_position;
+      return parse_repeat_range(false);
+   case regex_constants::syntax_close_brace:
+      fail(regex_constants::error_brace, this->m_position - this->m_base, "Found a closing repetition operator } with no corresponding {.");
+      return false;
+   case regex_constants::syntax_or:
+      return parse_alt();
+   case regex_constants::syntax_open_set:
+      return parse_set();
+   case regex_constants::syntax_newline:
+      if(this->flags() & regbase::newline_alt)
+         return parse_alt();
+      else
+         return parse_literal();
+   case regex_constants::syntax_hash:
+      //
+      // If we have a mod_x flag set, then skip until
+      // we get to a newline character:
+      //
+      if((this->flags() 
+         & (regbase::no_perl_ex|regbase::mod_x))
+         == regbase::mod_x)
+      {
+         while((m_position != m_end) && !is_separator(*m_position++)){}
+         return true;
+      }
+      BOOST_FALLTHROUGH;
+   default:
+      result = parse_literal();
+      break;
+   }
+   return result;
+}
+#ifdef BOOST_MSVC
+#pragma warning(pop)
+#endif
+
+template <class charT, class traits>
+bool basic_regex_parser<charT, traits>::parse_literal()
+{
+   // append this as a literal provided it's not a space character
+   // or the perl option regbase::mod_x is not set:
+   if(
+      ((this->flags() 
+         & (regbase::main_option_type|regbase::mod_x|regbase::no_perl_ex)) 
+            != regbase::mod_x)
+      || !this->m_traits.isctype(*m_position, this->m_mask_space))
+         this->append_literal(*m_position);
+   ++m_position;
+   return true;
+}
+
+template <class charT, class traits>
+bool basic_regex_parser<charT, traits>::parse_open_paren()
+{
+   //
+   // skip the '(' and error check:
+   //
+   if(++m_position == m_end)
+   {
+      fail(regex_constants::error_paren, m_position - m_base);
+      return false;
+   }
+   //
+   // begin by checking for a perl-style (?...) extension:
+   //
+   if(
+         ((this->flags() & (regbase::main_option_type | regbase::no_perl_ex)) == 0)
+         || ((this->flags() & (regbase::main_option_type | regbase::emacs_ex)) == (regbase::basic_syntax_group|regbase::emacs_ex))
+     )
+   {
+      if(this->m_traits.syntax_type(*m_position) == regex_constants::syntax_question)
+         return parse_perl_extension();
+   }
+   //
+   // update our mark count, and append the required state:
+   //
+   unsigned markid = 0;
+   if(0 == (this->flags() & regbase::nosubs))
+   {
+      markid = ++m_mark_count;
+#ifndef BOOST_NO_STD_DISTANCE
+      if(this->flags() & regbase::save_subexpression_location)
+         this->m_pdata->m_subs.push_back(std::pair<std::size_t, std::size_t>(std::distance(m_base, m_position) - 1, 0));
+#else
+      if(this->flags() & regbase::save_subexpression_location)
+         this->m_pdata->m_subs.push_back(std::pair<std::size_t, std::size_t>((m_position - m_base) - 1, 0));
+#endif
+   }
+   re_brace* pb = static_cast<re_brace*>(this->append_state(syntax_element_startmark, sizeof(re_brace)));
+   pb->index = markid;
+   pb->icase = this->flags() & regbase::icase;
+   std::ptrdiff_t last_paren_start = this->getoffset(pb);
+   // back up insertion point for alternations, and set new point:
+   std::ptrdiff_t last_alt_point = m_alt_insert_point;
+   this->m_pdata->m_data.align();
+   m_alt_insert_point = this->m_pdata->m_data.size();
+   //
+   // back up the current flags in case we have a nested (?imsx) group:
+   //
+   regex_constants::syntax_option_type opts = this->flags();
+   bool old_case_change = m_has_case_change;
+   m_has_case_change = false; // no changes to this scope as yet...
+   //
+   // Back up branch reset data in case we have a nested (?|...)
+   //
+   int mark_reset = m_mark_reset;
+   m_mark_reset = -1;
+   //
+   // now recursively add more states, this will terminate when we get to a
+   // matching ')' :
+   //
+   parse_all();
+   //
+   // Unwind pushed alternatives:
+   //
+   if(0 == unwind_alts(last_paren_start))
+      return false;
+   //
+   // restore flags:
+   //
+   if(m_has_case_change)
+   {
+      // the case has changed in one or more of the alternatives
+      // within the scoped (...) block: we have to add a state
+      // to reset the case sensitivity:
+      static_cast<re_case*>(
+         this->append_state(syntax_element_toggle_case, sizeof(re_case))
+         )->icase = opts & regbase::icase;
+   }
+   this->flags(opts);
+   m_has_case_change = old_case_change;
+   //
+   // restore branch reset:
+   //
+   m_mark_reset = mark_reset;
+   //
+   // we either have a ')' or we have run out of characters prematurely:
+   //
+   if(m_position == m_end)
+   {
+      this->fail(regex_constants::error_paren, ::cutl_details_boost::re_detail::distance(m_base, m_end));
+      return false;
+   }
+   BOOST_ASSERT(this->m_traits.syntax_type(*m_position) == regex_constants::syntax_close_mark);
+#ifndef BOOST_NO_STD_DISTANCE
+   if(markid && (this->flags() & regbase::save_subexpression_location))
+      this->m_pdata->m_subs.at(markid - 1).second = std::distance(m_base, m_position);
+#else
+   if(markid && (this->flags() & regbase::save_subexpression_location))
+      this->m_pdata->m_subs.at(markid - 1).second = (m_position - m_base);
+#endif
+   ++m_position;
+   //
+   // append closing parenthesis state:
+   //
+   pb = static_cast<re_brace*>(this->append_state(syntax_element_endmark, sizeof(re_brace)));
+   pb->index = markid;
+   pb->icase = this->flags() & regbase::icase;
+   this->m_paren_start = last_paren_start;
+   //
+   // restore the alternate insertion point:
+   //
+   this->m_alt_insert_point = last_alt_point;
+   //
+   // allow backrefs to this mark:
+   //
+   if((markid > 0) && (markid < sizeof(unsigned) * CHAR_BIT))
+      this->m_backrefs |= 1u << (markid - 1);
+
+   return true;
+}
+
+template <class charT, class traits>
+bool basic_regex_parser<charT, traits>::parse_basic_escape()
+{
+   ++m_position;
+   bool result = true;
+   switch(this->m_traits.escape_syntax_type(*m_position))
+   {
+   case regex_constants::syntax_open_mark:
+      return parse_open_paren();
+   case regex_constants::syntax_close_mark:
+      return false;
+   case regex_constants::syntax_plus:
+      if(this->flags() & regex_constants::bk_plus_qm)
+      {
+         ++m_position;
+         return parse_repeat(1);
+      }
+      else
+         return parse_literal();
+   case regex_constants::syntax_question:
+      if(this->flags() & regex_constants::bk_plus_qm)
+      {
+         ++m_position;
+         return parse_repeat(0, 1);
+      }
+      else
+         return parse_literal();
+   case regex_constants::syntax_open_brace:
+      if(this->flags() & regbase::no_intervals)
+         return parse_literal();
+      ++m_position;
+      return parse_repeat_range(true);
+   case regex_constants::syntax_close_brace:
+      if(this->flags() & regbase::no_intervals)
+         return parse_literal();
+      fail(regex_constants::error_brace, this->m_position - this->m_base, "Found a closing repetition operator } with no corresponding {.");
+      return false;
+   case regex_constants::syntax_or:
+      if(this->flags() & regbase::bk_vbar)
+         return parse_alt();
+      else
+         result = parse_literal();
+      break;
+   case regex_constants::syntax_digit:
+      return parse_backref();
+   case regex_constants::escape_type_start_buffer:
+      if(this->flags() & regbase::emacs_ex)
+      {
+         ++m_position;
+         this->append_state(syntax_element_buffer_start);
+      }
+      else
+         result = parse_literal();
+      break;
+   case regex_constants::escape_type_end_buffer:
+      if(this->flags() & regbase::emacs_ex)
+      {
+         ++m_position;
+         this->append_state(syntax_element_buffer_end);
+      }
+      else
+         result = parse_literal();
+      break;
+   case regex_constants::escape_type_word_assert:
+      if(this->flags() & regbase::emacs_ex)
+      {
+         ++m_position;
+         this->append_state(syntax_element_word_boundary);
+      }
+      else
+         result = parse_literal();
+      break;
+   case regex_constants::escape_type_not_word_assert:
+      if(this->flags() & regbase::emacs_ex)
+      {
+         ++m_position;
+         this->append_state(syntax_element_within_word);
+      }
+      else
+         result = parse_literal();
+      break;
+   case regex_constants::escape_type_left_word:
+      if(this->flags() & regbase::emacs_ex)
+      {
+         ++m_position;
+         this->append_state(syntax_element_word_start);
+      }
+      else
+         result = parse_literal();
+      break;
+   case regex_constants::escape_type_right_word:
+      if(this->flags() & regbase::emacs_ex)
+      {
+         ++m_position;
+         this->append_state(syntax_element_word_end);
+      }
+      else
+         result = parse_literal();
+      break;
+   default:
+      if(this->flags() & regbase::emacs_ex)
+      {
+         bool negate = true;
+         switch(*m_position)
+         {
+         case 'w':
+            negate = false;
+            BOOST_FALLTHROUGH;
+         case 'W':
+            {
+            basic_char_set<charT, traits> char_set;
+            if(negate)
+               char_set.negate();
+            char_set.add_class(this->m_word_mask);
+            if(0 == this->append_set(char_set))
+            {
+               fail(regex_constants::error_ctype, m_position - m_base);
+               return false;
+            }
+            ++m_position;
+            return true;
+            }
+         case 's':
+            negate = false;
+            BOOST_FALLTHROUGH;
+         case 'S':
+            return add_emacs_code(negate);
+         case 'c':
+         case 'C':
+            // not supported yet:
+            fail(regex_constants::error_escape, m_position - m_base, "The \\c and \\C escape sequences are not supported by POSIX basic regular expressions: try the Perl syntax instead.");
+            return false;
+         default:
+            break;
+         }
+      }
+      result = parse_literal();
+      break;
+   }
+   return result;
+}
+
+template <class charT, class traits>
+bool basic_regex_parser<charT, traits>::parse_extended_escape()
+{
+   ++m_position;
+   if(m_position == m_end)
+   {
+      fail(regex_constants::error_escape, m_position - m_base, "Incomplete escape sequence found.");
+      return false;
+   }
+   bool negate = false; // in case this is a character class escape: \w \d etc
+   switch(this->m_traits.escape_syntax_type(*m_position))
+   {
+   case regex_constants::escape_type_not_class:
+      negate = true;
+      BOOST_FALLTHROUGH;
+   case regex_constants::escape_type_class:
+      {
+escape_type_class_jump:
+         typedef typename traits::char_class_type m_type;
+         m_type m = this->m_traits.lookup_classname(m_position, m_position+1);
+         if(m != 0)
+         {
+            basic_char_set<charT, traits> char_set;
+            if(negate)
+               char_set.negate();
+            char_set.add_class(m);
+            if(0 == this->append_set(char_set))
+            {
+               fail(regex_constants::error_ctype, m_position - m_base);
+               return false;
+            }
+            ++m_position;
+            return true;
+         }
+         //
+         // not a class, just a regular unknown escape:
+         //
+         this->append_literal(unescape_character());
+         break;
+      }
+   case regex_constants::syntax_digit:
+      return parse_backref();
+   case regex_constants::escape_type_left_word:
+      ++m_position;
+      this->append_state(syntax_element_word_start);
+      break;
+   case regex_constants::escape_type_right_word:
+      ++m_position;
+      this->append_state(syntax_element_word_end);
+      break;
+   case regex_constants::escape_type_start_buffer:
+      ++m_position;
+      this->append_state(syntax_element_buffer_start);
+      break;
+   case regex_constants::escape_type_end_buffer:
+      ++m_position;
+      this->append_state(syntax_element_buffer_end);
+      break;
+   case regex_constants::escape_type_word_assert:
+      ++m_position;
+      this->append_state(syntax_element_word_boundary);
+      break;
+   case regex_constants::escape_type_not_word_assert:
+      ++m_position;
+      this->append_state(syntax_element_within_word);
+      break;
+   case regex_constants::escape_type_Z:
+      ++m_position;
+      this->append_state(syntax_element_soft_buffer_end);
+      break;
+   case regex_constants::escape_type_Q:
+      return parse_QE();
+   case regex_constants::escape_type_C:
+      return parse_match_any();
+   case regex_constants::escape_type_X:
+      ++m_position;
+      this->append_state(syntax_element_combining);
+      break;
+   case regex_constants::escape_type_G:
+      ++m_position;
+      this->append_state(syntax_element_restart_continue);
+      break;
+   case regex_constants::escape_type_not_property:
+      negate = true;
+      BOOST_FALLTHROUGH;
+   case regex_constants::escape_type_property:
+      {
+         ++m_position;
+         char_class_type m;
+         if(m_position == m_end)
+         {
+            fail(regex_constants::error_escape, m_position - m_base, "Incomplete property escape found.");
+            return false;
+         }
+         // maybe have \p{ddd}
+         if(this->m_traits.syntax_type(*m_position) == regex_constants::syntax_open_brace)
+         {
+            const charT* base = m_position;
+            // skip forward until we find enclosing brace:
+            while((m_position != m_end) && (this->m_traits.syntax_type(*m_position) != regex_constants::syntax_close_brace))
+               ++m_position;
+            if(m_position == m_end)
+            {
+               fail(regex_constants::error_escape, m_position - m_base, "Closing } missing from property escape sequence.");
+               return false;
+            }
+            m = this->m_traits.lookup_classname(++base, m_position++);
+         }
+         else
+         {
+            m = this->m_traits.lookup_classname(m_position, m_position+1);
+            ++m_position;
+         }
+         if(m != 0)
+         {
+            basic_char_set<charT, traits> char_set;
+            if(negate)
+               char_set.negate();
+            char_set.add_class(m);
+            if(0 == this->append_set(char_set))
+            {
+               fail(regex_constants::error_ctype, m_position - m_base);
+               return false;
+            }
+            return true;
+         }
+         fail(regex_constants::error_ctype, m_position - m_base, "Escape sequence was neither a valid property nor a valid character class name.");
+         return false;
+      }
+   case regex_constants::escape_type_reset_start_mark:
+      if(0 == (this->flags() & (regbase::main_option_type | regbase::no_perl_ex)))
+      {
+         re_brace* pb = static_cast<re_brace*>(this->append_state(syntax_element_startmark, sizeof(re_brace)));
+         pb->index = -5;
+         pb->icase = this->flags() & regbase::icase;
+         this->m_pdata->m_data.align();
+         ++m_position;
+         return true;
+      }
+      goto escape_type_class_jump;
+   case regex_constants::escape_type_line_ending:
+      if(0 == (this->flags() & (regbase::main_option_type | regbase::no_perl_ex)))
+      {
+         const charT* e = get_escape_R_string<charT>();
+         const charT* old_position = m_position;
+         const charT* old_end = m_end;
+         const charT* old_base = m_base;
+         m_position = e;
+         m_base = e;
+         m_end = e + traits::length(e);
+         bool r = parse_all();
+         m_position = ++old_position;
+         m_end = old_end;
+         m_base = old_base;
+         return r;
+      }
+      goto escape_type_class_jump;
+   case regex_constants::escape_type_extended_backref:
+      if(0 == (this->flags() & (regbase::main_option_type | regbase::no_perl_ex)))
+      {
+         bool have_brace = false;
+         bool negative = false;
+         static const char* incomplete_message = "Incomplete \\g escape found.";
+         if(++m_position == m_end)
+         {
+            fail(regex_constants::error_escape, m_position - m_base, incomplete_message);
+            return false;
+         }
+         // maybe have \g{ddd}
+         regex_constants::syntax_type syn = this->m_traits.syntax_type(*m_position);
+         regex_constants::syntax_type syn_end = 0;
+         if((syn == regex_constants::syntax_open_brace) 
+            || (syn == regex_constants::escape_type_left_word)
+            || (syn == regex_constants::escape_type_end_buffer))
+         {
+            if(++m_position == m_end)
+            {
+               fail(regex_constants::error_escape, m_position - m_base, incomplete_message);
+               return false;
+            }
+            have_brace = true;
+            switch(syn)
+            {
+            case regex_constants::syntax_open_brace:
+               syn_end = regex_constants::syntax_close_brace;
+               break;
+            case regex_constants::escape_type_left_word:
+               syn_end = regex_constants::escape_type_right_word;
+               break;
+            default:
+               syn_end = regex_constants::escape_type_end_buffer;
+               break;
+            }
+         }
+         negative = (*m_position == static_cast<charT>('-'));
+         if((negative) && (++m_position == m_end))
+         {
+            fail(regex_constants::error_escape, m_position - m_base, incomplete_message);
+            return false;
+         }
+         const charT* pc = m_position;
+         int i = this->m_traits.toi(pc, m_end, 10);
+         if((i < 0) && syn_end)
+         {
+            // Check for a named capture, get the leftmost one if there is more than one:
+            const charT* base = m_position;
+            while((m_position != m_end) && (this->m_traits.syntax_type(*m_position) != syn_end))
+            {
+               ++m_position;
+            }
+            i = hash_value_from_capture_name(base, m_position);
+            pc = m_position;
+         }
+         if(negative)
+            i = 1 + m_mark_count - i;
+         if(((i > 0) && (this->m_backrefs & (1u << (i-1)))) || ((i > 10000) && (this->m_pdata->get_id(i) > 0) && (this->m_backrefs & (1u << (this->m_pdata->get_id(i)-1)))))
+         {
+            m_position = pc;
+            re_brace* pb = static_cast<re_brace*>(this->append_state(syntax_element_backref, sizeof(re_brace)));
+            pb->index = i;
+            pb->icase = this->flags() & regbase::icase;
+         }
+         else
+         {
+            fail(regex_constants::error_backref, m_position - m_base);
+            return false;
+         }
+         m_position = pc;
+         if(have_brace)
+         {
+            if((m_position == m_end) || (this->m_traits.syntax_type(*m_position) != syn_end))
+            {
+               fail(regex_constants::error_escape, m_position - m_base, incomplete_message);
+               return false;
+            }
+            ++m_position;
+         }
+         return true;
+      }
+      goto escape_type_class_jump;
+   case regex_constants::escape_type_control_v:
+      if(0 == (this->flags() & (regbase::main_option_type | regbase::no_perl_ex)))
+         goto escape_type_class_jump;
+      BOOST_FALLTHROUGH;
+   default:
+      this->append_literal(unescape_character());
+      break;
+   }
+   return true;
+}
+
+template <class charT, class traits>
+bool basic_regex_parser<charT, traits>::parse_match_any()
+{
+   //
+   // we have a '.' that can match any character:
+   //
+   ++m_position;
+   static_cast<re_dot*>(
+      this->append_state(syntax_element_wild, sizeof(re_dot))
+      )->mask = static_cast<unsigned char>(this->flags() & regbase::no_mod_s 
+      ? re_detail::force_not_newline 
+         : this->flags() & regbase::mod_s ?
+            re_detail::force_newline : re_detail::dont_care);
+   return true;
+}
+
+template <class charT, class traits>
+bool basic_regex_parser<charT, traits>::parse_repeat(std::size_t low, std::size_t high)
+{
+   bool greedy = true;
+   bool pocessive = false;
+   std::size_t insert_point;
+   // 
+   // when we get to here we may have a non-greedy ? mark still to come:
+   //
+   if((m_position != m_end) 
+      && (
+            (0 == (this->flags() & (regbase::main_option_type | regbase::no_perl_ex)))
+            || ((regbase::basic_syntax_group|regbase::emacs_ex) == (this->flags() & (regbase::main_option_type | regbase::emacs_ex)))
+         )
+      )
+   {
+      // OK we have a perl or emacs regex, check for a '?':
+      if(this->m_traits.syntax_type(*m_position) == regex_constants::syntax_question)
+      {
+         greedy = false;
+         ++m_position;
+      }
+      // for perl regexes only check for pocessive ++ repeats.
+      if((m_position != m_end)
+         && (0 == (this->flags() & regbase::main_option_type)) 
+         && (this->m_traits.syntax_type(*m_position) == regex_constants::syntax_plus))
+      {
+         pocessive = true;
+         ++m_position;
+      }
+   }
+   if(0 == this->m_last_state)
+   {
+      fail(regex_constants::error_badrepeat, ::cutl_details_boost::re_detail::distance(m_base, m_position), "Nothing to repeat.");
+      return false;
+   }
+   if(this->m_last_state->type == syntax_element_endmark)
+   {
+      // insert a repeat before the '(' matching the last ')':
+      insert_point = this->m_paren_start;
+   }
+   else if((this->m_last_state->type == syntax_element_literal) && (static_cast<re_literal*>(this->m_last_state)->length > 1))
+   {
+      // the last state was a literal with more than one character, split it in two:
+      re_literal* lit = static_cast<re_literal*>(this->m_last_state);
+      charT c = (static_cast<charT*>(static_cast<void*>(lit+1)))[lit->length - 1];
+      --(lit->length);
+      // now append new state:
+      lit = static_cast<re_literal*>(this->append_state(syntax_element_literal, sizeof(re_literal) + sizeof(charT)));
+      lit->length = 1;
+      (static_cast<charT*>(static_cast<void*>(lit+1)))[0] = c;
+      insert_point = this->getoffset(this->m_last_state);
+   }
+   else
+   {
+      // repeat the last state whatever it was, need to add some error checking here:
+      switch(this->m_last_state->type)
+      {
+      case syntax_element_start_line:
+      case syntax_element_end_line:
+      case syntax_element_word_boundary:
+      case syntax_element_within_word:
+      case syntax_element_word_start:
+      case syntax_element_word_end:
+      case syntax_element_buffer_start:
+      case syntax_element_buffer_end:
+      case syntax_element_alt:
+      case syntax_element_soft_buffer_end:
+      case syntax_element_restart_continue:
+      case syntax_element_jump:
+      case syntax_element_startmark:
+      case syntax_element_backstep:
+         // can't legally repeat any of the above:
+         fail(regex_constants::error_badrepeat, m_position - m_base);
+         return false;
+      default:
+         // do nothing...
+         break;
+      }
+      insert_point = this->getoffset(this->m_last_state);
+   }
+   //
+   // OK we now know what to repeat, so insert the repeat around it:
+   //
+   re_repeat* rep = static_cast<re_repeat*>(this->insert_state(insert_point, syntax_element_rep, re_repeater_size));
+   rep->min = low;
+   rep->max = high;
+   rep->greedy = greedy;
+   rep->leading = false;
+   // store our repeater position for later:
+   std::ptrdiff_t rep_off = this->getoffset(rep);
+   // and append a back jump to the repeat:
+   re_jump* jmp = static_cast<re_jump*>(this->append_state(syntax_element_jump, sizeof(re_jump)));
+   jmp->alt.i = rep_off - this->getoffset(jmp);
+   this->m_pdata->m_data.align();
+   // now fill in the alt jump for the repeat:
+   rep = static_cast<re_repeat*>(this->getaddress(rep_off));
+   rep->alt.i = this->m_pdata->m_data.size() - rep_off;
+   //
+   // If the repeat is pocessive then bracket the repeat with a (?>...)
+   // independent sub-expression construct:
+   //
+   if(pocessive)
+   {
+      if(m_position != m_end)
+      {
+         //
+         // Check for illegal following quantifier, we have to do this here, because
+         // the extra states we insert below circumvents our usual error checking :-(
+         //
+         switch(this->m_traits.syntax_type(*m_position))
+         {
+         case regex_constants::syntax_star:
+         case regex_constants::syntax_plus:
+         case regex_constants::syntax_question:
+         case regex_constants::syntax_open_brace:
+            fail(regex_constants::error_badrepeat, m_position - m_base);
+            return false;
+         }
+      }
+      re_brace* pb = static_cast<re_brace*>(this->insert_state(insert_point, syntax_element_startmark, sizeof(re_brace)));
+      pb->index = -3;
+      pb->icase = this->flags() & regbase::icase;
+      jmp = static_cast<re_jump*>(this->insert_state(insert_point + sizeof(re_brace), syntax_element_jump, sizeof(re_jump)));
+      this->m_pdata->m_data.align();
+      jmp->alt.i = this->m_pdata->m_data.size() - this->getoffset(jmp);
+      pb = static_cast<re_brace*>(this->append_state(syntax_element_endmark, sizeof(re_brace)));
+      pb->index = -3;
+      pb->icase = this->flags() & regbase::icase;
+   }
+   return true;
+}
+
+template <class charT, class traits>
+bool basic_regex_parser<charT, traits>::parse_repeat_range(bool isbasic)
+{
+   static const char* incomplete_message = "Missing } in quantified repetition.";
+   //
+   // parse a repeat-range:
+   //
+   std::size_t min, max;
+   int v;
+   // skip whitespace:
+   while((m_position != m_end) && this->m_traits.isctype(*m_position, this->m_mask_space))
+      ++m_position;
+   if(this->m_position == this->m_end)
+   {
+      if(this->flags() & (regbase::main_option_type | regbase::no_perl_ex))
+      {
+         fail(regex_constants::error_brace, this->m_position - this->m_base, incomplete_message);
+         return false;
+      }
+      // Treat the opening '{' as a literal character, rewind to start of error:
+      --m_position;
+      while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_brace) --m_position;
+      return parse_literal();
+   }
+   // get min:
+   v = this->m_traits.toi(m_position, m_end, 10);
+   // skip whitespace:
+   if(v < 0)
+   {
+      if(this->flags() & (regbase::main_option_type | regbase::no_perl_ex))
+      {
+         fail(regex_constants::error_brace, this->m_position - this->m_base, incomplete_message);
+         return false;
+      }
+      // Treat the opening '{' as a literal character, rewind to start of error:
+      --m_position;
+      while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_brace) --m_position;
+      return parse_literal();
+   }
+   while((m_position != m_end) && this->m_traits.isctype(*m_position, this->m_mask_space))
+      ++m_position;
+   if(this->m_position == this->m_end)
+   {
+      if(this->flags() & (regbase::main_option_type | regbase::no_perl_ex))
+      {
+         fail(regex_constants::error_brace, this->m_position - this->m_base, incomplete_message);
+         return false;
+      }
+      // Treat the opening '{' as a literal character, rewind to start of error:
+      --m_position;
+      while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_brace) --m_position;
+      return parse_literal();
+   }
+   min = v;
+   // see if we have a comma:
+   if(this->m_traits.syntax_type(*m_position) == regex_constants::syntax_comma)
+   {
+      // move on and error check:
+      ++m_position;
+      // skip whitespace:
+      while((m_position != m_end) && this->m_traits.isctype(*m_position, this->m_mask_space))
+         ++m_position;
+      if(this->m_position == this->m_end)
+      {
+         if(this->flags() & (regbase::main_option_type | regbase::no_perl_ex))
+         {
+            fail(regex_constants::error_brace, this->m_position - this->m_base, incomplete_message);
+            return false;
+         }
+         // Treat the opening '{' as a literal character, rewind to start of error:
+         --m_position;
+         while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_brace) --m_position;
+         return parse_literal();
+      }
+      // get the value if any:
+      v = this->m_traits.toi(m_position, m_end, 10);
+      max = (v >= 0) ? (std::size_t)v : (std::numeric_limits<std::size_t>::max)();
+   }
+   else
+   {
+      // no comma, max = min:
+      max = min;
+   }
+   // skip whitespace:
+   while((m_position != m_end) && this->m_traits.isctype(*m_position, this->m_mask_space))
+      ++m_position;
+   // OK now check trailing }:
+   if(this->m_position == this->m_end)
+   {
+      if(this->flags() & (regbase::main_option_type | regbase::no_perl_ex))
+      {
+         fail(regex_constants::error_brace, this->m_position - this->m_base, incomplete_message);
+         return false;
+      }
+      // Treat the opening '{' as a literal character, rewind to start of error:
+      --m_position;
+      while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_brace) --m_position;
+      return parse_literal();
+   }
+   if(isbasic)
+   {
+      if(this->m_traits.syntax_type(*m_position) == regex_constants::syntax_escape)
+      {
+         ++m_position;
+         if(this->m_position == this->m_end)
+         {
+            fail(regex_constants::error_brace, this->m_position - this->m_base, incomplete_message);
+            return false;
+         }
+      }
+      else
+      {
+         fail(regex_constants::error_brace, this->m_position - this->m_base, incomplete_message);
+         return false;
+      }
+   }
+   if(this->m_traits.syntax_type(*m_position) == regex_constants::syntax_close_brace)
+      ++m_position;
+   else
+   {
+      // Treat the opening '{' as a literal character, rewind to start of error:
+      --m_position;
+      while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_brace) --m_position;
+      return parse_literal();
+   }
+   //
+   // finally go and add the repeat, unless error:
+   //
+   if(min > max)
+   {
+      // Backtrack to error location:
+      m_position -= 2;
+      while(this->m_traits.isctype(*m_position, this->m_word_mask)) --m_position;
+         ++m_position;
+      fail(regex_constants::error_badbrace, m_position - m_base);
+      return false;
+   }
+   return parse_repeat(min, max);
+}
+
+template <class charT, class traits>
+bool basic_regex_parser<charT, traits>::parse_alt()
+{
+   //
+   // error check: if there have been no previous states,
+   // or if the last state was a '(' then error:
+   //
+   if(
+      ((this->m_last_state == 0) || (this->m_last_state->type == syntax_element_startmark))
+      &&
+      !(
+         ((this->flags() & regbase::main_option_type) == regbase::perl_syntax_group)
+           &&
+         ((this->flags() & regbase::no_empty_expressions) == 0)
+        )
+      )
+   {
+      fail(regex_constants::error_empty, this->m_position - this->m_base, "A regular expression can start with the alternation operator |.");
+      return false;
+   }
+   //
+   // Reset mark count if required:
+   //
+   if(m_max_mark < m_mark_count)
+      m_max_mark = m_mark_count;
+   if(m_mark_reset >= 0)
+      m_mark_count = m_mark_reset;
+
+   ++m_position;
+   //
+   // we need to append a trailing jump: 
+   //
+   re_syntax_base* pj = this->append_state(re_detail::syntax_element_jump, sizeof(re_jump));
+   std::ptrdiff_t jump_offset = this->getoffset(pj);
+   //
+   // now insert the alternative:
+   //
+   re_alt* palt = static_cast<re_alt*>(this->insert_state(this->m_alt_insert_point, syntax_element_alt, re_alt_size));
+   jump_offset += re_alt_size;
+   this->m_pdata->m_data.align();
+   palt->alt.i = this->m_pdata->m_data.size() - this->getoffset(palt);
+   //
+   // update m_alt_insert_point so that the next alternate gets
+   // inserted at the start of the second of the two we've just created:
+   //
+   this->m_alt_insert_point = this->m_pdata->m_data.size();
+   //
+   // the start of this alternative must have a case changes state
+   // if the current block has messed around with case changes:
+   //
+   if(m_has_case_change)
+   {
+      static_cast<re_case*>(
+         this->append_state(syntax_element_toggle_case, sizeof(re_case))
+         )->icase = this->m_icase;
+   }
+   //
+   // push the alternative onto our stack, a recursive
+   // implementation here is easier to understand (and faster
+   // as it happens), but causes all kinds of stack overflow problems
+   // on programs with small stacks (COM+).
+   //
+   m_alt_jumps.push_back(jump_offset);
+   return true;
+}
+
+template <class charT, class traits>
+bool basic_regex_parser<charT, traits>::parse_set()
+{
+   static const char* incomplete_message = "Character set declaration starting with [ terminated prematurely - either no ] was found or the set had no content.";
+   ++m_position;
+   if(m_position == m_end)
+   {
+      fail(regex_constants::error_brack, m_position - m_base, incomplete_message);
+      return false;
+   }
+   basic_char_set<charT, traits> char_set;
+
+   const charT* base = m_position;  // where the '[' was
+   const charT* item_base = m_position;  // where the '[' or '^' was
+
+   while(m_position != m_end)
+   {
+      switch(this->m_traits.syntax_type(*m_position))
+      {
+      case regex_constants::syntax_caret:
+         if(m_position == base)
+         {
+            char_set.negate();
+            ++m_position;
+            item_base = m_position;
+         }
+         else
+            parse_set_literal(char_set);
+         break;
+      case regex_constants::syntax_close_set:
+         if(m_position == item_base)
+         {
+            parse_set_literal(char_set);
+            break;
+         }
+         else
+         {
+            ++m_position;
+            if(0 == this->append_set(char_set))
+            {
+               fail(regex_constants::error_ctype, m_position - m_base);
+               return false;
+            }
+         }
+         return true;
+      case regex_constants::syntax_open_set:
+         if(parse_inner_set(char_set))
+            break;
+         return true;
+      case regex_constants::syntax_escape:
+         {
+            // 
+            // look ahead and see if this is a character class shortcut
+            // \d \w \s etc...
+            //
+            ++m_position;
+            if(this->m_traits.escape_syntax_type(*m_position)
+               == regex_constants::escape_type_class)
+            {
+               char_class_type m = this->m_traits.lookup_classname(m_position, m_position+1);
+               if(m != 0)
+               {
+                  char_set.add_class(m);
+                  ++m_position;
+                  break;
+               }
+            }
+            else if(this->m_traits.escape_syntax_type(*m_position)
+               == regex_constants::escape_type_not_class)
+            {
+               // negated character class:
+               char_class_type m = this->m_traits.lookup_classname(m_position, m_position+1);
+               if(m != 0)
+               {
+                  char_set.add_negated_class(m);
+                  ++m_position;
+                  break;
+               }
+            }
+            // not a character class, just a regular escape:
+            --m_position;
+            parse_set_literal(char_set);
+            break;
+         }
+      default:
+         parse_set_literal(char_set);
+         break;
+      }
+   }
+   return m_position != m_end;
+}
+
+template <class charT, class traits>
+bool basic_regex_parser<charT, traits>::parse_inner_set(basic_char_set<charT, traits>& char_set)
+{
+   static const char* incomplete_message = "Character class declaration starting with [ terminated prematurely - either no ] was found or the set had no content.";
+   //
+   // we have either a character class [:name:]
+   // a collating element [.name.]
+   // or an equivalence class [=name=]
+   //
+   if(m_end == ++m_position)
+   {
+      fail(regex_constants::error_brack, m_position - m_base, incomplete_message);
+      return false;
+   }
+   switch(this->m_traits.syntax_type(*m_position))
+   {
+   case regex_constants::syntax_dot:
+      //
+      // a collating element is treated as a literal:
+      //
+      --m_position;
+      parse_set_literal(char_set);
+      return true;
+   case regex_constants::syntax_colon:
+      {
+      // check that character classes are actually enabled:
+      if((this->flags() & (regbase::main_option_type | regbase::no_char_classes)) 
+         == (regbase::basic_syntax_group  | regbase::no_char_classes))
+      {
+         --m_position;
+         parse_set_literal(char_set);
+         return true;
+      }
+      // skip the ':'
+      if(m_end == ++m_position)
+      {
+         fail(regex_constants::error_brack, m_position - m_base, incomplete_message);
+         return false;
+      }
+      const charT* name_first = m_position;
+      // skip at least one character, then find the matching ':]'
+      if(m_end == ++m_position)
+      {
+         fail(regex_constants::error_brack, m_position - m_base, incomplete_message);
+         return false;
+      }
+      while((m_position != m_end) 
+         && (this->m_traits.syntax_type(*m_position) != regex_constants::syntax_colon)) 
+         ++m_position;
+      const charT* name_last = m_position;
+      if(m_end == m_position)
+      {
+         fail(regex_constants::error_brack, m_position - m_base, incomplete_message);
+         return false;
+      }
+      if((m_end == ++m_position) 
+         || (this->m_traits.syntax_type(*m_position) != regex_constants::syntax_close_set))
+      {
+         fail(regex_constants::error_brack, m_position - m_base, incomplete_message);
+         return false;
+      }
+      //
+      // check for negated class:
+      //
+      bool negated = false;
+      if(this->m_traits.syntax_type(*name_first) == regex_constants::syntax_caret)
+      {
+         ++name_first;
+         negated = true;
+      }
+      typedef typename traits::char_class_type m_type;
+      m_type m = this->m_traits.lookup_classname(name_first, name_last);
+      if(m == 0)
+      {
+         if(char_set.empty() && (name_last - name_first == 1))
+         {
+            // maybe a special case:
+            ++m_position;
+            if( (m_position != m_end) 
+               && (this->m_traits.syntax_type(*m_position) 
+                  == regex_constants::syntax_close_set))
+            {
+               if(this->m_traits.escape_syntax_type(*name_first) 
+                  == regex_constants::escape_type_left_word)
+               {
+                  ++m_position;
+                  this->append_state(syntax_element_word_start);
+                  return false;
+               }
+               if(this->m_traits.escape_syntax_type(*name_first) 
+                  == regex_constants::escape_type_right_word)
+               {
+                  ++m_position;
+                  this->append_state(syntax_element_word_end);
+                  return false;
+               }
+            }
+         }
+         fail(regex_constants::error_ctype, name_first - m_base);
+         return false;
+      }
+      if(negated == false)
+         char_set.add_class(m);
+      else
+         char_set.add_negated_class(m);
+      ++m_position;
+      break;
+   }
+   case regex_constants::syntax_equal:
+      {
+      // skip the '='
+      if(m_end == ++m_position)
+      {
+         fail(regex_constants::error_brack, m_position - m_base, incomplete_message);
+         return false;
+      }
+      const charT* name_first = m_position;
+      // skip at least one character, then find the matching '=]'
+      if(m_end == ++m_position)
+      {
+         fail(regex_constants::error_brack, m_position - m_base, incomplete_message);
+         return false;
+      }
+      while((m_position != m_end) 
+         && (this->m_traits.syntax_type(*m_position) != regex_constants::syntax_equal)) 
+         ++m_position;
+      const charT* name_last = m_position;
+      if(m_end == m_position)
+      {
+         fail(regex_constants::error_brack, m_position - m_base, incomplete_message);
+         return false;
+      }
+      if((m_end == ++m_position) 
+         || (this->m_traits.syntax_type(*m_position) != regex_constants::syntax_close_set))
+      {
+         fail(regex_constants::error_brack, m_position - m_base, incomplete_message);
+         return false;
+      }
+      string_type m = this->m_traits.lookup_collatename(name_first, name_last);
+      if((0 == m.size()) || (m.size() > 2))
+      {
+         fail(regex_constants::error_collate, name_first - m_base);
+         return false;
+      }
+      digraph<charT> d;
+      d.first = m[0];
+      if(m.size() > 1)
+         d.second = m[1];
+      else
+         d.second = 0;
+      char_set.add_equivalent(d);
+      ++m_position;
+      break;
+   }
+   default:
+      --m_position;
+      parse_set_literal(char_set);
+      break;
+   }
+   return true;
+}
+
+template <class charT, class traits>
+void basic_regex_parser<charT, traits>::parse_set_literal(basic_char_set<charT, traits>& char_set)
+{
+   digraph<charT> start_range(get_next_set_literal(char_set));
+   if(m_end == m_position)
+   {
+      fail(regex_constants::error_brack, m_position - m_base);
+      return;
+   }
+   if(this->m_traits.syntax_type(*m_position) == regex_constants::syntax_dash)
+   {
+      // we have a range:
+      if(m_end == ++m_position)
+      {
+         fail(regex_constants::error_brack, m_position - m_base);
+         return;
+      }
+      if(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_close_set)
+      {
+         digraph<charT> end_range = get_next_set_literal(char_set);
+         char_set.add_range(start_range, end_range);
+         if(this->m_traits.syntax_type(*m_position) == regex_constants::syntax_dash)
+         {
+            if(m_end == ++m_position)
+            {
+               fail(regex_constants::error_brack, m_position - m_base);
+               return;
+            }
+            if(this->m_traits.syntax_type(*m_position) == regex_constants::syntax_close_set)
+            {
+               // trailing - :
+               --m_position;
+               return;
+            }
+            fail(regex_constants::error_range, m_position - m_base);
+            return;
+         }
+         return;
+      }
+      --m_position;
+   }
+   char_set.add_single(start_range);
+}
+
+template <class charT, class traits>
+digraph<charT> basic_regex_parser<charT, traits>::get_next_set_literal(basic_char_set<charT, traits>& char_set)
+{
+   digraph<charT> result;
+   switch(this->m_traits.syntax_type(*m_position))
+   {
+   case regex_constants::syntax_dash:
+      if(!char_set.empty())
+      {
+         // see if we are at the end of the set:
+         if((++m_position == m_end) || (this->m_traits.syntax_type(*m_position) != regex_constants::syntax_close_set))
+         {
+            fail(regex_constants::error_range, m_position - m_base);
+            return result;
+         }
+         --m_position;
+      }
+      result.first = *m_position++;
+      return result;
+   case regex_constants::syntax_escape:
+      // check to see if escapes are supported first:
+      if(this->flags() & regex_constants::no_escape_in_lists)
+      {
+         result = *m_position++;
+         break;
+      }
+      ++m_position;
+      result = unescape_character();
+      break;
+   case regex_constants::syntax_open_set:
+   {
+      if(m_end == ++m_position)
+      {
+         fail(regex_constants::error_collate, m_position - m_base);
+         return result;
+      }
+      if(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_dot)
+      {
+         --m_position;
+         result.first = *m_position;
+         ++m_position;
+         return result;
+      }
+      if(m_end == ++m_position)
+      {
+         fail(regex_constants::error_collate, m_position - m_base);
+         return result;
+      }
+      const charT* name_first = m_position;
+      // skip at least one character, then find the matching ':]'
+      if(m_end == ++m_position)
+      {
+         fail(regex_constants::error_collate, name_first - m_base);
+         return result;
+      }
+      while((m_position != m_end) 
+         && (this->m_traits.syntax_type(*m_position) != regex_constants::syntax_dot)) 
+         ++m_position;
+      const charT* name_last = m_position;
+      if(m_end == m_position)
+      {
+         fail(regex_constants::error_collate, name_first - m_base);
+         return result;
+      }
+      if((m_end == ++m_position) 
+         || (this->m_traits.syntax_type(*m_position) != regex_constants::syntax_close_set))
+      {
+         fail(regex_constants::error_collate, name_first - m_base);
+         return result;
+      }
+      ++m_position;
+      string_type s = this->m_traits.lookup_collatename(name_first, name_last);
+      if(s.empty() || (s.size() > 2))
+      {
+         fail(regex_constants::error_collate, name_first - m_base);
+         return result;
+      }
+      result.first = s[0];
+      if(s.size() > 1)
+         result.second = s[1];
+      else
+         result.second = 0;
+      return result;
+   }
+   default:
+      result = *m_position++;
+   }
+   return result;
+}
+
+//
+// does a value fit in the specified charT type?
+//
+template <class charT>
+bool valid_value(charT, int v, const mpl::true_&)
+{
+   return (v >> (sizeof(charT) * CHAR_BIT)) == 0;
+}
+template <class charT>
+bool valid_value(charT, int, const mpl::false_&)
+{
+   return true; // v will alsways fit in a charT
+}
+template <class charT>
+bool valid_value(charT c, int v)
+{
+   return valid_value(c, v, mpl::bool_<(sizeof(charT) < sizeof(int))>());
+}
+
+template <class charT, class traits>
+charT basic_regex_parser<charT, traits>::unescape_character()
+{
+#ifdef BOOST_MSVC
+#pragma warning(push)
+#pragma warning(disable:4127)
+#endif
+   charT result(0);
+   if(m_position == m_end)
+   {
+      fail(regex_constants::error_escape, m_position - m_base, "Escape sequence terminated prematurely.");
+      return false;
+   }
+   switch(this->m_traits.escape_syntax_type(*m_position))
+   {
+   case regex_constants::escape_type_control_a:
+      result = charT('\a');
+      break;
+   case regex_constants::escape_type_e:
+      result = charT(27);
+      break;
+   case regex_constants::escape_type_control_f:
+      result = charT('\f');
+      break;
+   case regex_constants::escape_type_control_n:
+      result = charT('\n');
+      break;
+   case regex_constants::escape_type_control_r:
+      result = charT('\r');
+      break;
+   case regex_constants::escape_type_control_t:
+      result = charT('\t');
+      break;
+   case regex_constants::escape_type_control_v:
+      result = charT('\v');
+      break;
+   case regex_constants::escape_type_word_assert:
+      result = charT('\b');
+      break;
+   case regex_constants::escape_type_ascii_control:
+      ++m_position;
+      if(m_position == m_end)
+      {
+         // Rewind to start of escape:
+         --m_position;
+         while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_escape) --m_position;
+         fail(regex_constants::error_escape, m_position - m_base, "ASCII escape sequence terminated prematurely.");
+         return result;
+      }
+      result = static_cast<charT>(*m_position % 32);
+      break;
+   case regex_constants::escape_type_hex:
+      ++m_position;
+      if(m_position == m_end)
+      {
+         // Rewind to start of escape:
+         --m_position;
+         while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_escape) --m_position;
+         fail(regex_constants::error_escape, m_position - m_base, "Hexadecimal escape sequence terminated prematurely.");
+         return result;
+      }
+      // maybe have \x{ddd}
+      if(this->m_traits.syntax_type(*m_position) == regex_constants::syntax_open_brace)
+      {
+         ++m_position;
+         if(m_position == m_end)
+         {
+            // Rewind to start of escape:
+            --m_position;
+            while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_escape) --m_position;
+            fail(regex_constants::error_escape, m_position - m_base, "Missing } in hexadecimal escape sequence.");
+            return result;
+         }
+         int i = this->m_traits.toi(m_position, m_end, 16);
+         if((m_position == m_end)
+            || (i < 0)
+            || ((std::numeric_limits<charT>::is_specialized) && (i > (int)(std::numeric_limits<charT>::max)()))
+            || (this->m_traits.syntax_type(*m_position) != regex_constants::syntax_close_brace))
+         {
+            // Rewind to start of escape:
+            --m_position;
+            while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_escape) --m_position;
+            fail(regex_constants::error_badbrace, m_position - m_base, "Hexadecimal escape sequence was invalid.");
+            return result;
+         }
+         ++m_position;
+         result = charT(i);
+      }
+      else
+      {
+         std::ptrdiff_t len = (std::min)(static_cast<std::ptrdiff_t>(2), static_cast<std::ptrdiff_t>(m_end - m_position));
+         int i = this->m_traits.toi(m_position, m_position + len, 16);
+         if((i < 0)
+            || !valid_value(charT(0), i))
+         {
+            // Rewind to start of escape:
+            --m_position;
+            while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_escape) --m_position;
+            fail(regex_constants::error_escape, m_position - m_base, "Escape sequence did not encode a valid character.");
+            return result;
+         }
+         result = charT(i);
+      }
+      return result;
+   case regex_constants::syntax_digit:
+      {
+      // an octal escape sequence, the first character must be a zero
+      // followed by up to 3 octal digits:
+      std::ptrdiff_t len = (std::min)(::cutl_details_boost::re_detail::distance(m_position, m_end), static_cast<std::ptrdiff_t>(4));
+      const charT* bp = m_position;
+      int val = this->m_traits.toi(bp, bp + 1, 8);
+      if(val != 0)
+      {
+         // Rewind to start of escape:
+         --m_position;
+         while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_escape) --m_position;
+         // Oops not an octal escape after all:
+         fail(regex_constants::error_escape, m_position - m_base, "Invalid octal escape sequence.");
+         return result;
+      }
+      val = this->m_traits.toi(m_position, m_position + len, 8);
+      if(val < 0) 
+      {
+         // Rewind to start of escape:
+         --m_position;
+         while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_escape) --m_position;
+         fail(regex_constants::error_escape, m_position - m_base, "Octal escape sequence is invalid.");
+         return result;
+      }
+      return static_cast<charT>(val);
+      }
+   case regex_constants::escape_type_named_char:
+      {
+         ++m_position;
+         if(m_position == m_end)
+         {
+            // Rewind to start of escape:
+            --m_position;
+            while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_escape) --m_position;
+            fail(regex_constants::error_escape, m_position - m_base);
+            return false;
+         }
+         // maybe have \N{name}
+         if(this->m_traits.syntax_type(*m_position) == regex_constants::syntax_open_brace)
+         {
+            const charT* base = m_position;
+            // skip forward until we find enclosing brace:
+            while((m_position != m_end) && (this->m_traits.syntax_type(*m_position) != regex_constants::syntax_close_brace))
+               ++m_position;
+            if(m_position == m_end)
+            {
+               // Rewind to start of escape:
+               --m_position;
+               while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_escape) --m_position;
+               fail(regex_constants::error_escape, m_position - m_base);
+               return false;
+            }
+            string_type s = this->m_traits.lookup_collatename(++base, m_position++);
+            if(s.empty())
+            {
+               // Rewind to start of escape:
+               --m_position;
+               while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_escape) --m_position;
+               fail(regex_constants::error_collate, m_position - m_base);
+               return false;
+            }
+            if(s.size() == 1)
+            {
+               return s[0];
+            }
+         }
+         // fall through is a failure:
+         // Rewind to start of escape:
+         --m_position;
+         while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_escape) --m_position;
+         fail(regex_constants::error_escape, m_position - m_base);
+         return false;
+      }
+   default:
+      result = *m_position;
+      break;
+   }
+   ++m_position;
+   return result;
+#ifdef BOOST_MSVC
+#pragma warning(pop)
+#endif
+}
+
+template <class charT, class traits>
+bool basic_regex_parser<charT, traits>::parse_backref()
+{
+   BOOST_ASSERT(m_position != m_end);
+   const charT* pc = m_position;
+   int i = this->m_traits.toi(pc, pc + 1, 10);
+   if((i == 0) || (((this->flags() & regbase::main_option_type) == regbase::perl_syntax_group) && (this->flags() & regbase::no_bk_refs)))
+   {
+      // not a backref at all but an octal escape sequence:
+      charT c = unescape_character();
+      this->append_literal(c);
+   }
+   else if((i > 0) && (this->m_backrefs & (1u << (i-1))))
+   {
+      m_position = pc;
+      re_brace* pb = static_cast<re_brace*>(this->append_state(syntax_element_backref, sizeof(re_brace)));
+      pb->index = i;
+      pb->icase = this->flags() & regbase::icase;
+   }
+   else
+   {
+      // Rewind to start of escape:
+      --m_position;
+      while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_escape) --m_position;
+      fail(regex_constants::error_backref, m_position - m_base);
+      return false;
+   }
+   return true;
+}
+
+template <class charT, class traits>
+bool basic_regex_parser<charT, traits>::parse_QE()
+{
+#ifdef BOOST_MSVC
+#pragma warning(push)
+#pragma warning(disable:4127)
+#endif
+   //
+   // parse a \Q...\E sequence:
+   //
+   ++m_position; // skip the Q
+   const charT* start = m_position;
+   const charT* end;
+   do
+   {
+      while((m_position != m_end) 
+         && (this->m_traits.syntax_type(*m_position) != regex_constants::syntax_escape))
+         ++m_position;
+      if(m_position == m_end)
+      {
+         //  a \Q...\E sequence may terminate with the end of the expression:
+         end = m_position;
+         break;  
+      }
+      if(++m_position == m_end) // skip the escape
+      {
+         fail(regex_constants::error_escape, m_position - m_base, "Unterminated \\Q...\\E sequence.");
+         return false;
+      }
+      // check to see if it's a \E:
+      if(this->m_traits.escape_syntax_type(*m_position) == regex_constants::escape_type_E)
+      {
+         ++m_position;
+         end = m_position - 2;
+         break;
+      }
+      // otherwise go round again:
+   }while(true);
+   //
+   // now add all the character between the two escapes as literals:
+   //
+   while(start != end)
+   {
+      this->append_literal(*start);
+      ++start;
+   }
+   return true;
+#ifdef BOOST_MSVC
+#pragma warning(pop)
+#endif
+}
+
+template <class charT, class traits>
+bool basic_regex_parser<charT, traits>::parse_perl_extension()
+{
+   if(++m_position == m_end)
+   {
+      // Rewind to start of (? sequence:
+      --m_position;
+      while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+      fail(regex_constants::error_perl_extension, m_position - m_base);
+      return false;
+   }
+   //
+   // treat comments as a special case, as these
+   // are the only ones that don't start with a leading
+   // startmark state:
+   //
+   if(this->m_traits.syntax_type(*m_position) == regex_constants::syntax_hash)
+   {
+      while((m_position != m_end) 
+         && (this->m_traits.syntax_type(*m_position++) != regex_constants::syntax_close_mark))
+      {}      
+      return true;
+   }
+   //
+   // backup some state, and prepare the way:
+   //
+   int markid = 0;
+   std::ptrdiff_t jump_offset = 0;
+   re_brace* pb = static_cast<re_brace*>(this->append_state(syntax_element_startmark, sizeof(re_brace)));
+   pb->icase = this->flags() & regbase::icase;
+   std::ptrdiff_t last_paren_start = this->getoffset(pb);
+   // back up insertion point for alternations, and set new point:
+   std::ptrdiff_t last_alt_point = m_alt_insert_point;
+   this->m_pdata->m_data.align();
+   m_alt_insert_point = this->m_pdata->m_data.size();
+   std::ptrdiff_t expected_alt_point = m_alt_insert_point;
+   bool restore_flags = true;
+   regex_constants::syntax_option_type old_flags = this->flags();
+   bool old_case_change = m_has_case_change;
+   m_has_case_change = false;
+   charT name_delim;
+   int mark_reset = m_mark_reset;
+   int max_mark = m_max_mark;
+   m_mark_reset = -1;
+   m_max_mark = m_mark_count;
+   int v;
+   //
+   // select the actual extension used:
+   //
+   switch(this->m_traits.syntax_type(*m_position))
+   {
+   case regex_constants::syntax_or:
+      m_mark_reset = m_mark_count;
+      BOOST_FALLTHROUGH;
+   case regex_constants::syntax_colon:
+      //
+      // a non-capturing mark:
+      //
+      pb->index = markid = 0;
+      ++m_position;
+      break;
+   case regex_constants::syntax_digit:
+      {
+      //
+      // a recursive subexpression:
+      //
+      v = this->m_traits.toi(m_position, m_end, 10);
+      if((v < 0) || (this->m_traits.syntax_type(*m_position) != regex_constants::syntax_close_mark))
+      {
+         // Rewind to start of (? sequence:
+         --m_position;
+         while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+         fail(regex_constants::error_perl_extension, m_position - m_base, "The recursive sub-expression refers to an invalid marking group, or is unterminated.");
+         return false;
+      }
+insert_recursion:
+      pb->index = markid = 0;
+      re_recurse* pr = static_cast<re_recurse*>(this->append_state(syntax_element_recurse, sizeof(re_recurse)));
+      pr->alt.i = v;
+      pr->state_id = 0;
+      static_cast<re_case*>(
+            this->append_state(syntax_element_toggle_case, sizeof(re_case))
+            )->icase = this->flags() & regbase::icase;
+      break;
+      }
+   case regex_constants::syntax_plus:
+      //
+      // A forward-relative recursive subexpression:
+      //
+      ++m_position;
+      v = this->m_traits.toi(m_position, m_end, 10);
+      if((v <= 0) || (this->m_traits.syntax_type(*m_position) != regex_constants::syntax_close_mark))
+      {
+         // Rewind to start of (? sequence:
+         --m_position;
+         while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+         fail(regex_constants::error_perl_extension, m_position - m_base, "An invalid or unterminated recursive sub-expression.");
+         return false;
+      }
+      v += m_mark_count;
+      goto insert_recursion;
+   case regex_constants::syntax_dash:
+      //
+      // Possibly a backward-relative recursive subexpression:
+      //
+      ++m_position;
+      v = this->m_traits.toi(m_position, m_end, 10);
+      if(v <= 0)
+      {
+         --m_position;
+         // Oops not a relative recursion at all, but a (?-imsx) group:
+         goto option_group_jump;
+      }
+      v = m_mark_count + 1 - v;
+      if(v <= 0)
+      {
+         // Rewind to start of (? sequence:
+         --m_position;
+         while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+         fail(regex_constants::error_perl_extension, m_position - m_base, "An invalid or unterminated recursive sub-expression.");
+         return false;
+      }
+      goto insert_recursion;
+   case regex_constants::syntax_equal:
+      pb->index = markid = -1;
+      ++m_position;
+      jump_offset = this->getoffset(this->append_state(syntax_element_jump, sizeof(re_jump)));
+      this->m_pdata->m_data.align();
+      m_alt_insert_point = this->m_pdata->m_data.size();
+      break;
+   case regex_constants::syntax_not:
+      pb->index = markid = -2;
+      ++m_position;
+      jump_offset = this->getoffset(this->append_state(syntax_element_jump, sizeof(re_jump)));
+      this->m_pdata->m_data.align();
+      m_alt_insert_point = this->m_pdata->m_data.size();
+      break;
+   case regex_constants::escape_type_left_word:
+      {
+         // a lookbehind assertion:
+         if(++m_position == m_end)
+         {
+            // Rewind to start of (? sequence:
+            --m_position;
+            while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+            fail(regex_constants::error_perl_extension, m_position - m_base);
+            return false;
+         }
+         regex_constants::syntax_type t = this->m_traits.syntax_type(*m_position);
+         if(t == regex_constants::syntax_not)
+            pb->index = markid = -2;
+         else if(t == regex_constants::syntax_equal)
+            pb->index = markid = -1;
+         else
+         {
+            // Probably a named capture which also starts (?< :
+            name_delim = '>';
+            --m_position;
+            goto named_capture_jump;
+         }
+         ++m_position;
+         jump_offset = this->getoffset(this->append_state(syntax_element_jump, sizeof(re_jump)));
+         this->append_state(syntax_element_backstep, sizeof(re_brace));
+         this->m_pdata->m_data.align();
+         m_alt_insert_point = this->m_pdata->m_data.size();
+         break;
+      }
+   case regex_constants::escape_type_right_word:
+      //
+      // an independent sub-expression:
+      //
+      pb->index = markid = -3;
+      ++m_position;
+      jump_offset = this->getoffset(this->append_state(syntax_element_jump, sizeof(re_jump)));
+      this->m_pdata->m_data.align();
+      m_alt_insert_point = this->m_pdata->m_data.size();
+      break;
+   case regex_constants::syntax_open_mark:
+      {
+      // a conditional expression:
+      pb->index = markid = -4;
+      if(++m_position == m_end)
+      {
+         // Rewind to start of (? sequence:
+         --m_position;
+         while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+         fail(regex_constants::error_perl_extension, m_position - m_base);
+         return false;
+      }
+      v = this->m_traits.toi(m_position, m_end, 10);
+      if(m_position == m_end)
+      {
+         // Rewind to start of (? sequence:
+         --m_position;
+         while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+         fail(regex_constants::error_perl_extension, m_position - m_base);
+         return false;
+      }
+      if(*m_position == charT('R'))
+      {
+         if(++m_position == m_end)
+         {
+            // Rewind to start of (? sequence:
+            --m_position;
+            while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+            fail(regex_constants::error_perl_extension, m_position - m_base);
+            return false;
+         }
+         if(*m_position == charT('&'))
+         {
+            const charT* base = ++m_position;
+            while((m_position != m_end) && (this->m_traits.syntax_type(*m_position) != regex_constants::syntax_close_mark))
+               ++m_position;
+            if(m_position == m_end)
+            {
+               // Rewind to start of (? sequence:
+               --m_position;
+               while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+               fail(regex_constants::error_perl_extension, m_position - m_base);
+               return false;
+            }
+            v = -static_cast<int>(hash_value_from_capture_name(base, m_position));
+         }
+         else
+         {
+            v = -this->m_traits.toi(m_position, m_end, 10);
+         }
+         re_brace* br = static_cast<re_brace*>(this->append_state(syntax_element_assert_backref, sizeof(re_brace)));
+         br->index = v < 0 ? (v - 1) : 0;
+         if(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_close_mark)
+         {
+            // Rewind to start of (? sequence:
+            --m_position;
+            while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+            fail(regex_constants::error_perl_extension, m_position - m_base);
+            return false;
+         }
+         if(++m_position == m_end)
+         {
+            // Rewind to start of (? sequence:
+            --m_position;
+            while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+            fail(regex_constants::error_perl_extension, m_position - m_base);
+            return false;
+         }
+      }
+      else if((*m_position == charT('\'')) || (*m_position == charT('<')))
+      {
+         const charT* base = ++m_position;
+         while((m_position != m_end) && (*m_position != charT('>')) && (*m_position != charT('\'')))
+            ++m_position;
+         if(m_position == m_end)
+         {
+            // Rewind to start of (? sequence:
+            --m_position;
+            while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+            fail(regex_constants::error_perl_extension, m_position - m_base);
+            return false;
+         }
+         v = static_cast<int>(hash_value_from_capture_name(base, m_position));
+         re_brace* br = static_cast<re_brace*>(this->append_state(syntax_element_assert_backref, sizeof(re_brace)));
+         br->index = v;
+         if(((*m_position != charT('>')) && (*m_position != charT('\''))) || (++m_position == m_end))
+         {
+            // Rewind to start of (? sequence:
+            --m_position;
+            while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+            fail(regex_constants::error_perl_extension, m_position - m_base, "Unterminated named capture.");
+            return false;
+         }
+         if(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_close_mark)
+         {
+            // Rewind to start of (? sequence:
+            --m_position;
+            while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+            fail(regex_constants::error_perl_extension, m_position - m_base);
+            return false;
+         }
+         if(++m_position == m_end)
+         {
+            // Rewind to start of (? sequence:
+            --m_position;
+            while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+            fail(regex_constants::error_perl_extension, m_position - m_base);
+            return false;
+         }
+      }
+      else if(*m_position == charT('D'))
+      {
+         const char* def = "DEFINE";
+         while(*def && (m_position != m_end) && (*m_position == charT(*def)))
+            ++m_position, ++def;
+         if((m_position == m_end) || *def)
+         {
+            // Rewind to start of (? sequence:
+            --m_position;
+            while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+            fail(regex_constants::error_perl_extension, m_position - m_base);
+            return false;
+         }
+         re_brace* br = static_cast<re_brace*>(this->append_state(syntax_element_assert_backref, sizeof(re_brace)));
+         br->index = 9999; // special magic value!
+         if(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_close_mark)
+         {
+            // Rewind to start of (? sequence:
+            --m_position;
+            while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+            fail(regex_constants::error_perl_extension, m_position - m_base);
+            return false;
+         }
+         if(++m_position == m_end)
+         {
+            // Rewind to start of (? sequence:
+            --m_position;
+            while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+            fail(regex_constants::error_perl_extension, m_position - m_base);
+            return false;
+         }
+      }
+      else if(v > 0)
+      {
+         re_brace* br = static_cast<re_brace*>(this->append_state(syntax_element_assert_backref, sizeof(re_brace)));
+         br->index = v;
+         if(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_close_mark)
+         {
+            // Rewind to start of (? sequence:
+            --m_position;
+            while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+            fail(regex_constants::error_perl_extension, m_position - m_base);
+            return false;
+         }
+         if(++m_position == m_end)
+         {
+            // Rewind to start of (? sequence:
+            --m_position;
+            while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+            fail(regex_constants::error_perl_extension, m_position - m_base);
+            return false;
+         }
+      }
+      else
+      {
+         // verify that we have a lookahead or lookbehind assert:
+         if(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_question)
+         {
+            // Rewind to start of (? sequence:
+            --m_position;
+            while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+            fail(regex_constants::error_perl_extension, m_position - m_base);
+            return false;
+         }
+         if(++m_position == m_end)
+         {
+            // Rewind to start of (? sequence:
+            --m_position;
+            while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+            fail(regex_constants::error_perl_extension, m_position - m_base);
+            return false;
+         }
+         if(this->m_traits.syntax_type(*m_position) == regex_constants::escape_type_left_word)
+         {
+            if(++m_position == m_end)
+            {
+               // Rewind to start of (? sequence:
+               --m_position;
+               while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+               fail(regex_constants::error_perl_extension, m_position - m_base);
+               return false;
+            }
+            if((this->m_traits.syntax_type(*m_position) != regex_constants::syntax_equal)
+               && (this->m_traits.syntax_type(*m_position) != regex_constants::syntax_not))
+            {
+               // Rewind to start of (? sequence:
+               --m_position;
+               while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+               fail(regex_constants::error_perl_extension, m_position - m_base);
+               return false;
+            }
+            m_position -= 3;
+         }
+         else
+         {
+            if((this->m_traits.syntax_type(*m_position) != regex_constants::syntax_equal)
+               && (this->m_traits.syntax_type(*m_position) != regex_constants::syntax_not))
+            {
+               // Rewind to start of (? sequence:
+               --m_position;
+               while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+               fail(regex_constants::error_perl_extension, m_position - m_base);
+               return false;
+            }
+            m_position -= 2;
+         }
+      }
+      break;
+      }
+   case regex_constants::syntax_close_mark:
+      // Rewind to start of (? sequence:
+      --m_position;
+      while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+      fail(regex_constants::error_perl_extension, m_position - m_base);
+      return false;
+   case regex_constants::escape_type_end_buffer:
+      {
+      name_delim = *m_position;
+named_capture_jump:
+      markid = 0;
+      if(0 == (this->flags() & regbase::nosubs))
+      {
+         markid = ++m_mark_count;
+   #ifndef BOOST_NO_STD_DISTANCE
+         if(this->flags() & regbase::save_subexpression_location)
+            this->m_pdata->m_subs.push_back(std::pair<std::size_t, std::size_t>(std::distance(m_base, m_position) - 2, 0));
+   #else
+         if(this->flags() & regbase::save_subexpression_location)
+            this->m_pdata->m_subs.push_back(std::pair<std::size_t, std::size_t>((m_position - m_base) - 2, 0));
+   #endif
+      }
+      pb->index = markid;
+      const charT* base = ++m_position;
+      if(m_position == m_end)
+      {
+         // Rewind to start of (? sequence:
+         --m_position;
+         while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+         fail(regex_constants::error_perl_extension, m_position - m_base);
+         return false;
+      }
+      while((m_position != m_end) && (*m_position != name_delim))
+         ++m_position;
+      if(m_position == m_end)
+      {
+         // Rewind to start of (? sequence:
+         --m_position;
+         while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+         fail(regex_constants::error_perl_extension, m_position - m_base);
+         return false;
+      }
+      this->m_pdata->set_name(base, m_position, markid);
+      ++m_position;
+      break;
+      }
+   default:
+      if(*m_position == charT('R'))
+      {
+         ++m_position;
+         v = 0;
+         if(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_close_mark)
+         {
+            // Rewind to start of (? sequence:
+            --m_position;
+            while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+            fail(regex_constants::error_perl_extension, m_position - m_base);
+            return false;
+         }
+         goto insert_recursion;
+      }
+      if(*m_position == charT('&'))
+      {
+         ++m_position;
+         const charT* base = m_position;
+         while((m_position != m_end) && (this->m_traits.syntax_type(*m_position) != regex_constants::syntax_close_mark))
+            ++m_position;
+         if(m_position == m_end)
+         {
+            // Rewind to start of (? sequence:
+            --m_position;
+            while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+            fail(regex_constants::error_perl_extension, m_position - m_base);
+            return false;
+         }
+         v = static_cast<int>(hash_value_from_capture_name(base, m_position));
+         goto insert_recursion;
+      }
+      if(*m_position == charT('P'))
+      {
+         ++m_position;
+         if(m_position == m_end)
+         {
+            // Rewind to start of (? sequence:
+            --m_position;
+            while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+            fail(regex_constants::error_perl_extension, m_position - m_base);
+            return false;
+         }
+         if(*m_position == charT('>'))
+         {
+            ++m_position;
+            const charT* base = m_position;
+            while((m_position != m_end) && (this->m_traits.syntax_type(*m_position) != regex_constants::syntax_close_mark))
+               ++m_position;
+            if(m_position == m_end)
+            {
+               // Rewind to start of (? sequence:
+               --m_position;
+               while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+               fail(regex_constants::error_perl_extension, m_position - m_base);
+               return false;
+            }
+            v = static_cast<int>(hash_value_from_capture_name(base, m_position));
+            goto insert_recursion;
+         }
+      }
+      //
+      // lets assume that we have a (?imsx) group and try and parse it:
+      //
+option_group_jump:
+      regex_constants::syntax_option_type opts = parse_options();
+      if(m_position == m_end)
+      {
+         // Rewind to start of (? sequence:
+         --m_position;
+         while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+         fail(regex_constants::error_perl_extension, m_position - m_base);
+         return false;
+      }
+      // make a note of whether we have a case change:
+      m_has_case_change = ((opts & regbase::icase) != (this->flags() & regbase::icase));
+      pb->index = markid = 0;
+      if(this->m_traits.syntax_type(*m_position) == regex_constants::syntax_close_mark)
+      {
+         // update flags and carry on as normal:
+         this->flags(opts);
+         restore_flags = false;
+         old_case_change |= m_has_case_change; // defer end of scope by one ')'
+      }
+      else if(this->m_traits.syntax_type(*m_position) == regex_constants::syntax_colon)
+      {
+         // update flags and carry on until the matching ')' is found:
+         this->flags(opts);
+         ++m_position;
+      }
+      else
+      {
+         // Rewind to start of (? sequence:
+         --m_position;
+         while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+         fail(regex_constants::error_perl_extension, m_position - m_base);
+         return false;
+      }
+
+      // finally append a case change state if we need it:
+      if(m_has_case_change)
+      {
+         static_cast<re_case*>(
+            this->append_state(syntax_element_toggle_case, sizeof(re_case))
+            )->icase = opts & regbase::icase;
+      }
+
+   }
+   //
+   // now recursively add more states, this will terminate when we get to a
+   // matching ')' :
+   //
+   parse_all();
+   //
+   // Unwind alternatives:
+   //
+   if(0 == unwind_alts(last_paren_start))
+   {
+      // Rewind to start of (? sequence:
+      --m_position;
+      while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+      fail(regex_constants::error_perl_extension, m_position - m_base, "Invalid alternation operators within (?...) block.");
+      return false;
+   }
+   //
+   // we either have a ')' or we have run out of characters prematurely:
+   //
+   if(m_position == m_end)
+   {
+      // Rewind to start of (? sequence:
+      --m_position;
+      while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+      this->fail(regex_constants::error_paren, ::cutl_details_boost::re_detail::distance(m_base, m_end));
+      return false;
+   }
+   BOOST_ASSERT(this->m_traits.syntax_type(*m_position) == regex_constants::syntax_close_mark);
+   ++m_position;
+   //
+   // restore the flags:
+   //
+   if(restore_flags)
+   {
+      // append a case change state if we need it:
+      if(m_has_case_change)
+      {
+         static_cast<re_case*>(
+            this->append_state(syntax_element_toggle_case, sizeof(re_case))
+            )->icase = old_flags & regbase::icase;
+      }
+      this->flags(old_flags);
+   }
+   //
+   // set up the jump pointer if we have one:
+   //
+   if(jump_offset)
+   {
+      this->m_pdata->m_data.align();
+      re_jump* jmp = static_cast<re_jump*>(this->getaddress(jump_offset));
+      jmp->alt.i = this->m_pdata->m_data.size() - this->getoffset(jmp);
+      if((this->m_last_state == jmp) && (markid != -2))
+      {
+         // Oops... we didn't have anything inside the assertion.
+         // Note we don't get here for negated forward lookahead as (?!)
+         // does have some uses.
+         // Rewind to start of (? sequence:
+         --m_position;
+         while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+         fail(regex_constants::error_perl_extension, m_position - m_base, "Invalid or empty zero width assertion.");
+         return false;
+      }
+   }
+   //
+   // verify that if this is conditional expression, that we do have
+   // an alternative, if not add one:
+   //
+   if(markid == -4)
+   {
+      re_syntax_base* b = this->getaddress(expected_alt_point);
+      // Make sure we have exactly one alternative following this state:
+      if(b->type != syntax_element_alt)
+      {
+         re_alt* alt = static_cast<re_alt*>(this->insert_state(expected_alt_point, syntax_element_alt, sizeof(re_alt)));
+         alt->alt.i = this->m_pdata->m_data.size() - this->getoffset(alt);
+      }
+      else if(this->getaddress(static_cast<re_alt*>(b)->alt.i, b)->type == syntax_element_alt)
+      {
+         // Can't have seen more than one alternative:
+         // Rewind to start of (? sequence:
+         --m_position;
+         while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+         fail(regex_constants::error_bad_pattern, m_position - m_base, "More than one alternation operator | was encountered inside a conditional expression.");
+         return false;
+      }
+      else
+      {
+         // We must *not* have seen an alternative inside a (DEFINE) block:
+         b = this->getaddress(b->next.i, b);
+         if((b->type == syntax_element_assert_backref) && (static_cast<re_brace*>(b)->index == 9999))
+         {
+            // Rewind to start of (? sequence:
+            --m_position;
+            while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+            fail(regex_constants::error_bad_pattern, m_position - m_base, "Alternation operators are not allowed inside a DEFINE block.");
+            return false;
+         }
+      }
+      // check for invalid repetition of next state:
+      b = this->getaddress(expected_alt_point);
+      b = this->getaddress(static_cast<re_alt*>(b)->next.i, b);
+      if((b->type != syntax_element_assert_backref)
+         && (b->type != syntax_element_startmark))
+      {
+         // Rewind to start of (? sequence:
+         --m_position;
+         while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+         fail(regex_constants::error_badrepeat, m_position - m_base, "A repetition operator cannot be applied to a zero-width assertion.");
+         return false;
+      }
+   }
+   //
+   // append closing parenthesis state:
+   //
+   pb = static_cast<re_brace*>(this->append_state(syntax_element_endmark, sizeof(re_brace)));
+   pb->index = markid;
+   pb->icase = this->flags() & regbase::icase;
+   this->m_paren_start = last_paren_start;
+   //
+   // restore the alternate insertion point:
+   //
+   this->m_alt_insert_point = last_alt_point;
+   //
+   // and the case change data:
+   //
+   m_has_case_change = old_case_change;
+   //
+   // And the mark_reset data:
+   //
+   if(m_max_mark > m_mark_count)
+   {
+      m_mark_count = m_max_mark;
+   }
+   m_mark_reset = mark_reset;
+   m_max_mark = max_mark;
+
+
+   if(markid > 0)
+   {
+#ifndef BOOST_NO_STD_DISTANCE
+      if(this->flags() & regbase::save_subexpression_location)
+         this->m_pdata->m_subs.at(markid - 1).second = std::distance(m_base, m_position) - 1;
+#else
+      if(this->flags() & regbase::save_subexpression_location)
+         this->m_pdata->m_subs.at(markid - 1).second = (m_position - m_base) - 1;
+#endif
+      //
+      // allow backrefs to this mark:
+      //
+      if((markid > 0) && (markid < (int)(sizeof(unsigned) * CHAR_BIT)))
+         this->m_backrefs |= 1u << (markid - 1);
+   }
+   return true;
+}
+
+template <class charT, class traits>
+bool basic_regex_parser<charT, traits>::add_emacs_code(bool negate)
+{
+   //
+   // parses an emacs style \sx or \Sx construct.
+   //
+   if(++m_position == m_end)
+   {
+      // Rewind to start of sequence:
+      --m_position;
+      while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_escape) --m_position;
+      fail(regex_constants::error_escape, m_position - m_base);
+      return false;
+   }
+   basic_char_set<charT, traits> char_set;
+   if(negate)
+      char_set.negate();
+
+   static const charT s_punct[5] = { 'p', 'u', 'n', 'c', 't', };
+
+   switch(*m_position)
+   {
+   case 's':
+   case ' ':
+      char_set.add_class(this->m_mask_space);
+      break;
+   case 'w':
+      char_set.add_class(this->m_word_mask);
+      break;
+   case '_':
+      char_set.add_single(digraph<charT>(charT('$'))); 
+      char_set.add_single(digraph<charT>(charT('&'))); 
+      char_set.add_single(digraph<charT>(charT('*'))); 
+      char_set.add_single(digraph<charT>(charT('+'))); 
+      char_set.add_single(digraph<charT>(charT('-'))); 
+      char_set.add_single(digraph<charT>(charT('_'))); 
+      char_set.add_single(digraph<charT>(charT('<'))); 
+      char_set.add_single(digraph<charT>(charT('>'))); 
+      break;
+   case '.':
+      char_set.add_class(this->m_traits.lookup_classname(s_punct, s_punct+5));
+      break;
+   case '(':
+      char_set.add_single(digraph<charT>(charT('('))); 
+      char_set.add_single(digraph<charT>(charT('['))); 
+      char_set.add_single(digraph<charT>(charT('{'))); 
+      break;
+   case ')':
+      char_set.add_single(digraph<charT>(charT(')'))); 
+      char_set.add_single(digraph<charT>(charT(']'))); 
+      char_set.add_single(digraph<charT>(charT('}'))); 
+      break;
+   case '"':
+      char_set.add_single(digraph<charT>(charT('"'))); 
+      char_set.add_single(digraph<charT>(charT('\''))); 
+      char_set.add_single(digraph<charT>(charT('`'))); 
+      break;
+   case '\'':
+      char_set.add_single(digraph<charT>(charT('\''))); 
+      char_set.add_single(digraph<charT>(charT(','))); 
+      char_set.add_single(digraph<charT>(charT('#'))); 
+      break;
+   case '<':
+      char_set.add_single(digraph<charT>(charT(';'))); 
+      break;
+   case '>':
+      char_set.add_single(digraph<charT>(charT('\n'))); 
+      char_set.add_single(digraph<charT>(charT('\f'))); 
+      break;
+   default:
+      fail(regex_constants::error_ctype, m_position - m_base);
+      return false;
+   }
+   if(0 == this->append_set(char_set))
+   {
+      fail(regex_constants::error_ctype, m_position - m_base);
+      return false;
+   }
+   ++m_position;
+   return true;
+}
+
+template <class charT, class traits>
+regex_constants::syntax_option_type basic_regex_parser<charT, traits>::parse_options()
+{
+   // we have a (?imsx-imsx) group, convert it into a set of flags:
+   regex_constants::syntax_option_type f = this->flags();
+   bool breakout = false;
+   do
+   {
+      switch(*m_position)
+      {
+      case 's':
+         f |= regex_constants::mod_s;
+         f &= ~regex_constants::no_mod_s;
+         break;
+      case 'm':
+         f &= ~regex_constants::no_mod_m;
+         break;
+      case 'i':
+         f |= regex_constants::icase;
+         break;
+      case 'x':
+         f |= regex_constants::mod_x;
+         break;
+      default:
+         breakout = true;
+         continue;
+      }
+      if(++m_position == m_end)
+      {
+         // Rewind to start of (? sequence:
+         --m_position;
+         while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+         fail(regex_constants::error_paren, m_position - m_base);
+         return false;
+      }
+   }
+   while(!breakout);
+   
+   breakout = false;
+
+   if(*m_position == static_cast<charT>('-'))
+   {
+      if(++m_position == m_end)
+      {
+         // Rewind to start of (? sequence:
+         --m_position;
+         while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+         fail(regex_constants::error_paren, m_position - m_base);
+         return false;
+      }
+      do
+      {
+         switch(*m_position)
+         {
+         case 's':
+            f &= ~regex_constants::mod_s;
+            f |= regex_constants::no_mod_s;
+            break;
+         case 'm':
+            f |= regex_constants::no_mod_m;
+            break;
+         case 'i':
+            f &= ~regex_constants::icase;
+            break;
+         case 'x':
+            f &= ~regex_constants::mod_x;
+            break;
+         default:
+            breakout = true;
+            continue;
+         }
+         if(++m_position == m_end)
+         {
+            // Rewind to start of (? sequence:
+            --m_position;
+            while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+            fail(regex_constants::error_paren, m_position - m_base);
+            return false;
+         }
+      }
+      while(!breakout);
+   }
+   return f;
+}
+
+template <class charT, class traits>
+bool basic_regex_parser<charT, traits>::unwind_alts(std::ptrdiff_t last_paren_start)
+{
+   //
+   // If we didn't actually add any states after the last 
+   // alternative then that's an error:
+   //
+   if((this->m_alt_insert_point == static_cast<std::ptrdiff_t>(this->m_pdata->m_data.size()))
+      && m_alt_jumps.size() && (m_alt_jumps.back() > last_paren_start)
+      &&
+      !(
+         ((this->flags() & regbase::main_option_type) == regbase::perl_syntax_group)
+           &&
+         ((this->flags() & regbase::no_empty_expressions) == 0)
+        )
+      )
+   {
+      fail(regex_constants::error_empty, this->m_position - this->m_base, "Can't terminate a sub-expression with an alternation operator |.");
+      return false;
+   }
+   // 
+   // Fix up our alternatives:
+   //
+   while(m_alt_jumps.size() && (m_alt_jumps.back() > last_paren_start))
+   {
+      //
+      // fix up the jump to point to the end of the states
+      // that we've just added:
+      //
+      std::ptrdiff_t jump_offset = m_alt_jumps.back();
+      m_alt_jumps.pop_back();
+      this->m_pdata->m_data.align();
+      re_jump* jmp = static_cast<re_jump*>(this->getaddress(jump_offset));
+      BOOST_ASSERT(jmp->type == syntax_element_jump);
+      jmp->alt.i = this->m_pdata->m_data.size() - jump_offset;
+   }
+   return true;
+}
+
+#ifdef BOOST_MSVC
+#pragma warning(pop)
+#endif
+
+} // namespace re_detail
+} // namespace cutl_details_boost
+
+#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
+
+#endif