New issues should be submitted at svn.boost.org
        - don't forget to include your email address in the ticket!
      
        Currently open issues can be viewed here.
      
        All issues including closed ones can be viewed here.
      
- 
            Fix buffer over-run error when parsing certain invalid regexes, see
            #12222.
          
- 
            Fix detection of ICU in library build, see #12152.
          
- 
            Fix bug in case sensitivity change, see #11940.
          
- 
            Allow types wider than int in \x{}expressions (for char32_t etc), see #11988.
- 
            Change to lockfree implementation of memory cache, see PR#23.
          
- 
            Add support for Perl's backtracking control verbs, see #11205.
            Note however, that (*MARK) and operations on marks are not currently
            supported.
          
- 
            Fix incorrect range end when matching [[:unicode:]], see #11524.
          
- 
            Change POSIX reg_comp API to not check potentially uninitialized memory,
            note that code which was previously free from memory leaks (but none
            the less buggy, as it didn't call reg_free) will now leak. See #11472.
          
- 
            Make sub_match a valid C++ range type, see #11036.
          
- 
            Fixed some typos as in #10682.
          
- 
            Merged pull-request
            #6 for Coverity warnings.
          
- 
            Merged pull-request
            #7 for Coverity warnings.
          
- 
            Merged pull-request
            #8 for Coverity warnings.
          
- 
            Merged pull-request
            #10 to enable more build variants when linking to ICU.
          
- 
            Fix issue with ICU and partial matches, see #10114.
          
- 
            Removed delayload support for the ICU libraries: this doesn't work with
            the latest ICU releases (linker errors).
          
- 
            Moved to library-specific version number post the move to Git. And since
            we have one (minor) breaking change this gets bumped up from v4 to v5.
          
- 
            Breaking change: corrected behavior
            of basic_regex<>::mark_count()to match existing documentation,basic_regex<>::subexpression(n)changed to match, see #9227
- 
            Fixed issue #8903.
          
- 
            Fixed documentation typos from #9283.
          
- 
            Fixed bug in collation code that failed if the locale generated collation
            strings with embedded nul's, see #9451.
          
- 
            Apply patch for unusual thread usage (no statically initialized mutexes),
            see #9461.
          
- 
            Added better checks for invalid UTF-8 sequences, see #9473.
          
        Fixed issue #8569.
      
        Fixed Issues: #7744,
        #7644.
      
        Fixed issues: #589,
        #7084,
        #7032,
        #6346.
      
        Fixed issue with (?!) not being
        a valid expression, and updated docs on what constitutes a valid conditional
        expression.
      
        Fixed issues: #698,
        #5835,
        #5958,
        #5736.
      
        Fixed issues: #5223,
        #5353,
        #5363,
        #5462,
        #5472,
        #5504.
      
        Fixed issues: #4309,
        #4215,
        #4212,
        #4191,
        #4132,
        #4123,
        #4114,
        #4036,
        #4020,
        #3941,
        #3902,
        #3890
      
- 
            Added support for Functors rather than strings as format expressions.
          
- 
            Improved error reporting when throwing exceptions to include better more
            relevant information.
          
- 
            Improved performance and reduced stack usage of recursive expressions.
          
- 
            Fixed tickets #2802,
            #3425,
            #3507,
            #3546,
            #3631,
            #3632,
            #3715,
            #3718,
            #3763,
            #3764
          
- 
            Added support for many Perl 5.10 syntax elements including named sub-expressions,
            branch resets and recursive regular expressions.
          
- 
            Breaking change: empty expressions,
            and empty alternatives are now allowed when using the Perl regular expression
            syntax. This change has been added for Perl compatibility, when the new
            syntax_option_typeno_empty_expressions is set then the old behaviour
            is preserved and empty expressions are prohibited. This is issue #1081.
- 
            Added support for Perl style ${n} expressions in format strings (issue
            #2556).
          
- 
            Added support for accessing the location of sub-expressions within the
            regular expression string (issue #2269).
          
- 
            Fixed compiler compatibility issues #2244,
            #2514,
            and #2458.
          
- 
            Fix for non-greedy repeats and partial matches not working correctly
            in some cases.
          
- 
            Fix for non-greedy repeats on VC++ not working in some cases (bug report
            1515830).
          
- 
            Changed match_results::position() to return a valid result when *this
            represents a partial match.
          
- 
            Fixed the grep and egrep options so that the newline character gets treated
            the same as |.
          
- 
            Fixed broken makefiles.
          
- 
            Fixed configuration setup to allow building with VC7.1 - STLport-4.6.2
            when using /Zc:wchar_t.
          
- 
            Moved declarations class-inline in static_mutex.hpp so that SGI Irix
            compiler can cope.
          
- 
            Added needed standard library #includes to fileiter.hpp, regex_workaround.hpp
            and cpp_regex_traits.hpp.
          
- 
            Fixed a bug where non-greedy repeats could in certain strange circumstances
            repeat more times than their maximum value.
          
- 
            Fixed the value returned by basic_regex<>::empty() from a default
            constructed object.
          
- 
            Changed the definition of regex_error to make it backwards compatible
            with Boost-1.32.0.
          
- 
            Disabled external templates for Intel C++ 8.0 and earlier - otherwise
            unresolved references can occur.
          
- 
            Rewritten extern template code for gcc so that only specific member functions
            are exported: otherwise strange unresolved references can occur when
            linking and mixing debug and non-debug code.
          
- 
            Initialise all the data members of the unicode_iterators: this keeps
            gcc from issuing needless warnings.
          
- 
            Ported the ICU integration code to VC6 and VC7.
          
- 
            Ensured code is STLport debug mode clean.
          
- 
            Fixed lookbehind assertions so that fixed length repeats are permitted,
            and so that regex iteration allows lookbehind to look back before the
            current search range (into the last match).
          
- 
            Fixed strange bug with non-greedy repeats inside forward lookahead assertions.
          
- 
            Enabled negated character classes inside character sets.
          
- 
            Fixed regression so that [a-z-] is a valid expression again.
          
- 
            Fixed bug that allowed some invalid expressions to be accepted.
          
- 
            Completely rewritten expression parsing code, and traits class support;
            now conforms to the standardization proposal.
          
- 
            Breaking Change: The syntax options that can be passed to basic_regex
            constructors have been rationalized. The default option (perl) now has
            a value of zero, and it is now clearly documented which options apply
            to which regular expression syntax styles (perl, POSIX-extended, POSIX-basic
            etc). Some of the more esoteric options have now been removed, so there
            is the possibility that existing code may fail to compile: however equivalent
            functionality should still be available.
          
- 
            Breaking Change: POSIX-extended and POSIX-basic regular expressions now
            enforce the letter of the POSIX standard much more closely than before.
          
- 
            Added support for (?imsx-imsx) constructs.
          
- 
            Added support for lookbehind expressions (?<=positive-lookbehind)
            and (?<!negative-lookbehind).
          
- 
            Added support for conditional expressions (?(assertion)true-expression|false-expression).
          
- 
            Added MFC/ATL string wrappers.
          
- 
            Added Unicode support; based on ICU.
          
- 
            Changed newline support to recognise \f as a line separator (all character
            types), and \x85 as a line separator for wide characters / Unicode only.
          
- 
            Added a new format flag format_literal that treats the replace string
            as a literal, rather than a Perl or Sed style format string.
          
- 
            Errors are now reported by throwing exceptions of type regex_error. The
            types used previously - bad_expression and bad_pattern - are now just
            typedefs for regex_error. Type regex_error has a couple of new members:
            code() to report an error code rather than a string, and position() to
            report where in the expression the error occurred.
          
- 
            Fixed bug in partial matches of bounded repeats of '.'.
          
- 
            Completely rewritten pattern matching code - it is now up to 10 times
            faster than before.
          
- 
            Reorganized documentation.
          
- 
            Deprecated all interfaces that are not part of the regular expression
            standardization proposal.
          
- 
            Added regex_iterator and regex_token_iterator .
          
- 
            Added support for Perl style independent sub-expressions.
          
- 
            Added non-member operators to the sub_match class, so that you can compare
            sub_match's with strings, or add them to a string to produce a new string.
          
- 
            Added experimental support for extended capture information.
          
- 
            Changed the match flags so that they are a distinct type (not an integer),
            if you try to pass the match flags as an integer rather than match_flag_type
            to the regex algorithms then you will now get a compiler error.