When searching for regex "(a)(?:b)" with the nosubs flag set, perl_matcher cores with failed assertion "m.subs() > 2" in >perl_matcher.hpp, match_results::set_second().
Confirmed: the patch that's going into cvs is at the end, if you don't want to apply that then, pass match_nosubs to the matching algorithm in place of compiling with nosubs. John. jm@fuji /cygdrive/c/data/boost/release/boost/boost/regex/v4 $ cvs diff -u johnmaddock@cvs.sourceforge.net's password: cvs diff: Diffing . Index: regex_compile.hpp =================================================================== RCS file: /cvsroot/boost/boost/boost/regex/v4/regex_compile.hpp,v retrieving revision 1.11.2.3 diff -u -r1.11.2.3 regex_compile.hpp --- regex_compile.hpp 12 May 2004 11:38:51 -0000 1.11.2.3 +++ regex_compile.hpp 14 May 2004 10:21:42 -0000 @@ -1435,7 +1435,8 @@ { case traits_type::syntax_colon: static_cast<re_detail::re_brace*>(dat)->index = 0; - --marks; + if((_flags & nosubs) == 0) + --marks; markid.pop(); markid.push(0); ++ptr; @@ -1445,7 +1446,8 @@ markid.pop(); markid.push(-1); common_forward_assert: - --marks; + if((_flags & nosubs) == 0) + --marks; ++ptr; // extend: dat = add_simple(dat, re_detail::syntax_element_jump, re_detail: :re_jump_size); @@ -1470,7 +1472,8 @@ case traits_type::syntax_hash: // comment just skip it: static_cast<re_detail::re_brace*>(dat)->index = 0; - --marks; + if((_flags & nosubs) == 0) + --marks; markid.pop(); mark.pop(); do{