Xpressive walking past the end of string

[Simon Steele <s.steele@…>]

The following test code triggers an assertion in std::string::operator ++ under VC 8:

string s("> \"\" ");
string exp("(?P<f>.+):(?P<l>[0-9]+):((?P<c>[0-9]+):)?.*");

sregex re = sregex::compile(exp);
regex_search(s, re);

The previous call in the stack is boost::next, called from simple_repeat_matcher.hpp at line 181, right below a BUGBUG comment!

[Eric Niebler]

confirmed

[Eric Niebler]

(In [48661]) past-the-end iterator, fixes #2296

[sdiederich]

(In [48821]) silence MSVC8 warnings through pragmas, fixes #2296