Boost::regex brackets after \\??

[NLegende@…]

For example declare: const boost::regex format("match
??(match)"); and run program.

If I use brackets after
?? I get error "Microsoft C++ exception: boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<boost::regex_error> >"

If I use brackets after (
?)? then it works.

[John Maddock]

This is an MSVC / std C++ issue, the character sequence ??( is treated as a trigraph by the compiler, so the string passed to Boost.Regex isn't the one you think you're passing :-(

See ​http://msdn.microsoft.com/en-us/library/bt0y4awe.aspx

HTH, John.