> Also I see the existence of boost::regbase::use_except and > boost::regbase::failbit > I don't see how to use them in a way to enable/disable exceptions in > regular > expressions, dispite probably the activation of the general > BOOST_NO_EXCEPTIONS > (Shame on me!). > > Question: It seems, that boost::regbase::use_except is always active, > because it > is or'ed to the flags arguments in every(?) c'tor or assignment of > reg_expression. > Is that true?
Yes. > If that is true: Why does the flag regbase::use_except (officially) > exist? It's a historical accident and should have been removed from the docs. > Lets assume, that throwing boost::bad_expression is a general policy (I > can live with that), > it would be **very** nice to have at least one (probably static) member > function, > which takes a textual regular expression and an optional bunch of > regbase flags as arguments and > returns a bool, which simply returns true in case of a valid expression, > otherwise false. What > do you think of that? You could call the undocumented member function set_expression which would return 0 on success, alternatively you're back to rolling your own, BTW why do you want this? If a regular expression is valid, then presumably at some point you would want to use it? I ask because the job of checking the expression for validity is essentially the same as compiling it to a state machine. John _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost
