Kim Barrett wrote:
On Mar 24, 2010, at 5:20 PM, Bruno Santos wrote:
Qua, 2010-03-24 às 09:31 +0000, pete@pcbartlett.com escreveu:
Taking an example from way back at the start othis thread, in my personal experience a non-throwing version of lexical_cast<> would be very nice.
If I look at the cases where I pass user data through my libraries into boost libraries without some pre-validation, there are very few, and naturally these are the cases where the validation would as difficult as the "parse":
- boost::spirit::phrase_parse - Just returns a true/false, and I build a nice context-driven error message myself if necessary. - boost::lexical_cast - throws. Almost always needs to be caught and re-thrown. Why? Is it because you need to do some cleanup? Do you known what RAII is?
Exception translation, i.e. "re-thrown" as in "thrown in a different form". boost::bad_lexical_cast is not derived from my_project::invalid_user_input o or whatever. This happens a lot with boost::lexical_cast.
So a possible improvement to the lexical_cast design would be to have an optional template arg specifying the exception to throw for errors? Or perhaps some other general/global way of lexical_cast looking up an exception to throw instead of the ones it does? -- -- Grafik - Don't Assume Anything -- Redshift Software, Inc. - http://redshift-software.com -- rrivera/acm.org (msn) - grafik/redshift-software.com -- 102708583/icq - grafikrobot/aim,yahoo,skype,efnet,gmail