Re: [Boost-users] Boost regexp (Perl) throws initialization error for [^\0x21-\0xfe]

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If my code contains the following regexp,

const boost::tregex non_printables(__T("[^\0x21-\0x7E]+"));

Don't forget that your pattern is scanned first by the C++ compiler. In this case, this means that \0x21 is never seen by the RegExp engine; instead, it sees a NUL character (ASCII 0) followed by "x21". NUL is not valid in any pattern and thus an exception is thrown. Use double backslashes to get a backslash through to the engine.

Quite right, and just to add to that: it's very helpful if you add a try...catch handler in main so that unhandled exceptions don't crash the application. Or to put it another way, error handling is a "good thing" :-) John.