[cairo] cairomm exception handling questions

[Ian Britten]

Hi all,
Just a couple of elementary exception handling questions, related
to cairomm.  (I'm trying to get my groundwork laid correctly)

- After some trial-and-error (And grubbing through the cairomm
   source code), I've discovered that passing an invalid file name
   to PdfSurface::create() doesn't throw a Cairo::logic_error
   exception, but instead, a std::ios_base::failure exception.
   Wouldn't it make it more consistent to throw all cairomm
   exceptions as Cairo::logic_error?  Currently, I (as a programmer
   trying to trap all Cairo exceptions and downgrading them to
   errors) must add multiple 'catch' statements to all my 'try'
   statements.  That seems like it'll get repetitive/tedious pretty
   quickly..  :(

- What am I expected to do with a Cairo::logic_error exception?  I
   had been planning to try use the ErrorStatus (cairo_status_t) to
   return a meaningful error to the calling code.  However, it seems
   that I can't access the status (private, no 'get').  Thus, it
   seems that all I can do is return a "Something went wrong in Cairo"
   error, from every 'catch' that I write...

Thanks for any info, and sorry if I've missed something basic!  I'm
just trying to make sure I get off on the right foot!
Ian