Re: more on exceptions; new handler

[Paul Kienzle]

On Thu, Nov 14, 2002 at 09:50:50PM -0600, John W. Eaton wrote:
> Currently, I've defined macros in libcruft/misc/quit.h so that our new
> interrupt handling scheme can work with or without exceptions.  But
> does this really make sense?  Should we just start using exceptions?

We are at this point very dependent on a standard C++ compiler, so assuming
exceptions is not going to cost us anything in terms of portability.  

To be sure that this is the case, I would like to see your except.cc
extended to handle all the cases (fortran code, callbacks, dynamic loading)
so that we can see how well it does (or does not) work on various
platforms.  I'm too tired to do anything about it tonight though.

BTW, with C++ exceptions I presume the unwind_protect class is now
different?  Now you can define unwind_protect as a local variable which
does the unwind operation when it is destructed rather than performing an
unwind stack walk after a long jump.  At least, you can if C++ guarantees
that the destructor is called immediately when the variable goes out of
scope.  Is this any faster than what we have currently?  Or is it just
different.

This leads to another question, which is whether or not it is feasible
to implement evalin, which allows a function to evaluate a variable in
the caller's environment.  Not that I particularly need this feature.

Paul Kienzle
address@hidden