Deallocators and Exceptions

[Martin von Loewis]

> > 1. The C++ standard prohibits deallocators from throwing exceptions.
> >    (I could not find such a requirement.)

There is no such requirement, but there should be one. This is Core
Issue 220

http://www.informatik.hu-berlin.de/~loewis/cwg_closed.html#220

As they point out, replacement functions must already have throw();
they don't see the need to require that for class deallocation
functions.

> > 2. Make the result undefined as what happens when a destructor throws
> >    an exception.  (See __cxa_new_vec ().)

In the light of that being consider ill-defined by some, making it 
undefined seems like a good choice.

> (2) would be consistent with what we've specified for throws from the
> destructor.  Any other observations?  

I think that part of the spec must be revised. It currently says

#  If the destructor throws an exception, the result is undefined. 

This is in violation of 15.5.1, [except.terminate]/1

# In the following situations exception handling must be abandoned for
# less subtle error handling techniques: ...
# - when the destruction of an object during stack unwinding (15.2)
#   exits using an exception, or

So I believe terminate must be called in this case.

Regards,
Martin