-fno-exceptions documentation

[Paolo Carlini]

Paolo Carlini wrote:

>Maybe I have a concern, however: I think people are also using libsupc++
>*alone*, without the rest of the libstdc++ library, I'm not sure what we
>should do in that case...
>  
>
... probably, just having X<void>::__throw_bad_alloc in a libsupc++
header would do...

All in all, the whole approach seems not so different from
__verbose_terminate_handler, already part of libsupc++ in namespace
__gnu_cxx, only the "weak linkage" tricks are more delicate.

Paolo.