On Mon, 12 Oct 1998, Xavier Leroy wrote:

> I've never found a convincing example of a type or exception
> declaration local to an expression.

I know only one useful example of the local exceptions. I include it
in my first letter. But it's enough important example (by my opinion):
This is structured goto from complex nested construction with returning
value.

Since exceptions can't be polymorphic, for each type of returned value we 
need specific exception. I don't know any other convenient way to do
this.

Regards, 
Anton E. Moscal