Why does scope(success) have to use exceptions?

[Stewart Gordon]

On 17/01/2013 00:06, Era Scarecrow wrote:
<snip>
>   Consider a block containing a scope(exit) statement:
<snip>
>   However if compiler knows and can verify the code is unable to fail
> (thus exceptions are not needed) perhaps an enhancement request that
> could remove the unneeded try/catches...

The OP was talking about scope(success), not scope(exit). 
scope(success), by definition, won't be executed if the code fails.  If 
it does it by changing it to a try/finally, it has to generate extra 
code to test whether the code succeeded or not.  It's far simpler to 
just write out the scope(success) code at the end of the scope in 
question.  As such, the compiler is _pessimising_ the code.

OK, so it's a bit more complicated if the scope can be exited via a 
return, break, continue or (dare I mention?) goto statement, but even 
then it ought to be quite easy to make the compiler generate more 
efficient code.

This should be fixed, as it is discouraging use of scope(success).

Stewart.