poll about delete

[Andrei Alexandrescu]

bearophile wrote:
> Andrei Alexandrescu:
>> Agreed. I know how to fix it.
> 
> Can you tell the idea?

Either define an explicit Scope type, or use the alloca() as a default 
parameter trick.

> Another thing: currently somewhere in DMD there is some code that tests against returning a scoped object:
> 
> class Foo {}
> Foo bar() {
>     scope Foo f = new Foo;
>     return f;
> }
> void main() {}
> 
> That code generates the error:
> test.d(4): Error: escaping reference to scope local f
> 
> While currently this doesn't generate a compile-time error:
> 
> class Foo {}
> Foo bar() {
>     Foo f = scoped!Foo();
>     return f;
> }
> void main() {}
> 
> This bug report shows that 'scoped' can cause other bugs:
> http://d.puremagic.com/issues/show_bug.cgi?id=4214
> 
> But catching some of the most common bugs is positive, so can the code present in dmd used to catch and avoid the return of a scoped object be used to avoid the return of the library-defined scoped!() object?
> 
> Bye,
> bearophile

I think with memory safety it's a 0/1 proposition. The current "scope" 
keyword being "somewhat pregnant" is worse than not at all because it 
lulls its user into a false sense of security.


Andrei