ref is unsafe

[Jonathan M Davis]

On Thursday, January 03, 2013 23:50:37 Rob T wrote:
> My understanding was that in some cases that source code is not
> available to the compiler, which I would think means that
> preventing scope escaping cannot be 100% guaranteed, correct?

The source code is always available when compiling the function itself. So 
(assuming that scope is fully implemented - which it's not right now), the 
compiler will be able to verify that a scope parameter does not escape the 
function when it compiles that function.

What doesn't work is inferring function attributes at the call site, because 
that requires that the full code be available at the call site. And that's not 
necessarily true unless you're dealing with a templated function (which is 
part of why attribute inferrence only works with templated functions). But as 
long as you're talking about stuff that can be verified when the function itself 
is compiled, then the fact that the source code isn't necessarily available to 
the caller isn't an issue.

- Jonathan M Davis