Returning dynamic array from the function

[Jonathan M Davis]

On Wednesday, October 17, 2012 21:46:50 bearophile wrote:
> sclytrack:
> > It doesn't give an error when marking the function with safe.
> > 
> > @safe
> > int[] create()
> > {
> > }
> 
> I think marking it @safe is not relevant. In theory a good type
> system should give an error message on similar code. I don't know
> if D is supposed to spot similar error situations.

@safe is irrelevant, because the code is just plain broken in the first place. 
It really should be an error ( 
http://d.puremagic.com/issues/show_bug.cgi?id=7087 ), just like it's an error 
to return a pointer to a local variable. But unfortunately, since all it takes 
to trick the compiler is passing the slice (or pointer in the case of the 
pointer to a local variable) to a function which then returns that 
slice/pointer, there's no way for the compiler to always catch it for you.

The only way that @safe could really be applicable would be if it became 
@system to take the address of a local variable or to slice a static array. 
And perhaps it should be, but that and catching the most obvious cases are all 
that the compiler could do to catch this for you.

- Jonathan M Davis