DIP49 - Define qualified postblit

[Daniel Murphy]

"Kenji Hara" <k.hara.pg at gmail.com> wrote in message 
news:mailman.336.1384083327.9546.digitalmars-d at puremagic.com...
>
> This is valid. Because not only strongly pure function will return unique
> object.
>
> For example:
>  immutable(int)[] foo(int[] iarr) pure { ... }
>  int[] marr = foo([1,2,3]);
>  // foo will never return the arr argument (without unsafe cast).
>

This one is incorrect, the value returned from foo could be an immutable 
global.  The unique conversion is only capable of changing non-mutable to 
immutable, not the other way around.

Maybe you meant something like this?

int[] foo(const(int)[] iarr) pure { ... }