On 02/07/2012 03:48 AM, Steven Schveighoffer wrote:
On Mon, 06 Feb 2012 21:32:05 -0500, Vladimir Panteleev
<vladi...@thecybershadow.net> wrote:
On Tuesday, 7 February 2012 at 01:47:12 UTC, Jonathan M Davis wrote:
At present, assumeSafeAppend isn't pure - nor is capacity or reserve.
AFAIK, none of them access any global variables aside from GC-related
stuff (and new is already allowed in pure functions). All it would
take to make them pure is to mark the declarations for the C
functions that they call pure (and those functions aren't part of the
public API) and then mark them as pure. Is there any reason why this
would be a _bad_ idea?
If precedent means anything, assumeUnique is pure.
I think there is a difference -- assumeSafeAppend can make invalid data
that you did not pass to the pure function.
I'm still not sure if it's pure's job to protect data that you can get
to via pointer arithmetic, but I think the two cases are different.
-Steve
I think both cases are kinda equivalent, but you are right: pure does
not protect from undefined behaviour nor is it supposed to guarantee
memory safety.
