On Wed, 17 Aug 2011 13:15:27 -0400, Lars T. Kyllingstad
<public@kyllingen.nospamnet> wrote:
On Wed, 17 Aug 2011 10:19:31 -0400, Steven Schveighoffer wrote:
On Wed, 17 Aug 2011 00:05:54 -0400, Jonathan M Davis
<jmdavisp...@gmx.com> wrote:
So, the question is, should a range-based function have the same
behavior for
all forward ranges regardless of whether they're value types or
reference types? Or should the caller be aware of whether a range is a
value type or a
reference type and call save if necessary? Or should the caller just
always
call save when passing a forward range to a function?
Probably not helpful, since the establishment seems to be set in their
opinions, but I'd recommend saying ranges are always structs, and get
rid of the save concept, replacing it with an enum solution. The
current save regime is a fallacy, because it's not enforced. It's as
bad as c++ const.
At the very least, let's wait until someone actually comes up with a
valid use case for reference-based forward ranges before changing any
code. So far, all I've seen is boilerplate *RangeObject, no real
usages.
As long as most functions in std.algorithm don't take the ranges as ref
arguments, you need to use a reference-based range whenever you want the
function to consume the original range.
BTW, this is why I suggested earlier that we add a byRef range. If you
absolutely want the function foo() to consume your range, write
foo(byRef(myRange));
Do you have a real example besides foo which makes sense on both byRef and
by value ranges?
I think it's rather important for the function implementation to know
what's happening with its range while using it.
-Steve
