On Sat, 18 Sep 2010 17:20:31 -0400, Jonathan M Davis <jmdavisp...@gmx.com>
wrote:
On Saturday 18 September 2010 09:58:15 Steven Schveighoffer wrote:
In reality, you cannot make save const, unless you want to do a deep
copy
(but I recommend against that, save should be a quick operation).
Well, I was trying to make a deep copy (that's what it does if it
doesn't have
an array in it anyway). I suppose whether it really needs to be const or
not
depends on what you're trying to do with it. I'm definitely trying to
create a
range here, and if save() is supposed to make a copy of the range,
whether that
needs to be a shallow copy or a deep copy depends on what the
std.algorithm stuff
does with it. When I think copy, I usually think deep copy, but that's
not
necessarily the case. I will have to enquire as to the intent of save().
For
value types, shallow copy and deep copy are the same, so it's not an
issue. But
for class ranges or struct ranges with references, it does become an
issue.
You don't want a deep copy of a range. All you want to copy is the
iteration state, not the data.
save is definitely supposed to be shallow. I.e. you should copy the range
itself, not what the range points to.
-Steve
