On 31/05/13 23:58, Steven Schveighoffer wrote:
On Fri, 31 May 2013 00:48:47 -0400, Peter Williams
That makes programming much easier, doesn't it. I'll just avoid it by
using:
a = a ~ b;
instead of:
a ~= b;
If you care nothing for performance, this certainly is a way to go.
where I think it might be an issue or is that broken too?
This is a conservative "always reallocate" methodology, it should work
just like you allocated a new array to hold a and b.
That's what I assumed. I'm still getting used to the idea that "a <op>=
b" isn't just a shorthand for "a = a <op> b".
If a is frequently large, and b is frequently small, you will kill your
performance vs. a ~= b.
I doubt that I'll be doing it often enough (i.e. only when I think that
it's an issue) for it to matter. The only time I have two variables for
the same array is when I pass one to a function as a parameter and if
I'm intending to modify it in the function I'll pass it by reference so
that there's no gotchas.
I do like the idea that "~=" is generally cheap as it potentially makes
building lists easy (is there any need for the singly linked list in D?)
and I may modify some of my code. I've been allocating arrays using
"new array[size]" where I know that "size" will be the max needed but
that it may be too much (i.e. throwing away duplicates) inserting into
the array and then adjusting "length" to whatever I used. In the case,
where it's highly likely that the whole array will fit in a page I might
as well allocate an empty array and use "+=". NB there's only one copy
of the array.
Peter
