On 2009-12-31 09:58:06 -0500, Andrei Alexandrescu
<[email protected]> said:
The question of this post is the following: should output ranges be
passed by value or by reference? ArrayAppender uses an extra
indirection to work properly when passed by value. But if we want to
model built-in arrays' operator ~=, we'd need to request that all
output ranges be passed by reference.
I think modeling built-in arrays is the way to go as it makes less
things to learn. In fact, it makes it easier to learn ranges because
you can begin by learning arrays, then transpose this knowledge to
ranges which are more abstract and harder to grasp.
Beside, an extra indirection is wasteful when you don't need it. It's
easier to add a new layer of indirection when you need one than the
reverse, so the primitive shouldn't require any indirection.
// pseudo-method
void put(R, E)(ref R tgt, E e) {
tgt.front = e;
tgt.popFront();
}
I like that because it works especially well with arrays. Here's what
I'm thinking of:
char[10] buffer;
char[] remainingSpace = buffer[];
while (!remainingSpace.empty)
remainingSpace.put(getc());
// now buffer is full
writeln(buffer);
--
Michel Fortin
[email protected]
http://michelf.com/
