On Wednesday, 22 February 2012 at 20:59:15 UTC, Jonathan M Davis
wrote:
speed [...] is really its whole point of existance. I don't
know why else you'd ever use appender.
[...]
- Jonathan M Davis
A use case is to give identity to a built-in array.
Consider this:
class MyClass {
private MyData[] theData;
public @property MyData[] data() {
return theData;
}
...
}
MyClass m = new MyClass();
m.data ~= new MyData();
//Nothing got appended:
assert(m.data.length == 0);
For the 95% of the use cases, that is the desired
behaviour. You don't want anyone appending to
your private array. If you wanted to, you would
have defined MyClass.append(myData).
But there are a few cases where you want to
give identity to the array, and let anyone who
has a "handle" to it, to be able to append it.
(another case is while porting code from languages
that don't represent arrays as ranges, and return
them as getters).
--jm
