Hi,
I have a few classes with need for deeper copying. I don't want a
bitwise copy necessarily. Ideally, I'd implement this(this).
I've thought about changing them to struct. However, the type
feels much more like a D class than a D struct. It's often passed
by reference, and it's not plain old data. Changing it to struct
for the sole benefit of "this(this)" seems to be a bad tradeoff.
(Use case: Backing up game states in a for
savestating/networking.)
I've resorted to a C++-style copy constructor:
this(T rhs) {
myvalue = rhs.myvalue;
myarray = rhs.myarray.dup;
// ...
}
Downside: Boilerplate, each member appears once in the
declarations, a second time in the copy constructor.
Alternative approaches seem to implement T T.dup() or T
T.clone(). Apparently, one has to pick one of these equally good
approaches, and stick with it throughout a codebase. It seems
good to implement it only for the classes that need it, to
minimize boilerplate.
Is that the state of the art?
-- Simon
