On Sunday, March 06, 2016 15:25:46 HSteffenhagen via Digitalmars-d-learn
wrote:
> In the https://dlang.org/spec/operatoroverloading.html opAssign
> is declared as
>
> void opAssign(S rhs);
>
> in the example.
>
> From C++ I'm used to return *this when overloading assignment
> operators to allow chaining of assignments (or somewhat more
> rarely, weird tricks for if and while statements), is that not
> done in D as a rule or is the example just weird? Same question
> for the
> opOpAssign family.
void opAssign(S rhs);
will work, but it's not the most flexible. Ideally, the various overloaded
assignment operators would return "this" by ref. e.g.
ref S opAssign(S rhs)
{
...
return this;
}
which is essentially what you do in C++. Without returning by ref, you can't
chain assignments, which is why return by ref is preferable even if it's not
required. The example in the documentation should probably be modified to
return by ref, but void will work - just not with chained assignments.
- Jonathan M Davis
