On 4/3/18 10:21 AM, ag0aep6g wrote:
On Tuesday, 3 April 2018 at 12:52:00 UTC, Andrei Alexandrescu wrote:
On 04/03/2018 07:36 AM, ag0aep6g wrote:
For constructors, we say that the first assignment is actually
initialization. The compiler might or might not put the .init value
down before calling the constructor. Doesn't matter, because the
constructor will overwrite it anyway, and nothing of value is lost.
What happens in fact is you are guaranteed the .init value is there.
Much later, well after semantic checking, the backend optimizer
removes dead assignments on primitive data.
So constructors, including const/immutable ones, basically work the same
as postblit already? You get an object pre-filled with some values, and
then you can "initialize" the fields some more if you want.
Unfortunately, I found out that it's not just "pre-filled with some
values". Member postblits are run before the containing postblit.
https://run.dlang.io/is/mt6eGa
So this means, the data that is available to the postblit has already
been processed.
It would only make sense to allow const postblits to have the same
constructor mechanism if the members all had no postblits.
-Steve
