Thread overview
Abstract override behaviour
Feb 05, 2020
Claudiu
Feb 05, 2020
Ali Çehreli
Feb 05, 2020
Claudiu
Feb 05, 2020
Paul Backus
February 05, 2020
Hi dlang community,

Just started to learn D using Visual Studio 2007, latest VisualD (VisualD-v0.51.0-dmd-2.090.0-ldc2-1.19.0) and "The D Programming Language" by Andrei Alexandrescu.

I am trying to run most of the examples and had a surprise at chapter 1.6.1 "More Statistics. Inheritance" with the following code:

interface Stat {
    void accumulate(double x);
    ...
}

class IncrementalStat : Stat {
    ...
    abstract void accumulate(double x);
    ...
}

class Min : IncrementalStat {
    ...
    void accumulate(double x) { ... }
    ...
}

In class "Min" definition I am receiving this error: "cannot implicitly override base class method `IncrementalStat.accumulate` with  `Min.accumulate`; add `override` attribute"

After I update "Min" class to << override void accumulate(double x) >> everything works fine.
Can anybody clarify where is the problem.

Thanks in advance,
Claudiu

February 05, 2020
On 2/5/20 8:49 AM, Claudiu wrote:

> In class "Min" definition I am receiving this error: "cannot implicitly override base class method `IncrementalStat.accumulate` with  `Min.accumulate`; add `override` attribute"

Andrei's book is a little dated. Here is the errata:

  http://erdani.com/index.php?cID=109

Ali

February 05, 2020
On Wednesday, 5 February 2020 at 16:55:42 UTC, Ali Çehreli wrote:
> On 2/5/20 8:49 AM, Claudiu wrote:
>
>> In class "Min" definition I am receiving this error: "cannot implicitly override base class method `IncrementalStat.accumulate` with  `Min.accumulate`; add `override` attribute"
>
> Andrei's book is a little dated. Here is the errata:
>
>   http://erdani.com/index.php?cID=109
>
> Ali

Thanks a lot, I'll need to keep this errata close for future "surprises". I'm trying to learn idiomatic D. I think that this book is still relevant, but are there other recommended books?
February 05, 2020
On Wednesday, 5 February 2020 at 17:11:28 UTC, Claudiu wrote:
>
> Thanks a lot, I'll need to keep this errata close for future "surprises". I'm trying to learn idiomatic D. I think that this book is still relevant, but are there other recommended books?

https://p0nce.github.io/d-idioms/#Which-book-should-I-read?