Readonly field for class type

[Seb]

On Thursday, 15 March 2018 at 13:44:20 UTC, Seb wrote:
> On Thursday, 15 March 2018 at 10:57:52 UTC, Mike Parker wrote:
>> On Thursday, 15 March 2018 at 10:55:16 UTC, Mike Parker wrote:
>>
>>> [...]
>>
>> Sorry. I overlooked that B.a is const.
>
> It still works, the `value` just needs to be `const` (or 
> `inout`) and _value needs to be used in updateValue:
>
> class A {
>     private int _value = 12;
>
>     int value() const { return _value; }
>     void updateValue() { _value = 13; }
> }
>
>
> auto a = new A();
> writeln(a.value);
> a.updateValue();
> writeln(a.value);
>
>
> In action: https://run.dlang.io/is/Tk1rY1
>
> @Robert: If you need this a lot, the accessors package might be 
> interesting to you:
>
> https://code.dlang.org/packages/accessors

(I meant @Andrey - sorry)