How to access private variable of outer class from an inner struct

Jan 15, 2023

thebluepandabear

Jan 15, 2023

Paul Backus

Jan 15, 2023

Jan 15, 2023

Jan 15, 2023

Jan 15, 2023

January 15, 2023

Re: How to access private variable of outer class from an inner struct

Posted by thebluepandabear
in reply to Paul Backus

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thebluepandabear

Posted in reply to Paul Backus

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On Sunday, 15 January 2023 at 12:37:43 UTC, Paul Backus wrote:

On Sunday, 15 January 2023 at 12:26:15 UTC, thebluepandabear wrote:

If I have the following code:

class X {
    private int num;

    struct Y {
        // how to access num?
    }
}

How would I access num from Y?

Whenever I try to I get a compilation error.

I believe that it's possible for nested/inner classes, but I don't know if it's possible for structs.

Help would be apprciated.

I don't think this works for structs. As a workaround, you give your struct an explicit reference to the outer class, like this:

class X {
    private int num;

    struct Y {
        X outer;
        int fun() { return outer.num; }
    }
}

Thanks.

How will the variable outer become the reference to the current X object (if that makes sense?). Does the compiler do it automatically?

On Sunday, 15 January 2023 at 12:44:51 UTC, thebluepandabear wrote: > ... > How will the variable `outer` become the reference to the current `X` object (if that makes sense?). Does the compiler do it automatically? I think you'll need to do this: class X { private int num; struct Y { X outer; int fun() { return outer.num; } } Y y; this(){ y = Y(this); } } void main(){ import std.stdio : writeln; auto x = new X(); x.num = 10; writeln(x.num); writeln(x.y.fun()); } Prints: 10 10 Matheus.

On Sunday, 15 January 2023 at 13:23:20 UTC, matheus wrote: > On Sunday, 15 January 2023 at 12:44:51 UTC, thebluepandabear wrote: >> ... >> How will the variable `outer` become the reference to the current `X` object (if that makes sense?). Does the compiler do it automatically? > > I think you'll need to do this: > > class X { > private int num; > > struct Y { > X outer; > int fun() { return outer.num; } > } > > Y y; > this(){ > y = Y(this); > } > } > > void main(){ > import std.stdio : writeln; > auto x = new X(); > x.num = 10; > writeln(x.num); > writeln(x.y.fun()); > } > > Prints: > > 10 > 10 > > Matheus. ah, that's annoying, but I guess it's the only solution as it stands.

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