Hello! If I have a D struct like:

struct Foo
{
    int bar;

    void addToBar(int what) {
        bar += what;
    }
}

How would I call `addToBar` from C code? Would I need to put the `addToBar` function outside of the struct and mark it as `extern (C)` and in normal D code take advantage of UFCS or is there some magic C incantation?

I've scoured the forums and other places for anything about this but couldn't find any information whatsoever... so yeah. (or my Google-fu is terrible)

Thanks!

On Sunday, 25 June 2017 at 02:05:35 UTC, unleashy wrote:
> How would I call `addToBar` from C code?

You don't. Instead write it like:

struct Foo
{
    int bar;
}

extern(C) void addToBar(Foo* foo, int what) {
       foo.bar += what;
}


Then define it in C the same way and you call it the normal way from C.

But from D, you can UFCS call it:

Foo* foo = new Foo();
foo.addToBar(5); // cool


though I'd prolly just call it from D the same way you do from C too.

On Sunday, 25 June 2017 at 02:09:53 UTC, Adam D. Ruppe wrote:
> On Sunday, 25 June 2017 at 02:05:35 UTC, unleashy wrote:
>> How would I call `addToBar` from C code?
>
> You don't. Instead write it like:
>
> struct Foo
> {
>     int bar;
> }
>
> extern(C) void addToBar(Foo* foo, int what) {
>        foo.bar += what;
> }
>
>
> Then define it in C the same way and you call it the normal way from C.
>
> But from D, you can UFCS call it:
>
> Foo* foo = new Foo();
> foo.addToBar(5); // cool
>
>
> though I'd prolly just call it from D the same way you do from C too.

Thank you, this is what I suspected :)