Is there any way one can interface with Rust, such as with a struct, or a function?

I know that rust has an extern keyword, but I can't get it to work.

On Thursday, 29 September 2022 at 16:02:43 UTC, Ruby The Roobster wrote:

https://code.dlang.org/packages/rust_interop_d

Read the notes on memory management:

Only pass pointers as u64 as value type.

On Thursday, 29 September 2022 at 16:07:59 UTC, mw wrote:

This isn't the issue. I can't interface anything, period.

On Friday, 30 September 2022 at 00:18:42 UTC, Ruby The Roobster wrote:

Show an example of exactly what you're trying to do. Maybe it's some detail

On Friday, 30 September 2022 at 06:25:33 UTC, Imperatorn wrote:

lib.rs:

    #[derive(Debug)]
    struct Rectangle {
        width: u32,
        height: u32,
    }

    impl Rectangle {
        extern "cdecl" fn area(&self) -> u32 {
            self.width * self.height
        }

        extern "cdecl" fn can_hold(&self, other: &Rectangle) -> bool {
            self.width > other.width && self.height > other.height
        }
    }

main.d:

    struct Rectangle
    {
        uint width;
        uint hight;
        extern(C++) uint area();
        extern(C++) bool can_hold(Rectangle rhs)
    }

    void main()
    {
        auto rect1 = Rectangle(1,1);
        auto rect2 = Rectangle(0,0);
        assert(rect1.area == 1 && rect2.area == 0 && rect1.canHold(rect2));
    }

lib.rs was built as a "staticlib" using rustc, and the command I used was:

ldc2 -m64 main.d lib.lib

The output:

main.obj : error LNK2019: unresolved external symbol "public: unsigned int __cdecl Rectangle::area(void)" (?area@Rectangle@@QEAAIXZ) referenced in function _Dmain
main.obj : error LNK2019: unresolved external symbol "public: bool __cdecl Rectangle::can_hold(struct Rectangle)" (?can_hold@Rectangle@@QEAA_NU1@@Z) referenced in function _Dmain
main.exe : fatal error LNK1120: 2 unresolved externals
Error: C:\Program Files (x86)\Microsoft Visual Studio\2022\BuildTools\VC\Tools\MSVC\14.33.31629\bin\HostX64\x64\link.exe failed with status: 1120

Also, is it normal for the .lib file to be 11 megabytes?

extern(C++)？

Why do you think Rust export C++ linkage?

And why do you think Rust export some kind of OO object model linkage?

Do it in plain C style, you may make it work.

As said, check how it's done in:

https://code.dlang.org/packages/rust_interop_d