Rust is slowly overtaking C++. Microsoft, Google, and many others are switching to it step by step, even Linus Torvalds is switching part of the Linux code to Rust.
So, as today we had a question about creating a DLL in C and use it in Xojo, I though how hard (or easy) it would be the same in Rust.
So here are the steps:
Create the following tree of files:
xojo_rust
│
│ Cargo.toml
│
└───src
lib.rs
xojo_rust and src are folders
Cargo.toml is the project specification
lib.rs is our DLL code in Rust
Cargo.toml contents:
[package]
name = "xojorust"
version = "0.1.0"
edition = "2021"
[lib]
crate-type = ["cdylib"]
[dependencies]
lib.rs contents (yep, 4 lines):
#[no_mangle] // export symbol as is
pub fn double_value(value: i32) -> i32 { // return the double value as Int32
2 * value
}
It’s done.
Compile it going to the root folder xojo_rust and …
cargo build
You will end with something like this tree:
xojo_rust
│ .gitignore
│ Cargo.lock
│ Cargo.toml
│
├───src
│ lib.rs
│
└───target
│ .rustc_info.json
│ CACHEDIR.TAG
│
└───debug
│ .cargo-lock
│ xojorust.d
│ xojorust.dll
│ xojorust.dll.exp
│ xojorust.dll.lib
│ xojorust.pdb
│
├───.fingerprint
│ └───xojorust-6beb2fdf8a7024f9
│ dep-lib-xojorust
│ invoked.timestamp
│ lib-xojorust
│ lib-xojorust.json
│
├───build
├───deps
│ xojorust.d
│ xojorust.dll
│ xojorust.dll.exp
│ xojorust.dll.lib
│ xojorust.pdb
│
├───examples
└───incremental
└───xojorust-3bhhw63dtmlw9
│ s-gqcmv35bwe-1yvw50a.lock
│
└───s-gqcmv35bwe-1yvw50a-cn6ma2xqr28n52p6d9q4kyr9w
4zl3vjlcauf06loi.o
dep-graph.bin
query-cache.bin
work-products.bin
Notice the lib at .\target\debug\xojorust.dll
Let’s try it!
It works!
Have fun. 
