1 //! Small example of how to use `anyref`s.
2
3 // You can execute this example with `cargo run --example anyref`
4
5 use wasmtime::*;
6
main() -> Result<()>7 fn main() -> Result<()> {
8 println!("Initializing...");
9 let mut config = Config::new();
10 config.wasm_reference_types(true);
11 config.wasm_function_references(true);
12 config.wasm_gc(true);
13 let engine = Engine::new(&config)?;
14 let mut store = Store::new(&engine, ());
15
16 println!("Compiling module...");
17 let module = Module::from_file(&engine, "examples/anyref.wat")?;
18
19 println!("Instantiating module...");
20 let instance = Instance::new(&mut store, &module, &[])?;
21
22 println!("Creating new `anyref` from i31...");
23 let i31 = I31::wrapping_u32(1234);
24 let anyref = AnyRef::from_i31(&mut store, i31);
25 assert!(anyref.is_i31(&store)?);
26 assert_eq!(anyref.as_i31(&store)?, Some(i31));
27
28 println!("Touching `anyref` table...");
29 let table = instance.get_table(&mut store, "table").unwrap();
30 table.set(&mut store, 3, anyref.into())?;
31 let elem = table
32 .get(&mut store, 3)
33 .unwrap() // assert in bounds
34 .unwrap_any() // assert it's an anyref table
35 .copied()
36 .unwrap(); // assert the anyref isn't null
37 assert!(Rooted::ref_eq(&store, &elem, &anyref)?);
38
39 println!("Touching `anyref` global...");
40 let global = instance.get_global(&mut store, "global").unwrap();
41 global.set(&mut store, Some(anyref).into())?;
42 let global_val = global.get(&mut store).unwrap_anyref().copied().unwrap();
43 assert!(Rooted::ref_eq(&store, &global_val, &anyref)?);
44
45 println!("Passing `anyref` into func...");
46 let func = instance.get_typed_func::<Option<Rooted<AnyRef>>, ()>(&mut store, "take_anyref")?;
47 func.call(&mut store, Some(anyref))?;
48
49 println!("Getting `anyref` from func...");
50 let func =
51 instance.get_typed_func::<(), Option<Rooted<AnyRef>>>(&mut store, "return_anyref")?;
52 let ret = func.call(&mut store, ())?;
53 assert!(ret.is_some());
54 assert_eq!(ret.unwrap().unwrap_i31(&store)?, I31::wrapping_u32(42));
55
56 println!("GCing within the store...");
57 store.gc(None)?;
58
59 println!("Done.");
60 Ok(())
61 }
62