rust/tests/ui/issues/issue-16739.rs
2023-01-11 09:32:08 +00:00

45 lines
1.3 KiB
Rust

// run-pass
#![feature(unboxed_closures, fn_traits)]
// Test that unboxing shim for calling rust-call ABI methods through a
// trait box works and does not cause an ICE.
struct Foo { foo: u32 }
impl FnMut<()> for Foo {
extern "rust-call" fn call_mut(&mut self, _: ()) -> u32 { self.foo }
}
impl FnOnce<()> for Foo {
type Output = u32;
extern "rust-call" fn call_once(mut self, _: ()) -> u32 { self.call_mut(()) }
}
impl FnMut<(u32,)> for Foo {
extern "rust-call" fn call_mut(&mut self, (x,): (u32,)) -> u32 { self.foo + x }
}
impl FnOnce<(u32,)> for Foo {
type Output = u32;
extern "rust-call" fn call_once(mut self, args: (u32,)) -> u32 { self.call_mut(args) }
}
impl FnMut<(u32,u32)> for Foo {
extern "rust-call" fn call_mut(&mut self, (x, y): (u32, u32)) -> u32 { self.foo + x + y }
}
impl FnOnce<(u32,u32)> for Foo {
type Output = u32;
extern "rust-call" fn call_once(mut self, args: (u32,u32)) -> u32 { self.call_mut(args) }
}
fn main() {
let mut f = Box::new(Foo { foo: 42 }) as Box<dyn FnMut() -> u32>;
assert_eq!(f.call_mut(()), 42);
let mut f = Box::new(Foo { foo: 40 }) as Box<dyn FnMut(u32) -> u32>;
assert_eq!(f.call_mut((2,)), 42);
let mut f = Box::new(Foo { foo: 40 }) as Box<dyn FnMut(u32, u32) -> u32>;
assert_eq!(f.call_mut((1, 1)), 42);
}