| error[E0658]: cannot cast `dyn Fn()` to `dyn FnMut()`, trait upcasting coercion is experimental |
| --> $DIR/issue-11515.rs:11:38 |
| | |
| LL | let test = Box::new(Test { func: closure }); |
| | ^^^^^^^ |
| | |
| = note: see issue #65991 <https://github.com/rust-lang/rust/issues/65991> for more information |
| = help: add `#![feature(trait_upcasting)]` to the crate attributes to enable |
| = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date |
| = note: required when coercing `Box<(dyn Fn() + 'static)>` into `Box<(dyn FnMut() + 'static)>` |
| |
| error: aborting due to 1 previous error |
| |
| For more information about this error, try `rustc --explain E0658`. |