error[E0277]: `()` cannot be safely transmuted into `W<'_>` --> $DIR/region-infer.rs:18:5 | LL | test(); | ^^^^^^ the size of `()` is smaller than the size of `W<'_>` | note: required by a bound in `test` --> $DIR/region-infer.rs:10:12 | LL | fn test<'a>() | ---- required by a bound in this function LL | where LL | W<'a>: TransmuteFrom< | ____________^ LL | | (), LL | | { Assume { alignment: true, lifetimes: true, safety: true, validity: true } }, LL | | >, | |_________^ required by this bound in `test` error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0277`.