1error[E0308]: mismatched types
2  --> $DIR/tail-typeck.rs:3:26
3   |
4LL | fn f() -> isize { return g(); }
5   |           -----          ^^^ expected `isize`, found `usize`
6   |           |
7   |           expected `isize` because of return type
8   |
9help: you can convert a `usize` to an `isize` and panic if the converted value doesn't fit
10   |
11LL | fn f() -> isize { return g().try_into().unwrap(); }
12   |                             ++++++++++++++++++++
13
14error: aborting due to previous error
15
16For more information about this error, try `rustc --explain E0308`.
17