1 error[E0723]: function pointers in const fn are unstable
2 --> $DIR/issue-37550.rs:3:9
7 = note: for more information, see issue https://github.com/rust-lang/rust/issues/57563
8 = help: add #![feature(const_fn)] to the crate attributes to enable
10 error: aborting due to previous error
12 For more information about this error, try `rustc --explain E0723`.