1 error[E0015]: calls in constants are limited to constant functions, tuple structs and tuple variants
2 --> $DIR/issue-43105.rs:13:17
4 LL | const NUM: u8 = xyz();
7 error[E0080]: could not evaluate constant pattern
8 --> $DIR/issue-43105.rs:18:9
10 LL | const NUM: u8 = xyz();
11 | ----- calling non-const fn `xyz`
13 LL | NUM => unimplemented!(),
16 error: aborting due to 2 previous errors
18 Some errors occurred: E0015, E0080.
19 For more information about an error, try `rustc --explain E0015`.