error[E0015]: cannot call non-const fn `Vec::::len` in constant functions --> $DIR/issue-94675.rs:11:27 | LL | self.bar[0] = baz.len(); | ^^^^^ | = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants error[E0015]: cannot call non-const operator in constant functions --> $DIR/issue-94675.rs:11:17 | LL | self.bar[0] = baz.len(); | ^^^ | note: impl defined here, but it is not `const` --> $SRC_DIR/alloc/src/vec/mod.rs:LL:COL = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants error: aborting due to 2 previous errors For more information about this error, try `rustc --explain E0015`.