#![feature(const_trait_impl, const_vec_string_slice)]
struct Foo<'a> {
bar: &'a mut Vec<usize>,
}
impl<'a> Foo<'a> {
const fn spam(&mut self, baz: &mut Vec<u32>) {
self.bar[0] = baz.len();
//~^ ERROR: cannot call
fn main() {}