Find why this helper rejects a callback that increments captured state.
Rust
fn call_twice<F>(callback: F) -> (u32, u32)
where
F: Fn() -> u32,
{
(callback(), callback())
}
fn main() {
let mut sequence = 0;
let next = || {
sequence += 1;
sequence
};
println!("{:?}", call_twice(next));
}