#![allow(dead_code, deprecated, unused_variables, unused_mut)]
fn add_one(x: usize) -> usize {
    x + 1
}
unsafe fn add_one_unsafely(x: usize) -> usize {
    x + 1
}
fn main() {
    let safe_ptr: fn(usize) -> usize = add_one;
    let unsafe_ptr: unsafe fn(usize) -> usize = add_one_unsafely;
    let really_safe_ptr: unsafe fn(usize) -> usize = add_one;
}