ices/62222.rs: fixed with errors

[github-actions]

Issue: rust-lang/rust#62222

#![feature(const_generics)]

use std::mem::{self, MaybeUninit};

#[repr(transparent)]
pub struct Vector<T, const N: usize>([T; N]);

impl<T, const N: usize> Vector<T, {N}> {
    pub fn x(self) -> T {
        let mut head = MaybeUninit::<T>::uninit();
        let mut tail = MaybeUninit::<[T; N - 1]>::uninit();
        let mut from = MaybeUninit::new(self);
        let tailp: *mut T = unsafe { mem::transmute(&mut tail) };
        let fromp: *mut MaybeUninit<T> = unsafe { mem::transmute(&mut from) };
        unsafe {
            head.as_mut_ptr().write(
                fromp
                    .replace(MaybeUninit::uninit())
                    .assume_init()
            );
        }
        for i in 1..N {
            unsafe {
                tailp.add(i - 1).write(
                    fromp
                        .add(i)
                        .replace(MaybeUninit::uninit())
                        .assume_init()
                );
            }
        }
        unsafe { tail.assume_init(); } // Drop the tail
        unsafe { head.assume_init() }
    }
}

fn main() {}

=== stdout ===
=== stderr ===
warning: the feature `const_generics` is incomplete and may cause the compiler to crash
 --> /home/runner/work/glacier/glacier/ices/62222.rs:1:12
  |
1 | #![feature(const_generics)]
  |            ^^^^^^^^^^^^^^
  |
  = note: `#[warn(incomplete_features)]` on by default

error: constant expression depends on a generic parameter
  --> /home/runner/work/glacier/glacier/ices/62222.rs:11:24
   |
11 |         let mut tail = MaybeUninit::<[T; N - 1]>::uninit();
   |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: this may fail depending on what value the parameter takes

error: constant expression depends on a generic parameter
  --> /home/runner/work/glacier/glacier/ices/62222.rs:11:24
   |
11 |         let mut tail = MaybeUninit::<[T; N - 1]>::uninit();
   |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: this may fail depending on what value the parameter takes

error: constant expression depends on a generic parameter
  --> /home/runner/work/glacier/glacier/ices/62222.rs:13:38
   |
13 |         let tailp: *mut T = unsafe { mem::transmute(&mut tail) };
   |                                      ^^^^^^^^^^^^^^
   |
   = note: this may fail depending on what value the parameter takes

error: constant expression depends on a generic parameter
  --> /home/runner/work/glacier/glacier/ices/62222.rs:32:18
   |
32 |         unsafe { tail.assume_init(); } // Drop the tail
   |                  ^^^^^^^^^^^^^^^^^^
   |
   = note: this may fail depending on what value the parameter takes

error: aborting due to 4 previous errors

==============