Questionable const-checking for Drop with impossible bounds

Code

I tried this code:

pub struct Thing<T>(*const T) where [T]: Sized;

impl<T> Drop for Thing<T> where [T]: Sized {
    fn drop(&mut self) {}
}

// Requires dropping Thing<T> in const
pub const fn foo<T>(_x: Thing<T>) where [T]: Sized {}

This code errors in beta, with the following error:

error[E0493]: destructor of `Thing<T>` cannot be evaluated at compile-time
 --> src/lib.rs:8:21
  |
8 | pub const fn foo<T>(_x: Thing<T>) where [T]: Sized {}
  |                     ^^                              - value is dropped here
  |                     |
  |                     the destructor for this type cannot be evaluated in constant functions

For more information about this error, try `rustc --explain E0493`.

However, it compiles in nightly without any errors. It's unclear to me whether this is desirable.

Version it worked on

It failed to compile on: 1.99.0-beta.7 (2026-09-19 aa0593682acc35672839) on the playground.

Version with regression

It compiles without errors on: 1.100.0-nightly (2026-09-21 1303417c416e1595173d) on the playground.