Recent change in core::any::TypeId breaks the type_id_hasher unittest

[hlopko]

Howdy,

The size of TypeId changed in rust-lang/rust@9e5573a, and the unittest type_id_hasher no longer builds:

cannot transmute between types of different sizes, or dependently-sized types
    |
638 |         assert_eq!(hasher.finish(), unsafe { core::mem::transmute::<TypeId, u64>(type_id) });
    |                                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: source type: `TypeId` (128 bits)
    = note: target type: `u64` (64 bits)

It seems to me that the commit doesn't affect the behavior of the anymap crate, it only affects the unittest. Could you please confirm that that is the case?

[reivilibre]

Seems right to me: the implementation of TypeId still only hashes the lower 64 bits (the u64) of its internal 128 bit number: https://doc.rust-lang.org/src/core/any.rs.html#655

So the unit test needs fixing, but otherwise I don't think anything is wrong here.

However relying on TypeId's hashing characteristics is perhaps a little bit unfortunate, but understandable.

[reivilibre]

This commit reivilibre@e561b1f fixes it in my fork. (Anyone should feel free to take the commit; it's under the same licence as the crate.)