Documentation of Send/Sync is incomplete/outdated (also in UnsafeCell)

[RalfJung]

The documentation for Sync says

Users writing their own types with interior mutability (or anything else that is not thread-safe) should use the NoSync marker type (from std::marker) to ensure that the compiler doesn't consider the user-defined type to be Sync.

However, there is no NoSync type anymore.

Send has virtually no documentation.

UnsafeCell says

UnsafeCell doesn't opt-out from any marker traits, instead, types with an UnsafeCell interior are expected to opt-out from those traits themselves.

which, if I am informed correctly, is not true anymore - Send/Sync are removed automatically for anything containing an UnsafeCell.

[steveklabnik]

Which documentation is this?

[RalfJung]

http://doc.rust-lang.org/std/marker/trait.Sync.html and http://doc.rust-lang.org/std/marker/trait.Send.html and http://doc.rust-lang.org/std/cell/struct.UnsafeCell.html