What prevents `handler` from being moved or copied?

[Pennycook]

Specification Version

SYCL 2020 (Revision 9)

Section Number(s)

• Section 4.9.4. Command group handler class, https://registry.khronos.org/SYCL/specs/sycl-2020/html/sycl-2020.html#sec:handlerClass

Issue Description

The specification says:

It is disallowed for an instance of the SYCL handler class to be moved or copied.

It is unclear whether "disallowed" means that the implementation must prevent this somehow, or if it's simply undefined behavior. The definition of the handler class does not show that the copy and move constructors are deleted, nor that they exist but are private.

Note that the issue and potential fixes are very similar to those being discussed for the group class in #627.

Code Example (Optional)

No response