Summary of the new feature/enhancement

As a scripter,
I want an operator that allows me to create a thread job from a single command
so that I can run commands on threads more easily in PowerShell.

This request is similar to the need for the recently added "ampersand background operator" (&) that allows you to run a command in a background job, but instead of running a command in a separate process, this operator would run the command in a separate thread.

To differentiate this way of running commands from background jobs, a different sigil would be used for the operator at the end of a command. The sigil that is chosen must be something that the parser currently does not support so that it wouldn't break existing scripts.

Proposed technical implementation details (optional)

To be consistent with the existing ampersand background operator, a sigil of &~ could be used. This sigil results in parser errors in versions of PowerShell that don't support the ampersand background operator.

In PowerShell 6.2, it results in a command not found error, because PowerShell runs everything in the statement up to & as a background job and then looks to run everything after that operator as a subsequent command. Technically this means it would be a breaking change for anyone with a command called ~, but only if they invoke that command immediately following a & operator in a script.

At any rate, here is what invocation might look like with a new glyph:

# Run a command in a threadjob
$job = Get-Process -Id 12345678 2>&1 &~
# Get the results from the threadjob
$job | Receive-Job