State of -preview=rvaluerefparam

[Quirin Schroll]

Is `-preview=rvaluerefparam` going to be part of the language or 
has this course been abandoned?

For all other preview switches, I have the impression that 
they’re going to be part of the language once either the 
deprecation period is over/we get editions, or the feature is 
ironed out. In the following table, *Bugfix* means the former, 
*Feature* means the latter.

| Preview Switch        | Category |
|-----------------------|----------|
| `dip25`               | Feature  |
| `dip1000`             | Feature  |
| `dip1008`             | Feature? |
| `dip1021`             | Feature  |
| `bitfields`           | Feature  |
| `fieldwise`           | Bugfix   |
| `fixAliasThis`        | Bugfix   |
| `rvaluerefparam`      | **???**  |
| `nosharedaccess`      | Bugfix   |
| `in`                  | Bugfix   |
| `inclusiveincontracts`| Bugfix   |
| `fixImmutableConv`    | Bugfix   |
| `systemVariables`     | Feature  |

When conceptualizing or writing DIPs, it is crucial to take the 
prospected state of the language into account. For 
`rvaluerefparam`, it seems this is an abandoned path. It’s 
neither an extension of something the language can express nor is 
it a bugfix in the sense that if we could go back in time, we’d 
make it like this from the beginning.