Add first-class span types proposal

[333fred]

No description provided.

[CyrusNajmabadi]

Question. If we have your this, can we remove the special roles rules we have with collections to prefer spans over stays arrays? Would that just all fall out trivially once we have these conversions through preexisting better ness rules? If so, that would be lovely.

[333fred]

Question. If we have your this, can we remove the special roles rules we have with collections to prefer spans over stays arrays? Would that just all fall out trivially once we have these conversions through preexisting better ness rules? If so, that would be lovely.

Potentially. I haven't worked through all the scenarios, but I do believe it would make Span and ReadOnlySpan encompassing types in more scenarios, allowing the desired semantics to just fall out.

[CyrusNajmabadi]

Lovely!