First Draft: Nominal Sum Types via `enum union` and `switch` Expressions

[Meta]

On Thursday, 17 September 2026 at 12:24:56 UTC, Paul Backus wrote:
> On Tuesday, 15 September 2026 at 22:25:13 UTC, Meta wrote:
>> The compiler can lower a switch expression into a jump table, 
>> instead of the nested lambda calls of the current library 
>> solutions. Even if they're aggressively inlined, there's very 
>> little chance they'll get optimized as well as a language 
>> construct can be.
>
> I actually tested this a few years back. It turns out that, 
> assuming it can inline the callbacks, the compiler can optimize 
> `match` just as well as it can optimize a naked `switch` 
> statement:
>
> https://pbackus.github.io/blog/beating-stdvisit-without-really-trying.html

Nice, I stand corrected.