...it should be explicitly said that accessing `__tag` is `@safe`.

Ah, OK. I missed that...

Also, the tag field itself will be visible to reflection (via `__traits(allMembers)`, which includes...

...with the tag field included.

When the DIP says "the size of the tag field...

...dlang.org/post/xtmwtmkhmufpzeyrsxsb@forum.dlang.org).

Tag names are optional, if you use the...

...the existence, size and alignment of the tag field has to be known. That's...

`__tag` is an rvalue property, and the intent is that the `size_t` it returns...

...tag property would be a getter as opposed to a direct field accessor the tag...

...opaque.

By "tag type" I assume you mean the type of the __tag property. Is...

...the destructor should run any time the tag changes, even if the new field has...

...method.

Ideally, most users would use pattern matching, and never have to check `__tag` directly.