...runtime)

These behaviors do not represent RAII.
I suppose RAII has similarity to const/immutable...

...goes out of scope. (runtime)

I think RAII has similarity to const/immutable, which is...

...blit.

The inability to overload opAssign(typeof(this)) is a blocker for robust
RAII though.

...external resources, ever:

    struct RAII {...}
    var a = RAII("foo");
    var b = RAII("bar");
    a = b...

...the answer, especially if this means losing RAII.
Non-polymorphics iostreams is also no-go...

...stored
directly instead of as pointers, with RAII), but they're often passed
around as...

...and explicit type given, use scope for RAII" for the benefit of returning D programmers...

...less maintainable. (This is also my complaint about using RAII for scope guards in C++.)

...with different semantics =)
It's used for RAII (I guess you already know that, but...

...references break it, and when comes to RAII, you probably loose the ordering guarantees it...