It looks like an Appender field of a struct doesn't work when its
element type is the containing struct, i.e.
struct Foo
{
Appender!(Foo[]) fooAppender;
}
My guess is the problem is that the Appender needs to know how
big "Foo" is since it would be storing each element by value, but
since Foo's size depends on the size of the appender, we have a
circular dependency on knowing the storage size.
This theory is reinforced because modifying the element type of
fooAppender to "Foo*" fixes the problem.
struct Foo
{
Appender!(Foo*[]) fooAppender; // Works fine
}
One odd thing is that this error doesn't manifest until the
appender is used. It compiles just fine so long as you don't
actually use the appender, but once you put something in it or
access the data, you will get a compiler error at the location
where it was used, and not at the place where the appender was
defined. I'm not sure how it does this, but from the error
messages I've seen, it looks like the appender may be setting the
element type to "void" and silently continuing on as if this
isn't a problem.
Does anything know if this is a bug, or if it is as designed? If
it turns out that the functionality can't be supported, I think
that not throwing an error at the location of the appender
definition is a problem that should be addressed.
