...to pass a nested template function to a function declared outside the outer function scope?

...The presence of a name in the outer scope overrides the same name from the...

...1
copy outer
copy inner #1
copy inner #2
destroy inner #1
destroy outer
destroy...

https://issues.dlang.org/show_bug.cgi?id=1441
Issue 1441 depends on issue 2830...

...You can specify that you want the outer scope symbol by using in this line...

You'll need a pointer to the outer struct, or run it in an function...

...t work. In my case I'm able to move d() into the outer struct...

...This*);
alias Outer = Algebraic!(Inner, This*);

static assert(is(Outer.AllowedTypes == AliasSeq!(Inner, Outer*)));

---

$ dmd...

...ref T value) { this.value = value; }
}

struct Outer(T) {
    Inner!T inner;
    void opAssign(ref...

...even those could only strip away the outer layer of shared (i.e. what's...