...than the rest of the program's allocations. But, garbage collectors typically require three to...

...the change, use this.

There are no allocations for this.

alias string  = immutable(char)[];

https...

...any sense in D to avoid additional allocations?

A D-Style String could be seen...

...case on the stack and uncommon big allocations on heap.
I'm not following you

...with heap allocations, although it can be clever with values (e.g. stack allocations).  So...

...for the compiler to be smart about allocations. So, those things ought to be language...

...IAllocator();
        alias base this;
        //--------------------------------

        ubyte* m_small_allocations = null;
        void*[4] m_free_lists;
        uint...

...struct) class DefaultAllocator : IAllocator
    {
        ubyte* m_small_allocations = null;
        void*[4] m_free_lists;
        uint...

...types:

- multiple array concatenation without multiple re-allocations, e.g. `a ~ b ~ c` gets rewritten...

...Maybe AllocatorList should be registering its GC allocations as roots?

As a solution/workaround, you...