> D can however be used without a GC if needed

Honest question: is it the case in practice though? Last time I checked D, you could disable the GC in theory, but in practice many things would fail to work, most importantly their standard library. As this been fixed since then?

Yes, it's the case in practice: I've written a lot of @nogc code. Some parts of the standard library require the GC, but not all of it, and the parts that I usually use are fine (std.algorithm, std.range, ...).

Since allocators landed, it's been a lot easier, and I've written a library that does C++-style smart pointers for D:

https://github.com/atilaneves/automem

> Rust achieves memory safety without a tracing GC. D has traditionally relied on the GC for that

Isn't D memory unsafe by default?

> Isn't D memory unsafe by default?

Yes, but it only takes this to guarantee it:

void main() @safe { // ... }

Not quite, that doesn't guard for safety in things like module constructors.