The D programming language has an optional garbage collector. [0][1]

With the @nogc attribute the compiler can check/enforce that your function doesn't depend on the GC. [2]

[0] https://dlang.org/spec/garbage.html

[1] https://news.ycombinator.com/item?id=33382159

[2] https://dlang.org/spec/function.html#nogc-functions