Question

How do i test that an object is an instance of a particular class in D?

Something akin to Javascript’s instanceof keyword?

Answer 1

Use cast. It returns a null reference when you attempt to cast to a subclass it isn’t an instance of (like C++’s dynamic_cast).

auto a = new Base;
auto b = cast(Child) a;
assert(b is null);

a = new Child;
auto c = cast(Child) a;
assert(c !is null);