On Monday, 15 February 2021 at 07:26:56 UTC, Jack wrote:
I need to check if an instance is of a specific type derived
from my base class but this class has template parameter and
this type isn't available at time I'm checking it. Something
like:
class B { }
class A(T) : B { }
class X : B { }
class Z : B { }
auto c = can be any derived class from B
bool isX = cast(A!???) c !is null;
assert(isX);
an interface would work:
interface IA { }
class A(T) : B, IA { }
bool isX = cast(IA) c !is null;
assert(isX);
but I would have create one just for that. It feels a bit
hacky? also, does an empty interface like that increase the A
class memory size at all?
Hackier than hack:
bool isA(Object o)
{
return o && (cast(TypeInfo_Class)(typeid(o))).name == "A";
}
Of course, this is not recommended, I am sure that there is
another way to achieve what you want but with other design.
Unfortunately, your examples are too limited to have an idea.
