Any easy way to check if an object have inherited an interface?

[XavierAP]

On Monday, 22 July 2019 at 21:34:18 UTC, solidstate1991 wrote:
> It seems that I've to write my own function that searches in 
> the given object's classinfo.interfaces since I couldn't find 
> anything related in Phobos.

Do you mean...?

interface I {}
class C : I {}
void main()
{
	C c1;
	writeln(is(typeof(c1) : I));
}

No need for Phobos, core language:
https://dlang.org/spec/expression.html#IsExpression
https://dlang.org/spec/declaration.html#Typeof