C++ doesn't have the concept of interfaces. What it does have though is the concept of abstract classes and functions:

struct IMyInterface {
	virtual void MyFunction() = 0; // the "= 0;" marks a method as abstract
}

struct MyImplementaiton : IMyInterface {
	virtual void MyFunction() override {
		... implementation ...
	}
}

<aside> 💡 Note: if one of the functions is marked as abstract in C++, the whole class is marked as abstract and cannot be instantiated

</aside>