mock a function that returns a std::unique_ptr

Hello,

is it possible to mock a function that returns a std::unique_ptr? The faked function shall return a nullptr. How can I do that?

example for the real function:

class A {

  public:

    std::unique_ptr<int> getIntPtr() { return 10;}

};

What I have tried but failed:

auto fakedObj = FAKE_ALL<A>();

WHEN_CALLED(fakedObj->getIntPtr()).Return(nullptr);

or

std::unique_ptr<int> nullPtr;

WHEN_CALLED(fakedObj->getIntPtr()).Return(nullPtr);

Thanks in advance!