contract D {
	function f() external view returns (uint256) {
		return 42;
	}
}
contract C {
	D d;
	function() external view returns(uint256) immutable z;
	constructor() public {
		d = new D();
		z = d.f;
	}
	function f() public view returns (uint256) {
	assert(z.address == address(d));
	assert(z.selector == D.f.selector);
		return z();
	}
}
// ----
// f() -> 42