No, that function is my solution that I use in the random tests to verify agains the user's solution. I am not sure how to actually make this happen. Should I put my solution in the preloaded section? How do I hide it so that no one can call it?

Edit: I have done that. I am not getting compiler errors when I attempt an empty solution (which obviously doesn't pass the tests). Could you check now?

I have the same error!! Don't know how to solve it. Please Help! Up vote if you have the same problem

I agree with forever young. The interfaces are not very well designed in my opinion. The entire solution can get rid of the Engine interface and class altogether and it would still work. TDD development dictates: Do the minimal amount of work possible in order to pass the tests. The redundancy is not needed.

Hey guys, I need some help> I pass all the tests except for this one:
Car1RandomTests
Expected: equal to 2
Actual: 1.99

The description says to round to 2 decimal places in the display, It would be usefull to know what the tests is doing. The only operations I am using in the code are double precission addition and substraction. There are no casts, no division or multiplication and no loss of precission except floating point roundoff inherent in the double representation in the processor, and only the rounding in the Fuel tank display. Any thoughts??

Not in terms of passing the challenges in this page, but it would be if you were to be programming for a target whose compiler does not support C++11, as is the case with embebdded devices toolchain.

Good solution but requires C++11.