My day job is in working with C++ applications using Qt as the UI framework. Assuming the scope of your project is solely for a header definition (and some pseudo code), it should be straight forward to code up.
You typed "Don't forget to write contracts! " I think you may have a typo. I assume you just want getter and setter methods for each contact detail type, i.e. first name, last name, phone number etc.
That being said, you do have a vague spec. Strings and arrays are totally different beasts.
Using std::string to store data is very easy to do, but using char* arrays to store data is not so. Either way, we can discuss the specifics further so if you happen to like what I have to offer.
I'll admit that I'm using freelancer as a professional curiosity, hence the low bid.
Cheers.