13. Disabling copy solution

• Solution:

  • Prevent copying by declaring copy constructor and assignment private.

• However, the class itself could still access private class members!

• Therefore,

  • declare them as member functions, but do not define them;
    provide only function prototypes, but do not define the actual code.

• In attempt to copy objects within the class,

  • the compile process succeeds, but

  • the linker will fail to find the code it needs, resulting in

    • unresolved external symbol   error.