pls can anyone help me with this debugging problem?

1. The method Function::Evaluate() is declared as const, but the implementation of the function either tries to modify a member of the instance, or calls a member function that is not const.

Solution: Check what element(s) in the function implementation are non-const and either change the implementation to only use const members, or, if you really mean to change values, remove the const qualifier from the function signature.

2. The compiler found two overloads for the function Function::GetReference(), but neither function signature matches how it is used

Solution: since the error mentions the 'this' pointer, it may just be a subsequent error of 1 - i. e. the reason that the compiler couldn't match one of the overloads may be that 'this' in the current is const, but none of the function overloads is a const function. If that is not the case, check the line of code that the error message refers to and make sure that the way you call the function matches the signature of the function that you mean to call.

3. While the error message itself is clear, the code the message points to may not provide an immediate hint where the problem lies, as it may be in code that is not your own: it seems that you defined a list of objects of type CObject. The class list itself declares an assignment operator which copies the contents of the list, and therefore needs to access the assignment operator of it's elements, in this case CObject::operator=(). Since that member function was declared private (or protected), the CList implementation cannot access it, resulting in the error message.

Solution: I'm not sure if the class CObject you're using is one you defined yourself, or one provided by a framework such as MFC. I assume it's the latter. In this case, defining a list of elements of type CObject doesn't make any sense! What you meant to do is define a list of elements that are of some (unknown) type derived from CObject. If that assumption is accurate, the correct thing to do is define a list of elements of type pointer to CObject instead.

P.S.: all these answers and solutions can be derived from just looking at the error messages and understanding their meaning. Looking the error codes up on MSDN helps, too. That said, it would be easier to give more accurate advice if you had simply posted the lines of code that these error messages point to!