C2512: no appropriate default constructor availabl

This error usually occurs when you implement the constructor function of a derived class and forget to include parameter passing to the base class constructor function. For example assume that CDerived is derived from CBase and that the CBase constructor function requires one parameter (e.g., int A). If you define the CDerived constructor function as:

CDerived::CDerived(int A, int B) { ... }

the compiler will issue the above error message on the line containing the function header of CDerived::CDerived() because you haven't provided instructions for routing the parameter A to CBase::CBase(). Because you didn't provide instructions the compiler assumes that CBase::CBase() requires no arguments and it complains because no version of CBase::CBase() has been defined that accepts zero arguments.

If you intended to provide a version of CBase::CBase() that requires no arguments then the error message indicates that you forgot to declare that function in your base class declaration (e.g., in CBase.h).

If CBase::CBase() does require one or more arguments then you must correct the problem by including explicit instructions for passing parameters from the derived class constructor function to the base class constructor function. The correction for the example above is:

CDerived::CDerived(int A, int B) : CBase(A) { ... }