What does this c++ class declaration mean?

Question

I saw this piece of code in an article I am reading.

class EXAMPLEUNMANAGEDDLL_API CUnmanagedTestClass
{
public:
    CUnmanagedTestClass();
    virtual ~CUn         


        

Answer 1

Such constructs are used in Windows to control whether the class is being used while building a DLL or it is being used to build a user of the DLL.

When building the DLL, EXAMPLEUNMANAGEDDLL_API needs to expand to __declspec(dllexport).

When buidling users of the DLL, EXAMPLEUNMANAGEDDLL_API needs to expand to __declspec(dllimport).

Further information can be found at:

1. Exporting from a DLL Using __declspec(dllexport)
2. Importing into an Application Using __declspec(dllimport)