what does __declspec(dllimport) really mean?

Question

I saw the Qt source code like this:

class Q_CORE_EXPORT QBasicAtomicInt
{
public:
...
};

Which Q_CORE_EXPORT macro defines lik

Answer 1

__declspec(dllimport) is a storage-class specifier that tells the compiler that a function or object or data type is defined in an external DLL.

The function or object or data type is exported from a DLL with a corresponding __declspec(dllexport).