21 #define DM_DECLARE_SINGLE_INSTANCE_BASE(className)       \  argument
23     static className &GetInstance();                  \
26     className(const className &) = delete;            \
27     className &operator=(const className &) = delete; \
28     className(className &&) = delete;                 \
29     className &operator=(className &&) = delete;
31 #define DM_DECLARE_SINGLE_INSTANCE(className)  \  argument
32     DM_DECLARE_SINGLE_INSTANCE_BASE(className) \
35     className() = default;                  \
36     ~className() = default;
38 #define DM_IMPLEMENT_SINGLE_INSTANCE(className)    \  argument
39     className &className::GetInstance()         \
41         static auto instance = new className(); \