21 #define DECLARE_SINGLE_INSTANCE_BASE(className)       \  argument
23     static className& GetInstance();                  \
25     className(const className&) = delete;             \
26     className& operator=(const className &) = delete; \
27     className(className&&) = delete;                  \
28     className& operator=(className&&) = delete;       \
30 #define DECLARE_SINGLE_INSTANCE(className)  \  argument
31     DECLARE_SINGLE_INSTANCE_BASE(className) \
33     className() = default;                  \
34     ~className() = default;                 \
36 #define IMPLEMENT_SINGLE_INSTANCE(className) \  argument
37 className& className::GetInstance()          \
39     static auto instance = new className();  \