21 #define 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 DECLARE_SINGLE_INSTANCE(className)  \  argument
32     DECLARE_SINGLE_INSTANCE_BASE(className) \
35     className() = default;                  \
36     ~className() = default
39 #define IMPLEMENT_SINGLE_INSTANCE(className)    \  argument
40     className &className::GetInstance()         \
42         static auto instance = new className(); \