饿汉模式C++

#define SINGLETON_DEFINE(ClassName)            \
static ClassName* GetInstance()                \
{                                              \
    static ClassName _instance;                \
    return &_instance;                         \
}                                              \
ClassName(const ClassName&) = delete;          \
ClassName& operator=(const ClassName&) = delete

 示例

class Singleton
{
public:
    SINGLETON_DEFINE(Singleton);

private:
    Singleton();
};