简单的ALloctor模板

RT,只能分配固定大小内存的分配器，优点是分配回收只要O（1）

template <typename T>class Alloctor{
private:
    typedef T* address;
    T *memory;
    size_t total_size;
public:
    Alloctor(size_t size = 120) :memory(NULL),total_size(size){
        assert(sizeof(T) >= 4);
        memory = (address)malloc(total_size*sizeof(T));
        void * buf;
        for (size_t  i = 0; i < total_size - 1; i++){
            buf = (void*)(memory + i + 1);
            memcpy(memory + i, &buf,sizeof(void*));
        }
        buf = NULL;
        memcpy(memory+total_size-1,&buf,sizeof(void*));
    }
    address alloc(){
        address res;
        memcpy(&res, memory, sizeof(void*));
        memcpy(memory, res, sizeof(void*));
        return res;
    }
    void free(address a){
        memcpy(a, memory, sizeof(void*));
        void * buf = a;
        memcpy(memory,&buf,sizeof(void*));
    }
    ~Alloctor(){
        free(memory);
    }
};