安全delete，添加refenerce,release

#ifndef SAFE_ADDREF
#define SAFE_ADDREF(p)    if (p != NULL) { p->AddRef(); }
#endif

#ifndef SAFE_RELEASE
#define SAFE_RELEASE(p)    if (p != NULL) { p->Release(); p = NULL; }
#endif

#define SAFE_DELETE(x)                {if ((x)!=NULL) {delete (x); (x)=NULL;}}
#define SAFE_DELETEBUFF(x)            {if((x)!=NULL) {delete [] (x); (x) = NULL;}}

#define SAFE_FREE(x)            {if((x)!=NULL) {free(x); (x) = NULL;}}

int *b = new int[4];
    b[0] = 1;
    b[1] = 2;
    b[2] = 3;
    b[3] = 4;
    b[4] = '\0';

delete[]  b;

b = NULL

char *array = (char*) malloc(sizeof(char) * 5);
    array[0] = 'a';
    array[1] = 'b';
    array[2] = 'c';
    array[3] = 'd';
    array[4] = '\0';

free(array);
    array = NULL;