int main()
{void *p;str *st;st = (str*)malloc(sizeof(str));st->a = 23;st->b = 24;p = st;//使用void指针需强制类型转换printf("%d\n%d\n",((str*)p)->a, ((str*)p)->b);free(st);map<char, int> mpci;mpci['m'] = 20;mpci.insert(pair<char, int>('r', 30));//插入元素mpci.insert(pair<char,int>('a',40));map<char, int>::iterator iterci;for(iterci = mpci.begin(); iterci != mpci.end(); iterci++)printf("%c:%d ", iterci->first, iterci->second);//已自动排序printf("\n");iterci = mpci.find('r');//查找元素printf("Erase %c:%d\n",iterci->first,iterci->second);mpci.erase(iterci);printf("Erase %c:%d\n", 'a', mpci['a']);mpci.erase('a');if (!mpci.count('a'))//查找有无printf("'a' NULL\n");for (iterci = mpci.begin(); iterci != mpci.end(); iterci++)printf("%c:%d ", iterci->first, iterci->second);//已排序printf("\n");printf("At %c:%d \n", 'm', mpci.at('m'));//取出键对应的值std::cout << "Hello World!\n";
}