MXi4oyu

摘要： class Screen {public:void *operator new( size_t );void *operator new( size_t, Screen* );// ...};额外的参数可以被new 表达式中指定的定位实参初始化例如void func( Screen *start ) {Screen *ps = new (start) Screen;// ...}“new (start) Screen;”这是定位new操作Screen *ps = new (start) Screen;表示在已经开辟好的内存区start中为堆对象Screen申请一个内存也就是说，如果start占 阅读全文