19行我們overload了<< operator,由於也是global function,所以也要宣告friend。 最後49行和55行的user code,直接用+和*就可以計算複數,而且cout也直接支援Complex物件,非常清楚,這就是operator overloading的威力,不過,在class implementation時,operator overloading的語法不是很好寫,雖然語法很有邏輯很有道理,但就是太臭太長了,還真的得時間熟悉才行。
// overload_date.cpp// compile with: /EHsc#include<iostream>usingnamespacestd;classDate{intmo, da, yr;public: Date(intm,intd,inty) { mo = m; da = d; yr = y; }friendostream&operator<<(ostream& os,constDate& dt); }; ostream&operator<<(ostream& os,constDate& dt) { os << ...
Operator overloading is another feature I could have used but didn’t. Whenever the compiler sees such an operator, it simply replaces it with the appropriate function call. So in the code listing that follows, the last two lines are equivalent and the performance penalty is easily understood...
1)For operator overloading to work, at least one of the operandsmust be a user defined class object. 2)Assignment Operator:Compiler automatically creates a default assignment operator with every class. The default assignment operator does assign all members of right side to the left side and wo...
class base; // as above class middle : private virtual base {}; class top : public virtual middle, private virtual bottom {}; void destroy(top *p) { delete p; } Overloaded operator new and operator delete Previous versions of the compiler allowed non-member operator new and non-member ...
publicclassBase{ }publicclassDerived:Base{ }publicstaticclassIsOperatorExample{publicstaticvoidMain(){objectb =newBase(); Console.WriteLine(bisBase);// output: TrueConsole.WriteLine(bisDerived);// output: Falseobjectd =newDerived(); Console.WriteLine(disBase);// output: TrueConsole.WriteLine(dis...
class-type : 类对象 undefined:不确定 decay:退化 array-to-pointer:数组到指针 inclusion model:包含模型 other type:其他类型 explicit instantiation directive:显示实例化指示符 exporting template:导出模板 separation model:分离模型 precompiled header:预编译头文件 ...
在operator= 中处理 “自我赋值” 赋值对象时应确保复制 “对象内的所有成员变量” 及 “所有 base class 成分”(调用基类复制构造函数) 以对象管理资源(资源在构造函数获得,在析构函数释放,建议使用智能指针,资源取得时机便是初始化时机(Resource Acquisition Is Initialization,RAII)) 在资源管理类中小心 copying 行...
// 类classA{private:constint a;// 常对象成员,只能在初始化列表赋值public:// 构造函数A(){};A(int x):a(x){};// 初始化列表// const可用于对重载函数的区分intgetValue();// 普通成员函数intgetValue()const;// 常成员函数,不得修改类中的任何数据成员的值};voidfunction(){// 对象Ab;// ...
Compiler error C3365operator 'operator': differing operands of type 'type' and 'type' Compiler error C3366'member': static data members of managed/WinRT types must be defined within the class definition Compiler error C3367'function': cannot use static function to create an unbound delegate ...