一元運算符重載

下表顯示了一元運算符,其目的列表。

函數名稱

運算符

目的

opUnary

-

負數(數字補)

opUnary

+

相同值(或者,副本)

opUnary

~

按位取反

opUnary

*

訪問指向

opUnary

++

自增

opUnary

--

自減

一個例子如下,解釋如何重載一個二元運算符。

import std.stdio; class Box { public: double getVolume() { return length * breadth * height; } void setLength( double len ) { length = len; } void setBreadth( double bre ) { breadth = bre; } void setHeight( double hei ) { height = hei; } Box opUnary(string op)() { if(op == "++") { Box box = new Box(); box.length = this.length + 1; box.breadth = this.breadth + 1 ; box.height = this.height + 1; return box; } } private: double length; // Length of a box double breadth; // Breadth of a box double height; // Height of a box }; // Main function for the program void main( ) { Box Box1 = new Box(); // Declare Box1 of type Box Box Box2 = new Box(); // Declare Box2 of type Box double volume = 0.0; // Store the volume of a box here // box 1 specification Box1.setLength(6.0); Box1.setBreadth(7.0); Box1.setHeight(5.0); // volume of box 1 volume = Box1.getVolume(); writeln("Volume of Box1 : ", volume); // Add two object as follows: Box2 = ++Box1; // volume of box2 volume = Box2.getVolume(); writeln("Volume of Box2 : ", volume); }

讓我們編譯和運行上面的程序,這將產生以下結果:

Volume of Box1 : 210
Volume of Box2 : 336