下表显示了二元运算符，其目的列表。
| 函数名称 | 运算符 | 目的 |
|---|---|---|
| opBinary | + | 加法 |
| opBinary | - | 减法 |
| opBinary | * | 乘法 |
| opBinary | / | 除法 |
| opBinary | % | 求余 |
| opBinary | ^^ | 幂 |
| opBinary | & | 按位与 |
| opBinary | | | 按位或 |
| opBinary | ^ | 按位异或 |
| opBinary | << | 左移 |
| opBinary | >> | 右移 |
| opBinary | >>> | 逻辑右移 |
| opBinary | ~ | 串连 |
| opBinary | in | 是否包含 |
一个例子如下，解释如何重载一个二元运算符。
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 opBinary(string op)(Box b)
{
if(op == "+")
{
Box box = new Box();
box.length = this.length + b.length;
box.breadth = this.breadth + b.breadth;
box.height = this.height + b.height;
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
Box box3 = new Box(); // Declare Box3 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);
// box 2 specification
box2.setLength(12.0);
box2.setBreadth(13.0);
box2.setHeight(10.0);
// volume of box 1
volume = box1.getVolume();
writeln("Volume of Box1 : ", volume);
// volume of box 2
volume = box2.getVolume();
writeln("Volume of Box2 : ", volume);
// Add two object as follows:
box3 = box1 + box2;
// volume of box 3
volume = box3.getVolume();
writeln("Volume of Box3 : ", volume);
}
让我们编译和运行上面的程序，这将产生以下结果：
Volume of Box1 : 210 Volume of Box2 : 1560 Volume of Box3 : 5400
