C# 0 The Complete Reference

true

and

false

 for a class, you enable the compiler to utilize the short-circuit operators without 

having to explicitly overload either. Furthermore, you gain the ability to use objects in 

conditional expressions. In general, unless you need a very narrow implementation of 

&

and

|

, you are better off creating a full implementation.

Conversion Operators

In some situations, you will want to use an object of a class in an expression involving other 

types of data. Sometimes, overloading one or more operators can provide the means of doing 

this. However, in other cases, what you want is a simple type conversion from the class type 

to the target type. To handle these cases, C# allows you to create a special type of 

operator

method called a 

conversion operator.

 A conversion operator converts an object of your class into 

another type. Conversion operators help fully integrate class types into the C# programming 

environment by allowing objects of a class to be freely mixed with other data types as long 

as a conversion to those other types is defined.

There are two forms of conversion operators, implicit and explicit. The general form for 

each is shown here:

public static operator implicit 

target-type

(

source-type v

) { return 

value

; }

public static operator explicit 

target-type

(

source-type v

) { return 

value

; }

Here, 

target-type

 is the target type that you are converting to; 

source-type

 is the type you 

are converting from; and 

value

 is the value of the class after conversion. The conversion 

operators return data of type 

target-type,

 and no other return type specifier is allowed.

If the conversion operator specifies 

implicit

, then the conversion is invoked automatically, 

such as when an object is used in an expression with the target type. When the conversion 

operator specifies 

explicit

, the conversion is invoked when a cast is used. You cannot define 

both an implicit and explicit conversion operator for the same target and source types.

To illustrate a conversion operator, we will create one for the