C# 0 The Complete Reference

PART I

C h a p t e r   1 8 :  

G e n e r i c s  

517

PART IPART I

Because of the 

new( )

 constraint, any type argument must supply a parameterless 

constructor.

Next, examine the 

Test

 constructor, shown here:

public Test() {

  // This works because of the new() constraint.

  obj = new T(); // create a T object

}

A new object of type 

T

 is created and a reference to it is assigned to 

obj

. This statement is 

valid only because the 

new( )

 constraint ensures that a constructor will be available. To 

prove this, try removing the 

new( )

 constraint and then attempt to recompile the program. 

As you will see, an error will be reported.

In

Main( )

, an object of type 

Test

 is instantiated, as shown here:

Test x = new Test();

Notice that the type argument is