29.9. Using the -> member access operator

Examine the program below.

 1: using System;
 2:
 3: public class TestClass{
 4:
 5:   public struct Temp{
 6:     public int a;
 7:     public int b;
 8:     public void SaySomething(){
 9:       Console.WriteLine("hi!");
10:     }
11:   }
12:
13:   public unsafe static void Main(){
14:     Temp temp = new Temp();
15:     Temp* pTemp = &temp;
16:
17:     // invoke method of temp by indirection
18:     (*pTemp).SaySomething();
19:
20:     // access field of temp by indirection
21:     Console.WriteLine((*pTemp).a);
22:   }
23: }

Output:

c:expt>
hi!
0

Line 18 invokes a method and line 21 retrieves the value of a field indirectly by applying the indirection operator on the pTemp pointer. C# has a simpler syntax to access a member. Instead of:

(*pTemp).SaySomething();

it uses the -> operator like this:

pTemp->SaySomething();

Similarly, the following two expressions are equivalent:

(*pTemp).a
pTemp->a

The operand on the left of the -> operator must be a pointer type (except void*), and the operand on the right must refer to an accessible member that matches the pointer's referent type.

The -> operator does not add new functionality to unsafe coding, it simply serves to simplify the syntax of potentially intimidating codes. This operator can only be used in an unsafe context.