47 lines
535 B
C#
47 lines
535 B
C#
using System;
|
|
|
|
struct S
|
|
{
|
|
public int ID { get; set; }
|
|
}
|
|
|
|
class C
|
|
{
|
|
public readonly int ID;
|
|
|
|
private C (int id)
|
|
{
|
|
ID = id;
|
|
}
|
|
|
|
public static explicit operator C (S x)
|
|
{
|
|
throw new ApplicationException ("wrong conversion");
|
|
}
|
|
|
|
public static explicit operator C (S? x)
|
|
{
|
|
return new C (x.HasValue ? x.Value.ID : 5);
|
|
}
|
|
}
|
|
|
|
public class Test
|
|
{
|
|
public static int Main ()
|
|
{
|
|
S? s = null;
|
|
C c = (C) s;
|
|
|
|
if (c.ID != 5)
|
|
return 1;
|
|
|
|
s = new S () { ID = 10 };
|
|
c = (C) s;
|
|
|
|
if (c.ID != 10)
|
|
return 2;
|
|
|
|
return 0;
|
|
}
|
|
}
|