using System;
public class Test
{
public class Base {
}
public class A : Base {
}
public class B : Base {
}
public static void Main() {
A a = new A();
B b = (B)a;
}
}
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prog.cs(15,15): error CS0030: Cannot convert type `Test.A' to `Test.B'
Compilation failed: 1 error(s), 0 warnings