[Mono-devel-list] Exception in small generic c# program

Martin Willemoes Hansen mwh at sysrq.dk
Wed May 5 17:14:48 EDT 2004


When running the program below I get an exception:

using System;
using System.Collections;

class Hello {

	static void Main()
		MyGenericClass<int> foo = new MyGenericClass<int>();
		foo.Generic = 10;
		Console.WriteLine (foo);

		MyGenericClass<string> bar = 
				new MyGenericClass<string>();
		bar.Generic = "Hello, World!";
		Console.WriteLine (bar);

		MyGenericClass<double> baz = 
				new MyGenericClass<double>();
		baz.Generic = 10.5D;
		Console.WriteLine (baz);

class MyGenericClass<T> {

	T var;

	public T Generic {
		set { var = value; }

	public override string ToString()
		return var.GetType().ToString();


This is the output I get when running the program.
I use Mono Beta1

Unhandled Exception: System.NullReferenceException: A null value was
found where an object instance was required.
in (unmanaged) MyGenericClass!1:ToString ()
in <0x0001d> System.IO.TextWriter:Write (object)
in <0x0000e> System.IO.TextWriter:WriteLine (object)
in <0x00035> System.IO.SynchronizedWriter:WriteLine (object)
in <0x0001a> System.Console:WriteLine (object)
in <0x000d6> Hello:Main ()

Can someone here verify if this a bug?

Martin Willemoes Hansen

E-Mail	mwh at sysrq.dk	Website	mwh.sysrq.dk
IRC     MWH, freenode.net

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