[Mono-list] Difference in generic IList from .NET

A S adam_misc at yahoo.co.uk
Sat Jan 12 10:42:19 EST 2008

I'm new to mono, and trying to get my existing .NET application to run.  I'm having a problem with a difference in the behavior of generic lists.  Please can someone help me out?  Am I being stupid?  Or should I raise a bug?

In Mono, if a writable list is accessed as an IList, it appears to be treated as readonly.  Here is a minimal program that works fine under .NET:

using System;
using System.Collections.Generic;

namespace MonoTest
  class Program
    static void Main(string[] args)
      IList<int> lList = new int[2];
      lList[0] = 1;

But gives the following exception in mono:

Unhandled Exception: System.NotSupportedException: Collection is read-only
  at System.Array.InternalArray__set_Item[Int32] (Int32 index, Int32 item) [0x00000]
  at (wrapper managed-to-managed) System.Int32[]:System.Collections.Generic.IList`1.set_Item (int,int)
  at MonoTest.Program.Main (System.String[] args) [0x00000]

Many thanks

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