78 lines
2.0 KiB
C#
78 lines
2.0 KiB
C#
//
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// System.Nullable.cs
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//
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// Martin Baulig (martin@ximian.com)
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// Marek Safar (marek.safar@gmail.com)
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//
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// (C) 2004 Novell, Inc.
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//
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//
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// Copyright (C) 2004 Novell, Inc (http://www.novell.com)
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//
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// Permission is hereby granted, free of charge, to any person obtaining
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// a copy of this software and associated documentation files (the
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// "Software"), to deal in the Software without restriction, including
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// without limitation the rights to use, copy, modify, merge, publish,
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// distribute, sublicense, and/or sell copies of the Software, and to
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// permit persons to whom the Software is furnished to do so, subject to
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// the following conditions:
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//
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// The above copyright notice and this permission notice shall be
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// included in all copies or substantial portions of the Software.
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//
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
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// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
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// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
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// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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//
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using System.Reflection;
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using System.Collections.Generic;
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using System.Runtime.CompilerServices;
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using System.Runtime.InteropServices;
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using System.Diagnostics;
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namespace System
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{
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public partial struct Nullable<T> where T: struct
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{
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//
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// These are called by the JIT
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//
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#pragma warning disable 169
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//
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// JIT implementation of box valuetype System.Nullable`1<T>
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//
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static object Box (T? o)
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{
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if (!o.hasValue)
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return null;
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return o.value;
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}
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static T? Unbox (object o)
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{
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if (o == null)
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return null;
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return (T) o;
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}
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static T? UnboxExact (object o)
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{
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if (o == null)
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return null;
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if (o.GetType() != typeof (T))
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throw new InvalidCastException();
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return (T) o;
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}
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#pragma warning restore 169
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}
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}
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