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