mcs/class/Microsoft.VisualBasic/Microsoft.VisualBasic/Microsoft.VisualBasic.CompilerServices/DefaultArgumentValueAttribute.cs

   1 //
   2 // Microsoft.VisualBasic.CompilerServices.__DefaultArgumentValueAttribute.cs
   3 //
   4 // Authors:
   5 //   Jambunathan K (kjambunathan@novell.com)
   6 //
   7 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)
   8 //
   9 // Permission is hereby granted, free of charge, to any person obtaining
  10 // a copy of this software and associated documentation files (the
  11 // "Software"), to deal in the Software without restriction, including
  12 // without limitation the rights to use, copy, modify, merge, publish,
  13 // distribute, sublicense, and/or sell copies of the Software, and to
  14 // permit persons to whom the Software is furnished to do so, subject to
  15 // the following conditions:
  16 //
  17 // The above copyright notice and this permission notice shall be
  18 // included in all copies or substantial portions of the Software.
  19 //
  20 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  21 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  22 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  23 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  24 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  25 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  26 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  27 //
  28
  29 using System;
  30
  31 namespace Microsoft.VisualBasic.CompilerServices
  32 {
  33         // Many of the methods of Microsoft.VisualBasic.dll take
  34         // default argument values. The whole of Mono's
  35         // Microsoft.VisualBasic.dll is implemented in C# and C#
  36         // provides no standard constructs that lets a method specify
  37         // default argument values and set appropriate metadata on a
  38         // method parameter.
  39
  40         // This internal attribute:
  41         // Microsoft.VisualBasic.CompilerServices.__DefaultArgumentValueAttribute
  42         // is used to associate a default argument value with a method
  43         // parameter.
  44
  45         // The compiled Microsoft.VisualBasic.dll assembly is then
  46         // post-processed through a "disassemble-fixup-assemble cycle"
  47         // which strips off the "__DefaultArgumentValue" custom
  48         // attribute from the method parameter and replaces it with
  49         // the suitable CIL parameter flags and constants.
  50
  51         [AttributeUsage(AttributeTargets.Parameter)]
  52         internal sealed class __DefaultArgumentValueAttribute : Attribute
  53         {
  54                 private object DefaultArgumentValue;
  55
  56                 public __DefaultArgumentValueAttribute (bool value)
  57                 {
  58                         DefaultArgumentValue = value;
  59                 }
  60
  61                 public __DefaultArgumentValueAttribute (char value)
  62                 {
  63                         DefaultArgumentValue = value;
  64                 }
  65
  66                 public __DefaultArgumentValueAttribute (byte value)
  67                 {
  68                         DefaultArgumentValue = value;
  69                 }
  70
  71                 public __DefaultArgumentValueAttribute (short value)
  72                 {
  73                         DefaultArgumentValue = value;
  74                 }
  75
  76                 public __DefaultArgumentValueAttribute (int value)
  77                 {
  78                         DefaultArgumentValue = value;
  79                 }
  80
  81                 public __DefaultArgumentValueAttribute (long value)
  82                 {
  83                         DefaultArgumentValue = value;
  84                 }
  85
  86                 public __DefaultArgumentValueAttribute (float value)
  87                 {
  88                         DefaultArgumentValue = value;
  89                 }
  90
  91                 public __DefaultArgumentValueAttribute (double value)
  92                 {
  93                         DefaultArgumentValue = value;
  94                 }
  95
  96                 public __DefaultArgumentValueAttribute (string value)
  97                 {
  98                         DefaultArgumentValue = value;
  99                 }
 100
 101                 public __DefaultArgumentValueAttribute (object value)
 102                 {
 103                         DefaultArgumentValue = value;
 104                 }
 105
 106                 public object Value {
 107                         get { return DefaultArgumentValue; }
 108                 }
 109
 110                 public override bool Equals (object obj)
 111                 {
 112                         if (!(obj is __DefaultArgumentValueAttribute))
 113                                 return false;
 114                         if (obj == this)
 115                                 return true;
 116                         return ((__DefaultArgumentValueAttribute) obj).Value == DefaultArgumentValue;
 117                 }
 118
 119                 public override int GetHashCode()
 120                 {
 121                         return DefaultArgumentValue.GetHashCode();
 122                 }
 123         }
 124 }