mcs/class/corlib/System/Object.cs

   1 //
   2 // System.Object.cs
   3 //
   4 // Author:
   5 //   Miguel de Icaza (miguel@ximian.com)
   6 //
   7 // (C) Ximian, Inc.  http://www.ximian.com
   8 //
   9 //
  10
  11 using System.Runtime.CompilerServices;
  12
  13 namespace System {
  14
  15         public class Object {
  16
  17                 // <summary>
  18                 //   Compares this object to the specified object.
  19                 //   Returns true if they are equal, false otherwise.
  20                 // </summary>
  21                 public virtual bool Equals (object o)
  22                 {
  23                         return this == o;
  24                 }
  25
  26                 // <summary>
  27                 //   Compares two objects for equality
  28                 // </summary>
  29                 public static bool Equals (object a, object b)
  30                 {
  31                         if (a == b)
  32                                 return true;
  33
  34                         if (a == null || b == null)
  35                                 return false;
  36
  37                         return a.Equals (b);
  38                 }
  39
  40                 // <summary>
  41                 //   Initializes a new instance of the object class.
  42                 // </summary>
  43                 public Object ()
  44                 {
  45                 }
  46
  47                 // <summary>
  48                 //   Object destructor.
  49                 // </summary>
  50                 ~Object ()
  51                 {
  52                 }
  53
  54                 // <summary>
  55                 //   Returns a hashcode for this object.  Each derived
  56                 //   class should return a hash code that makes sense
  57                 //   for that particular implementation of the object.
  58                 // </summary>
  59                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
  60                 public extern virtual int GetHashCode ();
  61
  62                 // <summary>
  63                 //   Returns the Type associated with the object.
  64                 // </summary>
  65                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
  66                 public extern Type GetType ();
  67
  68                 // <summary>
  69                 //   Shallow copy of the object.
  70                 // </summary>
  71                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
  72                 protected extern object MemberwiseClone ();
  73
  74                 // <summary>
  75                 //   Returns a stringified representation of the object.
  76                 //   This is not supposed to be used for user presentation,
  77                 //   use Format() for that and IFormattable.
  78                 //
  79                 //   ToString is mostly used for debugging purposes.
  80                 // </summary>
  81                 public virtual string ToString ()
  82                 {
  83                         return GetType().FullName;
  84                 }
  85
  86                 // <summary>
  87                 //   Tests whether a is equal to b.
  88                 //   Can not figure out why this even exists
  89                 // </summary>
  90                 public static bool ReferenceEquals (object a, object b)
  91                 {
  92                         return (a == b);
  93                 }
  94
  95                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
  96                 internal extern IntPtr obj_address ();
  97
  98                 void FieldGetter (string typeName, string fieldName, ref object val)
  99                 {
 100                         /* never called */
 101                 }
 102
 103                 void FieldSetter (string typeName, string fieldName, object val)
 104                 {
 105                         /* never called */
 106                 }
 107         }
 108 }