class/corlib/System/Single.cs

   1 //
   2 // System.Single.cs
   3 //
   4 // Author:
   5 //   Miguel de Icaza (miguel@ximian.com)
   6 //
   7 // (C) Ximian, Inc.  http://www.ximian.com
   8 //
   9
  10 //
  11 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)
  12 //
  13 // Permission is hereby granted, free of charge, to any person obtaining
  14 // a copy of this software and associated documentation files (the
  15 // "Software"), to deal in the Software without restriction, including
  16 // without limitation the rights to use, copy, modify, merge, publish,
  17 // distribute, sublicense, and/or sell copies of the Software, and to
  18 // permit persons to whom the Software is furnished to do so, subject to
  19 // the following conditions:
  20 //
  21 // The above copyright notice and this permission notice shall be
  22 // included in all copies or substantial portions of the Software.
  23 //
  24 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  25 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  26 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  27 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  28 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  29 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  30 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  31 //
  32
  33 using System.Globalization;
  34 using System.Runtime.ConstrainedExecution;
  35
  36 namespace System
  37 {
  38         [Serializable]
  39         [System.Runtime.InteropServices.ComVisible (true)]
  40         public struct Single : IComparable, IFormattable, IConvertible, IComparable <float>, IEquatable <float>
  41         {
  42                 public const float Epsilon = 1.4e-45f;
  43                 public const float MaxValue =  3.40282346638528859e38f;
  44                 public const float MinValue = -3.40282346638528859e38f;
  45                 public const float NaN = 0.0f / 0.0f;
  46                 public const float PositiveInfinity =  1.0f / 0.0f;
  47                 public const float NegativeInfinity = -1.0f / 0.0f;
  48
  49                 // Maximum allowed rounding-error so that float.MaxValue can round-trip successfully; calculated
  50                 // using: (double.Parse (float.MaxValue.ToString ("r")) - (double) float.MaxValue).ToString ("r")
  51                 private const double MaxValueEpsilon = 3.6147112457961776e29d;
  52
  53                 internal float m_value;
  54
  55                 public int CompareTo (object value)
  56                 {
  57                         if (value == null)
  58                                 return 1;
  59
  60                         if (!(value is System.Single))
  61                                 throw new ArgumentException (Locale.GetText ("Value is not a System.Single."));
  62
  63                         float fv = (float)value;
  64
  65                         if (IsPositiveInfinity (m_value) && IsPositiveInfinity (fv))
  66                                 return 0;
  67
  68                         if (IsNegativeInfinity (m_value) && IsNegativeInfinity (fv))
  69                                 return 0;
  70
  71                         if (IsNaN (fv))
  72                                 if (IsNaN (m_value))
  73                                         return 0;
  74                                 else
  75                                         return 1;
  76
  77                         if (IsNaN (m_value))
  78                                 if (IsNaN (fv))
  79                                         return 0;
  80                                 else
  81                                         return -1;
  82
  83                         if (this.m_value == fv)
  84                                 return 0;
  85                         else if (this.m_value > fv)
  86                                 return 1;
  87                         else
  88                                 return -1;
  89                 }
  90
  91                 public override bool Equals (object obj)
  92                 {
  93                         if (!(obj is System.Single))
  94                                 return false;
  95
  96                         float value = (float) obj;
  97
  98                         if (IsNaN (value))
  99                                 return IsNaN (m_value);
 100
 101                         return (value == m_value);
 102                 }
 103
 104                 public int CompareTo (float value)
 105                 {
 106                         if (IsPositiveInfinity (m_value) && IsPositiveInfinity (value))
 107                                 return 0;
 108
 109                         if (IsNegativeInfinity (m_value) && IsNegativeInfinity (value))
 110                                 return 0;
 111
 112                         if (IsNaN (value))
 113                                 if (IsNaN (m_value))
 114                                         return 0;
 115                                 else
 116                                         return 1;
 117
 118                         if (IsNaN (m_value))
 119                                 if (IsNaN (value))
 120                                         return 0;
 121                                 else
 122                                         return -1;
 123
 124                         if (this.m_value == value)
 125                                 return 0;
 126                         else if (this.m_value > value)
 127                                 return 1;
 128                         else
 129                                 return -1;
 130                 }
 131
 132                 public bool Equals (float obj)
 133                 {
 134                         if (IsNaN (obj))
 135                                 return IsNaN (m_value);
 136
 137                         return obj == m_value;
 138                 }
 139
 140                 public unsafe override int GetHashCode ()
 141                 {
 142                         float f = m_value;
 143                         return *((int*)&f);
 144                 }
 145
 146 #if     NET_4_0
 147                 public static bool operator==(float a, float b)
 148                 {
 149                         return a == b;
 150                 }
 151
 152                 public static bool operator!=(float a, float b)
 153                 {
 154                         return a != b;
 155                 }
 156
 157                 public static bool operator>(float a, float b)
 158                 {
 159                         return a > b;
 160                 }
 161
 162                 public static bool operator>=(float a, float b)
 163                 {
 164                         return a >= b;
 165                 }
 166
 167                 public static bool operator<(float a, float b)
 168                 {
 169                         return a < b;
 170                 }
 171
 172                 public static bool operator<=(float a, float b)
 173                 {
 174                         return a <= b;
 175                 }
 176 #endif
 177
 178                 public static bool IsInfinity (float f)
 179                 {
 180                         return (f == PositiveInfinity || f == NegativeInfinity);
 181                 }
 182
 183                 [ReliabilityContractAttribute (Consistency.WillNotCorruptState, Cer.Success)]
 184                 public static bool IsNaN (float f)
 185                 {
 186 #pragma warning disable 1718
 187                         return (f != f);
 188 #pragma warning restore
 189                 }
 190
 191                 public static bool IsNegativeInfinity (float f)
 192                 {
 193                         return (f < 0.0f && (f == NegativeInfinity || f == PositiveInfinity));
 194                 }
 195
 196                 public static bool IsPositiveInfinity (float f)
 197                 {
 198                         return (f > 0.0f && (f == NegativeInfinity || f == PositiveInfinity));
 199                 }
 200
 201                 public static float Parse (string s)
 202                 {
 203                         double parsed_value = Double.Parse (
 204                                 s, (NumberStyles.Float | NumberStyles.AllowThousands), null);
 205                         if (parsed_value - (double) float.MaxValue > MaxValueEpsilon && (!double.IsPositiveInfinity (parsed_value)))
 206                                 throw new OverflowException();
 207
 208                         return (float) parsed_value;
 209                 }
 210
 211                 public static float Parse (string s, IFormatProvider provider)
 212                 {
 213                         double parsed_value = Double.Parse (
 214                                 s, (NumberStyles.Float | NumberStyles.AllowThousands), provider);
 215                         if (parsed_value - (double) float.MaxValue > MaxValueEpsilon && (!double.IsPositiveInfinity (parsed_value)))
 216                                 throw new OverflowException();
 217
 218                         return (float) parsed_value;
 219                 }
 220
 221                 public static float Parse (string s, NumberStyles style)
 222                 {
 223                         double parsed_value = Double.Parse (s, style, null);
 224                         if (parsed_value - (double) float.MaxValue > MaxValueEpsilon && (!double.IsPositiveInfinity (parsed_value)))
 225                                 throw new OverflowException();
 226
 227                         return (float) parsed_value;
 228                 }
 229
 230                 public static float Parse (string s, NumberStyles style, IFormatProvider provider)
 231                 {
 232                         double parsed_value = Double.Parse (s, style, provider);
 233                         if (parsed_value - (double) float.MaxValue > MaxValueEpsilon && (!double.IsPositiveInfinity (parsed_value)))
 234                                 throw new OverflowException();
 235
 236                         return (float) parsed_value;
 237                 }
 238                 public static bool TryParse (string s, NumberStyles style, IFormatProvider provider, out float result)
 239                 {
 240                         double parsed_value;
 241                         Exception exc;
 242                         if (!Double.Parse (s, style, provider, true, out parsed_value, out exc)) {
 243                                 result = 0;
 244                                 return false;
 245                         } else if (parsed_value - (double) float.MaxValue > MaxValueEpsilon && (!double.IsPositiveInfinity (parsed_value))) {
 246                                 result = 0;
 247                                 return false;
 248                         }
 249                         result = (float) parsed_value;
 250                         return true;
 251                 }
 252
 253                 public static bool TryParse (string s, out float result)
 254                 {
 255                         return TryParse (s, NumberStyles.Any, null, out result);
 256                 }
 257
 258                 public override string ToString ()
 259                 {
 260                         return NumberFormatter.NumberToString (m_value, null);
 261                 }
 262
 263                 public string ToString (IFormatProvider provider)
 264                 {
 265                         return NumberFormatter.NumberToString (m_value, provider);
 266                 }
 267
 268                 public string ToString (string format)
 269                 {
 270                         return ToString (format, null);
 271                 }
 272
 273                 public string ToString (string format, IFormatProvider provider)
 274                 {
 275                         return NumberFormatter.NumberToString (format, m_value, provider);
 276                 }
 277
 278                 // ============= IConvertible Methods ============ //
 279                 public TypeCode GetTypeCode ()
 280                 {
 281                         return TypeCode.Single;
 282                 }
 283
 284                 bool IConvertible.ToBoolean (IFormatProvider provider)
 285                 {
 286                         return System.Convert.ToBoolean (m_value);
 287                 }
 288
 289                 byte IConvertible.ToByte (IFormatProvider provider)
 290                 {
 291                         return System.Convert.ToByte (m_value);
 292                 }
 293
 294                 char IConvertible.ToChar (IFormatProvider provider)
 295                 {
 296                         return System.Convert.ToChar (m_value);
 297                 }
 298
 299                 DateTime IConvertible.ToDateTime (IFormatProvider provider)
 300                 {
 301                         return System.Convert.ToDateTime (m_value);
 302                 }
 303
 304                 decimal IConvertible.ToDecimal (IFormatProvider provider)
 305                 {
 306                         return System.Convert.ToDecimal (m_value);
 307                 }
 308
 309                 double IConvertible.ToDouble (IFormatProvider provider)
 310                 {
 311                         return System.Convert.ToDouble (m_value);
 312                 }
 313
 314                 short IConvertible.ToInt16 (IFormatProvider provider)
 315                 {
 316                         return System.Convert.ToInt16 (m_value);
 317                 }
 318
 319                 int IConvertible.ToInt32 (IFormatProvider provider)
 320                 {
 321                         return System.Convert.ToInt32 (m_value);
 322                 }
 323
 324                 long IConvertible.ToInt64 (IFormatProvider provider)
 325                 {
 326                         return System.Convert.ToInt64 (m_value);
 327                 }
 328
 329                 sbyte IConvertible.ToSByte (IFormatProvider provider)
 330                 {
 331                         return System.Convert.ToSByte (m_value);
 332                 }
 333
 334                 float IConvertible.ToSingle (IFormatProvider provider)
 335                 {
 336                         return System.Convert.ToSingle (m_value);
 337                 }
 338
 339                 object IConvertible.ToType (Type targetType, IFormatProvider provider)
 340                 {
 341                         if (targetType == null)
 342                                 throw new ArgumentNullException ("targetType");
 343                         return System.Convert.ToType (m_value, targetType, provider, false);
 344                 }
 345
 346                 ushort IConvertible.ToUInt16 (IFormatProvider provider)
 347                 {
 348                         return System.Convert.ToUInt16 (m_value);
 349                 }
 350
 351                 uint IConvertible.ToUInt32 (IFormatProvider provider)
 352                 {
 353                         return System.Convert.ToUInt32 (m_value);
 354                 }
 355
 356                 ulong IConvertible.ToUInt64 (IFormatProvider provider)
 357                 {
 358                         return System.Convert.ToUInt64 (m_value);
 359                 }
 360         }
 361 }