mcs/class/corlib/System/Int32.cs

   1 //
   2 // System.Int32.cs
   3 //
   4 // Author:
   5 //   Miguel de Icaza (miguel@ximian.com)
   6 //
   7 // (C) Ximian, Inc.  http://www.ximian.com
   8 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)
   9 //
  10 // Permission is hereby granted, free of charge, to any person obtaining
  11 // a copy of this software and associated documentation files (the
  12 // "Software"), to deal in the Software without restriction, including
  13 // without limitation the rights to use, copy, modify, merge, publish,
  14 // distribute, sublicense, and/or sell copies of the Software, and to
  15 // permit persons to whom the Software is furnished to do so, subject to
  16 // the following conditions:
  17 //
  18 // The above copyright notice and this permission notice shall be
  19 // included in all copies or substantial portions of the Software.
  20 //
  21 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  22 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  23 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  24 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  25 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  26 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  27 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  28 //
  29
  30 using System.Globalization;
  31 using System.Threading;
  32
  33 namespace System {
  34
  35         [Serializable]
  36         [System.Runtime.InteropServices.ComVisible (true)]
  37         public struct Int32 : IFormattable, IConvertible, IComparable, IComparable<Int32>, IEquatable <Int32>
  38         {
  39
  40                 public const int MaxValue = 0x7fffffff;
  41                 public const int MinValue = -2147483648;
  42
  43                 // This field is looked up by name in the runtime
  44                 internal int m_value;
  45
  46                 public int CompareTo (object value)
  47                 {
  48                         if (value == null)
  49                                 return 1;
  50
  51                         if (!(value is System.Int32))
  52                                 throw new ArgumentException (Locale.GetText ("Value is not a System.Int32"));
  53
  54                         int xv = (int) value;
  55                         if (m_value == xv)
  56                                 return 0;
  57                         if (m_value > xv)
  58                                 return 1;
  59                         else
  60                                 return -1;
  61                 }
  62
  63                 public override bool Equals (object obj)
  64                 {
  65                         if (!(obj is System.Int32))
  66                                 return false;
  67
  68                         return ((int) obj) == m_value;
  69                 }
  70
  71                 public override int GetHashCode ()
  72                 {
  73                         return m_value;
  74                 }
  75
  76                 public int CompareTo (int value)
  77                 {
  78                         if (m_value == value)
  79                                 return 0;
  80                         if (m_value > value)
  81                                 return 1;
  82                         else
  83                                 return -1;
  84                 }
  85
  86                 public bool Equals (int obj)
  87                 {
  88                         return obj == m_value;
  89                 }
  90
  91                 internal static bool ProcessTrailingWhitespace (bool tryParse, string s, int position, ref Exception exc)
  92                 {
  93                         int len = s.Length;
  94
  95                         for (int i = position; i < len; i++){
  96                                 char c = s [i];
  97
  98                                 if (!Char.IsWhiteSpace (c)){
  99                                         if (!tryParse)
 100                                                 exc = GetFormatException ();
 101                                         return false;
 102                                 }
 103                         }
 104                         return true;
 105                 }
 106
 107                 internal static bool Parse (string s, bool tryParse, out int result, out Exception exc)
 108                 {
 109                         int val = 0;
 110                         int len;
 111                         int i, sign = 1;
 112                         bool digits_seen = false;
 113
 114                         result = 0;
 115                         exc = null;
 116
 117                         if (s == null) {
 118                                 if (!tryParse)
 119                                         exc = new ArgumentNullException ("s");
 120                                 return false;
 121                         }
 122
 123                         len = s.Length;
 124
 125                         char c;
 126                         for (i = 0; i < len; i++){
 127                                 c = s [i];
 128                                 if (!Char.IsWhiteSpace (c))
 129                                         break;
 130                         }
 131
 132                         if (i == len) {
 133                                 if (!tryParse)
 134                                         exc = GetFormatException ();
 135                                 return false;
 136                         }
 137
 138                         c = s [i];
 139                         if (c == '+')
 140                                 i++;
 141                         else if (c == '-'){
 142                                 sign = -1;
 143                                 i++;
 144                         }
 145
 146                         for (; i < len; i++){
 147                                 c = s [i];
 148
 149                                 if (c == '\0') {
 150                                         i = len;
 151                                         continue;
 152                                 }
 153
 154                                 if (c >= '0' && c <= '9'){
 155                                         byte d = (byte) (c - '0');
 156
 157                                         if (val > (MaxValue/10))
 158                                                 goto overflow;
 159
 160                                         if (val == (MaxValue/10)){
 161                                                 if ((d > (MaxValue % 10)) && (sign == 1 || (d > ((MaxValue % 10) + 1))))
 162                                                         goto overflow;
 163                                                 if (sign == -1)
 164                                                         val = (val * sign * 10) - d;
 165                                                 else
 166                                                         val = (val * 10) + d;
 167
 168                                                 if (ProcessTrailingWhitespace (tryParse, s, i + 1, ref exc)){
 169                                                         result = val;
 170                                                         return true;
 171                                                 }
 172                                                 goto overflow;
 173                                         } else
 174                                                 val = val * 10 + d;
 175
 176                                         digits_seen = true;
 177                                 } else if (!ProcessTrailingWhitespace (tryParse, s, i, ref exc))
 178                                         return false;
 179                         }
 180                         if (!digits_seen) {
 181                                 if (!tryParse)
 182                                         exc = GetFormatException ();
 183                                 return false;
 184                         }
 185
 186                         if (sign == -1)
 187                                 result = val * sign;
 188                         else
 189                                 result = val;
 190
 191                         return true;
 192
 193                 overflow:
 194                         if (!tryParse)
 195                                 exc = new OverflowException ("Value is too large");
 196                         return false;
 197                 }
 198
 199                 public static int Parse (string s, IFormatProvider provider)
 200                 {
 201                         return Parse (s, NumberStyles.Integer, provider);
 202                 }
 203
 204                 public static int Parse (string s, NumberStyles style)
 205                 {
 206                         return Parse (s, style, null);
 207                 }
 208
 209                 internal static bool CheckStyle (NumberStyles style, bool tryParse, ref Exception exc)
 210                 {
 211                         if ((style & NumberStyles.AllowHexSpecifier) != 0) {
 212                                 NumberStyles ne = style ^ NumberStyles.AllowHexSpecifier;
 213                                 if ((ne & NumberStyles.AllowLeadingWhite) != 0)
 214                                         ne ^= NumberStyles.AllowLeadingWhite;
 215                                 if ((ne & NumberStyles.AllowTrailingWhite) != 0)
 216                                         ne ^= NumberStyles.AllowTrailingWhite;
 217                                 if (ne != 0) {
 218                                         if (!tryParse)
 219                                                 exc = new ArgumentException (
 220                                                         "With AllowHexSpecifier only " +
 221                                                         "AllowLeadingWhite and AllowTrailingWhite " +
 222                                                         "are permitted.");
 223                                         return false;
 224                                 }
 225                         } else if ((uint) style > (uint) NumberStyles.Any){
 226                                 if (!tryParse)
 227                                         exc = new ArgumentException ("Not a valid number style");
 228                                 return false;
 229                         }
 230
 231                         return true;
 232                 }
 233
 234                 internal static bool JumpOverWhite (ref int pos, string s, bool reportError, bool tryParse, ref Exception exc)
 235                 {
 236                         while (pos < s.Length && Char.IsWhiteSpace (s [pos]))
 237                                 pos++;
 238
 239                         if (reportError && pos >= s.Length) {
 240                                 if (!tryParse)
 241                                         exc = GetFormatException ();
 242                                 return false;
 243                         }
 244
 245                         return true;
 246                 }
 247
 248                 internal static void FindSign (ref int pos, string s, NumberFormatInfo nfi,
 249                                       ref bool foundSign, ref bool negative)
 250                 {
 251                         if ((pos + nfi.NegativeSign.Length) <= s.Length &&
 252                                 s.IndexOf (nfi.NegativeSign, pos, nfi.NegativeSign.Length) == pos) {
 253                                 negative = true;
 254                                 foundSign = true;
 255                                 pos += nfi.NegativeSign.Length;
 256                         }
 257                         else if ((pos + nfi.PositiveSign.Length) < s.Length &&
 258                                 s.IndexOf (nfi.PositiveSign, pos, nfi.PositiveSign.Length) == pos) {
 259                                 negative = false;
 260                                 pos += nfi.PositiveSign.Length;
 261                                 foundSign = true;
 262                         }
 263                 }
 264
 265                 internal static void FindCurrency (ref int pos,
 266                                                  string s,
 267                                                  NumberFormatInfo nfi,
 268                                                  ref bool foundCurrency)
 269                 {
 270                         if ((pos + nfi.CurrencySymbol.Length) <= s.Length &&
 271                              s.Substring (pos, nfi.CurrencySymbol.Length) == nfi.CurrencySymbol) {
 272                                 foundCurrency = true;
 273                                 pos += nfi.CurrencySymbol.Length;
 274                         }
 275                 }
 276
 277                 internal static bool FindExponent (ref int pos, string s)
 278                 {
 279                                 int i = s.IndexOfAny(new char [] {'e', 'E'}, pos);
 280                                 if (i < 0)
 281                                                 return false;
 282                                 if (++i == s.Length)
 283                                                 return false;
 284                                 if (s [i] == '+' || s [i] == '-')
 285                                                 if (++i == s.Length)
 286                                                                 return false;
 287                                 if (!Char.IsDigit (s [i]))
 288                                                 return false;
 289                                 for (; i < s.Length; ++i)
 290                                                 if (!Char.IsDigit (s [i]))
 291                                                                 break;
 292                                 pos = i;
 293                                 return true;
 294                 }
 295
 296                 internal static bool FindOther (ref int pos,
 297                                               string s,
 298                                               string other)
 299                 {
 300                         if ((pos + other.Length) <= s.Length &&
 301                              s.Substring (pos, other.Length) == other) {
 302                                 pos += other.Length;
 303                                 return true;
 304                         }
 305
 306                         return false;
 307                 }
 308
 309                 internal static bool ValidDigit (char e, bool allowHex)
 310                 {
 311                         if (allowHex)
 312                                 return Char.IsDigit (e) || (e >= 'A' && e <= 'F') || (e >= 'a' && e <= 'f');
 313
 314                         return Char.IsDigit (e);
 315                 }
 316
 317                 internal static Exception GetFormatException ()
 318                 {
 319                         return new FormatException ("Input string was not in the correct format");
 320                 }
 321
 322                 internal static bool Parse (string s, NumberStyles style, IFormatProvider fp, bool tryParse, out int result, out Exception exc)
 323                 {
 324                         result = 0;
 325                         exc = null;
 326
 327                         if (s == null) {
 328                                 if (!tryParse)
 329                                         exc = new ArgumentNullException ();
 330                                 return false;
 331                         }
 332
 333                         if (s.Length == 0) {
 334                                 if (!tryParse)
 335                                         exc = GetFormatException ();
 336                                 return false;
 337                         }
 338
 339                         NumberFormatInfo nfi = null;
 340                         if (fp != null) {
 341                                 Type typeNFI = typeof (System.Globalization.NumberFormatInfo);
 342                                 nfi = (NumberFormatInfo) fp.GetFormat (typeNFI);
 343                         }
 344                         if (nfi == null)
 345                                 nfi = Thread.CurrentThread.CurrentCulture.NumberFormat;
 346
 347                         if (!CheckStyle (style, tryParse, ref exc))
 348                                 return false;
 349
 350                         bool AllowCurrencySymbol = (style & NumberStyles.AllowCurrencySymbol) != 0;
 351                         bool AllowHexSpecifier = (style & NumberStyles.AllowHexSpecifier) != 0;
 352                         bool AllowThousands = (style & NumberStyles.AllowThousands) != 0;
 353                         bool AllowDecimalPoint = (style & NumberStyles.AllowDecimalPoint) != 0;
 354                         bool AllowParentheses = (style & NumberStyles.AllowParentheses) != 0;
 355                         bool AllowTrailingSign = (style & NumberStyles.AllowTrailingSign) != 0;
 356                         bool AllowLeadingSign = (style & NumberStyles.AllowLeadingSign) != 0;
 357                         bool AllowTrailingWhite = (style & NumberStyles.AllowTrailingWhite) != 0;
 358                         bool AllowLeadingWhite = (style & NumberStyles.AllowLeadingWhite) != 0;
 359                         bool AllowExponent = (style & NumberStyles.AllowExponent) != 0;
 360
 361                         int pos = 0;
 362
 363                         if (AllowLeadingWhite && !JumpOverWhite (ref pos, s, true, tryParse, ref exc))
 364                                 return false;
 365
 366                         bool foundOpenParentheses = false;
 367                         bool negative = false;
 368                         bool foundSign = false;
 369                         bool foundCurrency = false;
 370
 371                         // Pre-number stuff
 372                         if (AllowParentheses && s [pos] == '(') {
 373                                 foundOpenParentheses = true;
 374                                 foundSign = true;
 375                                 negative = true; // MS always make the number negative when there parentheses
 376                                                  // even when NumberFormatInfo.NumberNegativePattern != 0!!!
 377                                 pos++;
 378                                 if (AllowLeadingWhite && !!JumpOverWhite (ref pos, s, true, tryParse, ref exc))
 379                                         return false;
 380
 381                                 if (s.Substring (pos, nfi.NegativeSign.Length) == nfi.NegativeSign) {
 382                                         if (!tryParse)
 383                                                 exc = GetFormatException ();
 384                                         return false;
 385                                 }
 386
 387                                 if (s.Substring (pos, nfi.PositiveSign.Length) == nfi.PositiveSign) {
 388                                         if (!tryParse)
 389                                                 exc = GetFormatException ();
 390                                         return false;
 391                                 }
 392                         }
 393
 394                         if (AllowLeadingSign && !foundSign) {
 395                                 // Sign + Currency
 396                                 FindSign (ref pos, s, nfi, ref foundSign, ref negative);
 397                                 if (foundSign) {
 398                                         if (AllowLeadingWhite && !JumpOverWhite (ref pos, s, true, tryParse, ref exc))
 399                                                 return false;
 400                                         if (AllowCurrencySymbol) {
 401                                                 FindCurrency (ref pos, s, nfi,
 402                                                               ref foundCurrency);
 403                                                 if (foundCurrency && AllowLeadingWhite &&
 404                                                                 !JumpOverWhite (ref pos, s, true, tryParse, ref exc))
 405                                                         return false;
 406                                         }
 407                                 }
 408                         }
 409
 410                         if (AllowCurrencySymbol && !foundCurrency) {
 411                                 // Currency + sign
 412                                 FindCurrency (ref pos, s, nfi, ref foundCurrency);
 413                                 if (foundCurrency) {
 414                                         if (AllowLeadingWhite && !JumpOverWhite (ref pos, s, true, tryParse, ref exc))
 415                                                 return false;
 416                                         if (foundCurrency) {
 417                                                 if (!foundSign && AllowLeadingSign) {
 418                                                         FindSign (ref pos, s, nfi, ref foundSign,
 419                                                                   ref negative);
 420                                                         if (foundSign && AllowLeadingWhite &&
 421                                                                         !JumpOverWhite (ref pos, s, true, tryParse, ref exc))
 422                                                                 return false;
 423                                                 }
 424                                         }
 425                                 }
 426                         }
 427
 428                         int number = 0;
 429                         int nDigits = 0;
 430                         bool decimalPointFound = false;
 431                         int digitValue;
 432                         char hexDigit;
 433
 434                         // Number stuff
 435                         do {
 436
 437                                 if (!ValidDigit (s [pos], AllowHexSpecifier)) {
 438                                         if (AllowThousands &&
 439                                             FindOther (ref pos, s, nfi.NumberGroupSeparator))
 440                                             continue;
 441                                         else
 442                                         if (!decimalPointFound && AllowDecimalPoint &&
 443                                             FindOther (ref pos, s, nfi.NumberDecimalSeparator)) {
 444                                             decimalPointFound = true;
 445                                             continue;
 446                                         }
 447
 448                                         break;
 449                                 }
 450                                 else if (AllowHexSpecifier) {
 451                                         nDigits++;
 452                                         hexDigit = s [pos++];
 453                                         if (Char.IsDigit (hexDigit))
 454                                                 digitValue = (int) (hexDigit - '0');
 455                                         else if (Char.IsLower (hexDigit))
 456                                                 digitValue = (int) (hexDigit - 'a' + 10);
 457                                         else
 458                                                 digitValue = (int) (hexDigit - 'A' + 10);
 459
 460                                         uint unumber = (uint)number;
 461                                         if (tryParse){
 462                                                 if ((unumber & 0xf0000000) != 0)
 463                                                         return false;
 464
 465                                                 number = (int) (unumber * 16u + (uint) digitValue);
 466                                         } else {
 467                                                 number = (int)checked (unumber * 16u + (uint)digitValue);
 468                                         }
 469                                 }
 470                                 else if (decimalPointFound) {
 471                                         nDigits++;
 472                                         // Allows decimal point as long as it's only
 473                                         // followed by zeroes.
 474                                         if (s [pos++] != '0') {
 475                                                 if (!tryParse)
 476                                                         exc = new OverflowException ("Value too large or too " +
 477                                                                         "small.");
 478                                                 return false;
 479                                         }
 480                                 }
 481                                 else {
 482                                         nDigits++;
 483
 484                                         try {
 485                                                 // Calculations done as negative
 486                                                 // (abs (MinValue) > abs (MaxValue))
 487                                                 number = checked (
 488                                                         number * 10 -
 489                                                         (int) (s [pos++] - '0')
 490                                                         );
 491                                         } catch (OverflowException) {
 492                                                 if (!tryParse)
 493                                                         exc = new OverflowException ("Value too large or too " +
 494                                                                         "small.");
 495                                                 return false;
 496                                         }
 497                                 }
 498                         } while (pos < s.Length);
 499
 500                         // Post number stuff
 501                         if (nDigits == 0) {
 502                                 if (!tryParse)
 503                                         exc = GetFormatException ();
 504                                 return false;
 505                         }
 506
 507                         if (AllowExponent)
 508                                         FindExponent(ref pos, s);
 509
 510                         if (AllowTrailingSign && !foundSign) {
 511                                 // Sign + Currency
 512                                 FindSign (ref pos, s, nfi, ref foundSign, ref negative);
 513                                 if (foundSign) {
 514                                         if (AllowTrailingWhite && !JumpOverWhite (ref pos, s, true, tryParse, ref exc))
 515                                                 return false;
 516                                         if (AllowCurrencySymbol)
 517                                                 FindCurrency (ref pos, s, nfi,
 518                                                               ref foundCurrency);
 519                                 }
 520                         }
 521
 522                         if (AllowCurrencySymbol && !foundCurrency) {
 523                                 // Currency + sign
 524                                 FindCurrency (ref pos, s, nfi, ref foundCurrency);
 525                                 if (foundCurrency) {
 526                                         if (AllowTrailingWhite && !JumpOverWhite (ref pos, s, true, tryParse, ref exc))
 527                                                 return false;
 528                                         if (!foundSign && AllowTrailingSign)
 529                                                 FindSign (ref pos, s, nfi, ref foundSign,
 530                                                           ref negative);
 531                                 }
 532                         }
 533
 534                         if (AllowTrailingWhite && pos < s.Length && !JumpOverWhite (ref pos, s, false, tryParse, ref exc))
 535                                 return false;
 536
 537                         if (foundOpenParentheses) {
 538                                 if (pos >= s.Length || s [pos++] != ')') {
 539                                         if (!tryParse)
 540                                                 exc = GetFormatException ();
 541                                         return false;
 542                                 }
 543                                 if (AllowTrailingWhite && pos < s.Length &&
 544                                                 !JumpOverWhite (ref pos, s, false, tryParse, ref exc))
 545                                         return false;
 546                         }
 547
 548                         if (pos < s.Length && s [pos] != '\u0000') {
 549                                 if (!tryParse)
 550                                         exc = GetFormatException ();
 551                                 return false;
 552                         }
 553
 554                         if (!negative && !AllowHexSpecifier){
 555                                 if (tryParse){
 556                                         long lval = -number;
 557
 558                                         if (lval < MinValue || lval > MaxValue)
 559                                                 return false;
 560                                         number = (int) lval;
 561                                 } else
 562                                         number = checked (-number);
 563                         }
 564
 565                         result = number;
 566
 567                         return true;
 568                 }
 569
 570                 public static int Parse (string s)
 571                 {
 572                         Exception exc;
 573                         int res;
 574
 575                         if (!Parse (s, false, out res, out exc))
 576                                 throw exc;
 577
 578                         return res;
 579                 }
 580
 581                 public static int Parse (string s, NumberStyles style, IFormatProvider provider)
 582                 {
 583                         Exception exc;
 584                         int res;
 585
 586                         if (!Parse (s, style, provider, false, out res, out exc))
 587                                 throw exc;
 588
 589                         return res;
 590                 }
 591
 592 #if NET_2_0
 593                 public static bool TryParse (string s, out int result)
 594                 {
 595                         Exception exc;
 596
 597                         if (!Parse (s, true, out result, out exc)) {
 598                                 result = 0;
 599                                 return false;
 600                         }
 601
 602                         return true;
 603                 }
 604
 605                 public static bool TryParse (string s, NumberStyles style, IFormatProvider provider, out int result)
 606                 {
 607                         Exception exc;
 608                         if (!Parse (s, style, provider, true, out result, out exc)) {
 609                                 result = 0;
 610                                 return false;
 611                         }
 612
 613                         return true;
 614                 }
 615 #endif
 616
 617                 public override string ToString ()
 618                 {
 619                         return NumberFormatter.NumberToString (m_value, null);
 620                 }
 621
 622                 public string ToString (IFormatProvider provider)
 623                 {
 624                         return NumberFormatter.NumberToString (m_value, provider);
 625                 }
 626
 627                 public string ToString (string format)
 628                 {
 629                         return ToString (format, null);
 630                 }
 631
 632                 public string ToString (string format, IFormatProvider provider)
 633                 {
 634                         return NumberFormatter.NumberToString (format, m_value, provider);
 635                 }
 636
 637                 // =========== IConvertible Methods =========== //
 638
 639                 public TypeCode GetTypeCode ()
 640                 {
 641                         return TypeCode.Int32;
 642                 }
 643
 644                 bool IConvertible.ToBoolean (IFormatProvider provider)
 645                 {
 646                         return System.Convert.ToBoolean (m_value);
 647                 }
 648
 649                 byte IConvertible.ToByte (IFormatProvider provider)
 650                 {
 651                         return System.Convert.ToByte (m_value);
 652                 }
 653
 654                 char IConvertible.ToChar (IFormatProvider provider)
 655                 {
 656                         return System.Convert.ToChar (m_value);
 657                 }
 658
 659                 DateTime IConvertible.ToDateTime (IFormatProvider provider)
 660                 {
 661                         return System.Convert.ToDateTime (m_value);
 662                 }
 663
 664                 decimal IConvertible.ToDecimal (IFormatProvider provider)
 665                 {
 666                         return System.Convert.ToDecimal (m_value);
 667                 }
 668
 669                 double IConvertible.ToDouble (IFormatProvider provider)
 670                 {
 671                         return System.Convert.ToDouble (m_value);
 672                 }
 673
 674                 short IConvertible.ToInt16 (IFormatProvider provider)
 675                 {
 676                         return System.Convert.ToInt16 (m_value);
 677                 }
 678
 679                 int IConvertible.ToInt32 (IFormatProvider provider)
 680                 {
 681                         return m_value;
 682                 }
 683
 684                 long IConvertible.ToInt64 (IFormatProvider provider)
 685                 {
 686                         return System.Convert.ToInt64 (m_value);
 687                 }
 688
 689                 sbyte IConvertible.ToSByte (IFormatProvider provider)
 690                 {
 691                         return System.Convert.ToSByte (m_value);
 692                 }
 693
 694                 float IConvertible.ToSingle (IFormatProvider provider)
 695                 {
 696                         return System.Convert.ToSingle (m_value);
 697                 }
 698
 699                 object IConvertible.ToType (Type targetType, IFormatProvider provider)
 700                 {
 701                         if (targetType == null)
 702                                 throw new ArgumentNullException ("targetType");
 703                         return System.Convert.ToType (m_value, targetType, provider, false);
 704                 }
 705
 706                 ushort IConvertible.ToUInt16 (IFormatProvider provider)
 707                 {
 708                         return System.Convert.ToUInt16 (m_value);
 709                 }
 710
 711                 uint IConvertible.ToUInt32 (IFormatProvider provider)
 712                 {
 713                         return System.Convert.ToUInt32 (m_value);
 714                 }
 715
 716                 ulong IConvertible.ToUInt64 (IFormatProvider provider)
 717                 {
 718                         return System.Convert.ToUInt64 (m_value);
 719                 }
 720         }
 721 }