Make a copy of the old ZipLib
[mono.git] / mcs / class / corlib / System / String.cs
index df3a144df689db9db0745e19aaddda843b134537..cf66fd4336c54bbf83609e49805bdd51e0a2b6bf 100644 (file)
 // System.String.cs
 //
 // Authors:
-//       Patrik Torstensson (patrik.torstensson@labs2.com)
+//   Patrik Torstensson
 //   Jeffrey Stedfast (fejj@ximian.com)
 //   Dan Lewis (dihlewis@yahoo.co.uk)
+//   Sebastien Pouliot  <sebastien@ximian.com>
 //
 // (C) 2001 Ximian, Inc.  http://www.ximian.com
+// Copyright (C) 2004-2005 Novell (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;
 using System.Text;
 using System.Collections;
 using System.Globalization;
 using System.Runtime.CompilerServices;
 
-namespace System {
-       public sealed class String : IConvertible, IComparable, ICloneable, IEnumerable {
-               private int length;
+#if NET_2_0
+using System.Runtime.ConstrainedExecution;
+using System.Runtime.InteropServices;
+#endif
 
-               public static readonly String Empty = "";
+namespace System
+{
+       [Serializable]
+#if NET_2_0
+       [ComVisible (true)]
+       public sealed class String : IConvertible, ICloneable, IEnumerable, IComparable, IComparable<String>, IEquatable <String>
+#else
+       public sealed class String : IConvertible, ICloneable, IEnumerable, IComparable
+#endif
+       {
+               [NonSerialized] private int length;
+               [NonSerialized] private char start_char;
 
-               [CLSCompliant(false), MethodImplAttribute(MethodImplOptions.InternalCall)]
-               unsafe public extern String(char *value);
+               private const int COMPARE_CASE = 0;
+               private const int COMPARE_INCASE = 1;
+               private const int COMPARE_ORDINAL = 2;
 
-               [CLSCompliant(false), MethodImplAttribute(MethodImplOptions.InternalCall)]
-               unsafe public extern String(char *value, int sindex, int length);
-    
-               [CLSCompliant(false), MethodImplAttribute(MethodImplOptions.InternalCall)]
-               unsafe public extern String(sbyte *value);
+               public static readonly String Empty = "";
 
-               [CLSCompliant(false), MethodImplAttribute(MethodImplOptions.InternalCall)]
-               unsafe public extern String(sbyte *value, int sindex, int length);
+               public static unsafe bool Equals (string a, string b)
+               {
+                       if ((a as object) == (b as object))
+                               return true;
 
-               [CLSCompliant(false), MethodImplAttribute(MethodImplOptions.InternalCall)]
-               unsafe public extern String(sbyte *value, int sindex, int length, Encoding enc);
+                       if (a == null || b == null)
+                               return false;
 
-               [MethodImplAttribute(MethodImplOptions.InternalCall)]
-               public extern String(char [] val, int sindex, int length);
-               
-               [MethodImplAttribute(MethodImplOptions.InternalCall)]
-               public extern String(char [] val);
+                       int len = a.length;
 
-               [MethodImplAttribute(MethodImplOptions.InternalCall)]
-               public extern String(char c, int count);
-       
-               [MethodImplAttribute(MethodImplOptions.InternalCall)]
-               public extern override int GetHashCode();
+                       if (len != b.length)
+                               return false;
 
-               public static bool Equals(String str1, String str2) {
-                       if ((Object) str1 == (Object) str2)
+                       if (len == 0)
                                return true;
-           
-                       if (null == (Object) str1 || null == (Object) str2)
-                               return false;
-                       if (str1.length != str2.length)
-                               return false;
-    
-                       return Compare(str1, 0, str2, 0, str1.length, false) == 0;
-               }
 
-               public static bool operator == (String str1, String str2) {
-                       return Equals(str1, str2);
+                       fixed (char * s1 = &a.start_char, s2 = &b.start_char) {
+                               // it must be one char, because 0 len is done above
+                               if (len < 2)
+                                       return *s1 == *s2;
+
+                               // check by twos
+                               int * sint1 = (int *) s1, sint2 = (int *) s2;
+                               int n2 = len >> 1;
+                               do {
+                                       if (*sint1++ != *sint2++)
+                                               return false;
+                               } while (--n2 != 0);
+
+                               // nothing left
+                               if ((len & 1) == 0)
+                                       return true;
+
+                               // check the last one
+                               return *(char *) sint1 == *(char *) sint2;
+                       }
                }
 
-               public static bool operator != (String str1, String str2) {
-                       return !Equals(str1, str2);
+               public static bool operator == (String a, String b)
+               {
+                       return Equals (a, b);
                }
 
-               public override bool Equals(Object obj) {
-                       if (null == obj)
-                               return false;
-
-                       if (!(obj is String))
-                               return false;
-
-                       return Compare (this, (String)obj, false) == 0;
+               public static bool operator != (String a, String b)
+               {
+                       return !Equals (a, b);
                }
 
-               public bool Equals(String value) {
-                       if (null == value)
-                               return false;
+#if NET_2_0
+               [ReliabilityContractAttribute (Consistency.WillNotCorruptState, Cer.MayFail)]
+#endif
+               public override bool Equals (Object obj)
+               {
+                       return Equals (this, obj as String);
+               }
 
-                       if (length != value.length)
-                               return false;
-                       return Compare (this, 0, value, 0, length, false) == 0;
+#if NET_2_0
+               [ReliabilityContractAttribute (Consistency.WillNotCorruptState, Cer.MayFail)]
+#endif
+               public bool Equals (String value)
+               {
+                       return Equals (this, value);
                }
 
-               [IndexerName("Chars")]
-               public extern char this[int index] {
-                       [MethodImplAttribute(MethodImplOptions.InternalCall)]
+               [IndexerName ("Chars")]
+               public extern char this [int index] {
+                       [MethodImplAttribute (MethodImplOptions.InternalCall)]
                        get;
                }
 
-               public Object Clone() {
+               public Object Clone ()
+               {
                        return this;
                }
 
-               public TypeCode GetTypeCode () {
+               public TypeCode GetTypeCode ()
+               {
                        return TypeCode.String;
                }
 
-               public void CopyTo(int sindex, char[] dest, int dindex, int count) {
+               public void CopyTo (int sourceIndex, char[] destination, int destinationIndex, int count)
+               {
                        // LAMESPEC: should I null-terminate?
-                       
-                       if (dest == null)
-                               throw new ArgumentNullException();
+                       if (destination == null)
+                               throw new ArgumentNullException ("destination");
 
-                       if (sindex < 0 || dindex < 0 || count < 0)
+                       if (sourceIndex < 0 || destinationIndex < 0 || count < 0)
                                throw new ArgumentOutOfRangeException (); 
 
-                       if (sindex + count > Length)
-                               throw new ArgumentOutOfRangeException ();
-
-                       if (dindex + count > dest.Length)
-                               throw new ArgumentOutOfRangeException ();
+                       // re-ordered to avoid possible integer overflow
+                       if (sourceIndex > Length - count)
+                               throw new ArgumentOutOfRangeException ("sourceIndex + count > Length");
+                       // re-ordered to avoid possible integer overflow
+                       if (destinationIndex > destination.Length - count)
+                               throw new ArgumentOutOfRangeException ("destinationIndex + count > destination.Length");
 
-                       InternalCopyTo(sindex, dest, dindex, count);
+                       InternalCopyTo (sourceIndex, destination, destinationIndex, count);
                }
 
-               public char[] ToCharArray() {
-                       return ToCharArray(0, length);
+               public char[] ToCharArray ()
+               {
+                       return ToCharArray (0, length);
                }
 
-               public char[] ToCharArray(int sindex, int length) {
-                       if (sindex < 0 || length < 0 || sindex + length > this.length)
-                               throw new ArgumentOutOfRangeException (); 
+               public char[] ToCharArray (int startIndex, int length)
+               {
+                       if (startIndex < 0)
+                               throw new ArgumentOutOfRangeException ("startIndex", "< 0"); 
+                       if (length < 0)
+                               throw new ArgumentOutOfRangeException ("length", "< 0"); 
+                       // re-ordered to avoid possible integer overflow
+                       if (startIndex > this.length - length)
+                               throw new ArgumentOutOfRangeException ("startIndex + length > this.length"); 
 
-                       char [] tmp = new char[length];
+                       char[] tmp = new char [length];
 
-                       InternalCopyTo(sindex, tmp, 0, length);
+                       InternalCopyTo (startIndex, tmp, 0, length);
 
                        return tmp;
                }
-               
-               public String [] Split(params char [] separator) {
-                       return Split(separator, Int32.MaxValue);
+
+               public String [] Split (params char [] separator)
+               {
+                       return Split (separator, Int32.MaxValue);
                }
 
-               public String[] Split(char[] separator, int count) {
-                       if (null == separator) {
+               public String[] Split (char[] separator, int count)
+               {
+                       if (separator == null || separator.Length == 0)
                                separator = WhiteChars;
-                       }
 
                        if (count < 0)
-                               throw new ArgumentOutOfRangeException ();
+                               throw new ArgumentOutOfRangeException ("count");
 
                        if (count == 0) 
+                               return new String[0];
+
+                       if (count == 1) 
                                return new String[1] { ToString() };
 
-                       return InternalSplit(separator, count);
+                       return InternalSplit (separator, count);
                }
 
-               public String Substring (int sindex) {
-                       if (sindex < 0 || sindex > this.length) {
-                               throw new ArgumentOutOfRangeException();
+#if NET_2_0
+               [ComVisible (false)]
+               [MonoTODO]
+               public String[] Split (char[] separator, int count, StringSplitOptions options)
+               {
+                       if (separator == null || separator.Length == 0)
+                               return Split (WhiteChars, count, options);
+
+                       if (count < 0)
+                               throw new ArgumentOutOfRangeException ("count", "Count cannot be less than zero.");
+                       if ((options != StringSplitOptions.None) && (options != StringSplitOptions.RemoveEmptyEntries))
+                               throw new ArgumentException ("options must be one of the values in the StringSplitOptions enumeration", "options");
+
+                       bool removeEmpty = (options & StringSplitOptions.RemoveEmptyEntries) == StringSplitOptions.RemoveEmptyEntries;
+
+                       if (!removeEmpty)
+                               return Split (separator, count);
+                       else
+                               throw new NotImplementedException ();
+               }
+
+               [ComVisible (false)]
+               public String[] Split (string[] separator, int count, StringSplitOptions options)
+               {
+                       if (separator == null || separator.Length == 0)
+                               return Split (WhiteChars, count, options);
+
+                       if (count < 0)
+                               throw new ArgumentOutOfRangeException ("count", "Count cannot be less than zero.");
+                       if ((options != StringSplitOptions.None) && (options != StringSplitOptions.RemoveEmptyEntries))
+                               throw new ArgumentException ("Illegal enum value: " + options + ".", "options");
+
+                       bool removeEmpty = (options & StringSplitOptions.RemoveEmptyEntries) == StringSplitOptions.RemoveEmptyEntries;
+
+                       if (count == 0 || (this == String.Empty && removeEmpty))
+                               return new String [0];
+
+                       ArrayList arr = new ArrayList ();
+
+                       int pos = 0;
+                       while (pos < this.Length) {
+                               int matchIndex = -1;
+                               int matchPos = Int32.MaxValue;
+
+                               // Find the first position where any of the separators matches
+                               for (int i = 0; i < separator.Length; ++i) {
+                                       string sep = separator [i];
+                                       if (sep == null || sep == String.Empty)
+                                               continue;
+
+                                       int match = IndexOf (sep, pos);
+                                       if (match > -1 && match < matchPos) {
+                                               matchIndex = i;
+                                               matchPos = match;
+                                       }
+                               }
+
+                               if (matchIndex == -1)
+                                       break;
+
+                               if (matchPos == pos && removeEmpty) {
+                                       pos = matchPos + separator [matchIndex].Length;
+                               }
+                               else {
+                                       arr.Add (this.Substring (pos, matchPos - pos));
+
+                                       pos = matchPos + separator [matchIndex].Length;
+
+                                       if (arr.Count == count - 1) {
+                                               break;
+                                       }
+                               }
                        }
 
-                       string tmp = InternalAllocateStr(this.length - sindex);
-                       InternalStrcpy(tmp, 0, this, sindex, length - sindex);
-                       
-                       return tmp;
+                       if (arr.Count == 0)
+                               return new String [] { this };
+                       else {
+                               if (removeEmpty && pos == this.Length) {
+                                       String[] res = new String [arr.Count];
+                                       arr.CopyTo (0, res, 0, arr.Count);
+
+                                       return res;
+                               }
+                               else {
+                                       String[] res = new String [arr.Count + 1];
+                                       arr.CopyTo (0, res, 0, arr.Count);
+                                       res [arr.Count] = this.Substring (pos);
+
+                                       return res;
+                               }
+                       }
                }
 
-               public String Substring (int sindex, int length) {
-                       if (length < 0 || sindex < 0 || sindex + length > this.length) {
-                               throw new ArgumentOutOfRangeException();
+               [ComVisible (false)]
+               public String[] Split (char[] separator, StringSplitOptions options)
+               {
+                       return Split (separator, Int32.MaxValue, options);
+               }
+
+               [ComVisible (false)]
+               public String[] Split (String[] separator, StringSplitOptions options)
+               {
+                       return Split (separator, Int32.MaxValue, options);
+               }
+#endif
+
+               public unsafe String Substring (int startIndex)
+               {
+                       if (startIndex < 0 || startIndex > this.length)
+                               throw new ArgumentOutOfRangeException ("startIndex");
+
+                       int newlen = this.length - startIndex;
+                       string tmp = InternalAllocateStr (newlen);
+                       if (newlen != 0) {
+                               fixed (char *dest = tmp, src = this) {
+                                       memcpy ((byte*)dest, (byte*)(src + startIndex), newlen * 2);
+                               }
                        }
+                       return tmp;
+               }
+
+               public unsafe String Substring (int startIndex, int length)
+               {
+                       if (length < 0)
+                               throw new ArgumentOutOfRangeException ("length", "< 0");
+                       if (startIndex < 0)
+                               throw new ArgumentOutOfRangeException ("startIndex", "< 0");
+                       // re-ordered to avoid possible integer overflow
+                       if (startIndex > this.length - length)
+                               throw new ArgumentOutOfRangeException ("startIndex + length > this.length");
 
                        if (length == 0)
                                return String.Empty;
 
-                       string tmp = InternalAllocateStr(length);
-                       InternalStrcpy(tmp, 0, this, sindex, length);
+                       string tmp = InternalAllocateStr (length);
+                       fixed (char *dest = tmp, src = this) {
+                               memcpy ((byte*)dest, (byte*)(src + startIndex), length * 2);
+                       }
 
                        return tmp;
                }       
 
-               private static readonly char[] WhiteChars = {  (char) 0x9, (char) 0xA, (char) 0xB, (char) 0xC, (char) 0xD, (char) 0x20, (char) 0xA0, (char) 0x2000, (char) 0x2001, (char) 0x2002, (char) 0x2003, (char) 0x2004, (char) 0x2005,
-                                                                                                                                                         (char) 0x2006, (char) 0x2007, (char) 0x2008, (char) 0x2009, (char) 0x200A, (char) 0x200B, (char) 0x3000, (char) 0xFEFF };
+               private static readonly char[] WhiteChars = { (char) 0x9, (char) 0xA, (char) 0xB, (char) 0xC, (char) 0xD,
+#if NET_2_0
+                       (char) 0x85, (char) 0x1680, (char) 0x2028, (char) 0x2029,
+#endif
+                       (char) 0x20, (char) 0xA0, (char) 0x2000, (char) 0x2001, (char) 0x2002, (char) 0x2003, (char) 0x2004,
+                       (char) 0x2005, (char) 0x2006, (char) 0x2007, (char) 0x2008, (char) 0x2009, (char) 0x200A, (char) 0x200B,
+                       (char) 0x3000, (char) 0xFEFF };
 
-               public String Trim(params char[] chars) {
-                       if (null == chars || chars.Length == 0)
-                               chars = WhiteChars;
+               public String Trim ()
+               {
+                       return InternalTrim (WhiteChars, 0);
+               }
 
-                       return InternalTrim(chars, 0);
+               public String Trim (params char[] trimChars)
+               {
+                       if (trimChars == null || trimChars.Length == 0)
+                               trimChars = WhiteChars;
+
+                       return InternalTrim (trimChars, 0);
                }
 
-               public String TrimStart(params char[] chars) {
-                       if (null == chars || chars.Length == 0)
-                               chars = WhiteChars;
+               public String TrimStart (params char[] trimChars)
+               {
+                       if (trimChars == null || trimChars.Length == 0)
+                               trimChars = WhiteChars;
 
-                       return InternalTrim(chars, 1);
+                       return InternalTrim (trimChars, 1);
                }
 
-               public String TrimEnd(params char[] chars) {
-                       if (null == chars || chars.Length == 0)
-                               chars = WhiteChars;
+               public String TrimEnd (params char[] trimChars)
+               {
+                       if (trimChars == null || trimChars.Length == 0)
+                               trimChars = WhiteChars;
 
-                       return InternalTrim(chars, 2);
+                       return InternalTrim (trimChars, 2);
+               }
+
+               public static int Compare (String strA, String strB)
+               {
+                       return Compare (strA, strB, false, CultureInfo.CurrentCulture);
                }
 
-               public static int Compare(String s1, String s2) {
-                       return Compare(s1, s2, false);
+               public static int Compare (String strA, String strB, bool ignoreCase)
+               {
+                       return Compare (strA, strB, ignoreCase, CultureInfo.CurrentCulture);
                }
 
-               public static int Compare(String s1, String s2, bool inCase) {
-                       if (null == s1) {
-                               if (null == s2)
+               public static int Compare (String strA, String strB, bool ignoreCase, CultureInfo culture)
+               {
+                       if (culture == null)
+                               throw new ArgumentNullException ("culture");
+
+                       if (strA == null) {
+                               if (strB == null)
                                        return 0;
                                else
                                        return -1;
-                       } else if (null == s2)
+
+                       }
+                       else if (strB == null) {
                                return 1;
+                       }
+
+                       CompareOptions compopts;
+
+                       if (ignoreCase)
+                               compopts = CompareOptions.IgnoreCase;
+                       else
+                               compopts = CompareOptions.None;
 
-                       return InternalCompare(s1, 0, s2, 0, Math.Max(s1.length, s2.length), inCase);
+                       return culture.CompareInfo.Compare (strA, strB, compopts);
                }
-               
-               [MonoTODO()]
-               public static int Compare(String s1, String s2, bool inCase, CultureInfo culture) {
-                       return Compare(s1, s2, inCase);
+
+               public static int Compare (String strA, int indexA, String strB, int indexB, int length)
+               {
+                       return Compare (strA, indexA, strB, indexB, length, false, CultureInfo.CurrentCulture);
                }
 
-               public static int Compare(String s1, int i1, String s2, int i2, int length) {
-                       return Compare(s1, i1, s2, i2, length, false);
+               public static int Compare (String strA, int indexA, String strB, int indexB, int length, bool ignoreCase)
+               {
+                       return Compare (strA, indexA, strB, indexB, length, ignoreCase, CultureInfo.CurrentCulture);
                }
+               
+               public static int Compare (String strA, int indexA, String strB, int indexB, int length, bool ignoreCase, CultureInfo culture)
+               {
+                       if (culture == null)
+                               throw new ArgumentNullException ("culture");
 
-               public static int Compare(String s1, int i1, String s2, int i2, int length, bool inCase) {
-                       if (null == s1) {
-                               if (null == s2)
+                       if ((indexA > strA.Length) || (indexB > strB.Length) || (indexA < 0) || (indexB < 0) || (length < 0))
+                               throw new ArgumentOutOfRangeException ();
+
+                       if (length == 0)
+                               return 0;
+                       
+                       if (strA == null) {
+                               if (strB == null) {
                                        return 0;
-                               else
+                               } else {
                                        return -1;
-                       } else if (null == s2)
+                               }
+                       }
+                       else if (strB == null) {
                                return 1;
+                       }
 
-                       if (length < 0 || i1 < 0 || i2 < 0)
-                               throw new ArgumentOutOfRangeException ();
+                       CompareOptions compopts;
 
-                       if (i1 > s1.length || i2 > s2.length)
-                               throw new ArgumentOutOfRangeException ();
+                       if (ignoreCase)
+                               compopts = CompareOptions.IgnoreCase;
+                       else
+                               compopts = CompareOptions.None;
 
-                       if (length == 0)
-                               return 0;
+                       /* Need to cap the requested length to the
+                        * length of the string, because
+                        * CompareInfo.Compare will insist that length
+                        * <= (string.Length - offset)
+                        */
+                       int len1 = length;
+                       int len2 = length;
+                       
+                       if (length > (strA.Length - indexA)) {
+                               len1 = strA.Length - indexA;
+                       }
 
-                       return InternalCompare(s1, i1, s2, i2, length, inCase);
-               }
+                       if (length > (strB.Length - indexB)) {
+                               len2 = strB.Length - indexB;
+                       }
 
-               [MonoTODO()]
-               public static int Compare(String s1, int i1, String s2, int i2, int length, bool inCase, CultureInfo culture) {
-                       return Compare(s1, i1, s2, i2, length, inCase);
+                       return culture.CompareInfo.Compare (strA, indexA, len1, strB, indexB, len2, compopts);
                }
 
-               public int CompareTo(Object value) {
-                       if (null == value)
+               public int CompareTo (Object value)
+               {
+                       if (value == null)
                                return 1;
-            
+
                        if (!(value is String))
-                               throw new ArgumentException();
+                               throw new ArgumentException ();
 
-                       return String.Compare(this, (String) value, false);
+                       return String.Compare (this, (String) value, false);
                }
 
-               public int CompareTo(String str) {
-                       if (null == str)
+               public int CompareTo (String strB)
+               {
+                       if (strB == null)
                                return 1;
 
-                       return Compare(this, str, false);
+                       return Compare (this, strB, false);
                }
 
-               public static int CompareOrdinal(String s1, String s2) {
-                       if (null == s1 || null == s2) {
-                               if ((Object)s1 == (Object) s2) {
+               public static int CompareOrdinal (String strA, String strB)
+               {
+                       if (strA == null) {
+                               if (strB == null)
                                        return 0;
-                               }
-
-                               return (s1 == null) ? -1 : 1;
+                               else
+                                       return -1;
+                       }
+                       else if (strB == null) {
+                               return 1;
                        }
 
-                       return InternalCompare(s1, 0, s2, 0, Math.Max(s1.length, s2.length), false);
+                       /* Invariant, because that is cheaper to
+                        * instantiate (and chances are it already has
+                        * been.)
+                        */
+                       return CultureInfo.InvariantCulture.CompareInfo.Compare (strA, strB, CompareOptions.Ordinal);
                }
 
-               public static int CompareOrdinal(String s1, int i1, String s2, int i2, int length) {
-                       if (null == s1 || null == s2) {
-                               if ((Object)s1 == (Object) s2) {
+               public static int CompareOrdinal (String strA, int indexA, String strB, int indexB, int length)
+               {
+                       if ((indexA > strA.Length) || (indexB > strB.Length) || (indexA < 0) || (indexB < 0) || (length < 0))
+                               throw new ArgumentOutOfRangeException ();
+
+                       if (strA == null) {
+                               if (strB == null)
                                        return 0;
-                               }
+                               else
+                                       return -1;
+                       }
+                       else if (strB == null) {
+                               return 1;
+                       }
 
-                               return (s1 == null) ? -1 : 1;
+                       /* Need to cap the requested length to the
+                        * length of the string, because
+                        * CompareInfo.Compare will insist that length
+                        * <= (string.Length - offset)
+                        */
+                       int len1 = length;
+                       int len2 = length;
+
+                       if (length > (strA.Length - indexA)) {
+                               len1 = strA.Length - indexA;
                        }
 
-                       if (i1 < 0 || i2 < 0 || length < 0)
-                               throw new ArgumentOutOfRangeException ();
+                       if (length > (strB.Length - indexB)) {
+                               len2 = strB.Length - indexB;
+                       }
 
-                       if (i1 > s1.length || i2 > s2.length)
-                               throw new ArgumentOutOfRangeException ();
+                       return CultureInfo.InvariantCulture.CompareInfo.Compare (strA, indexA, len1, strB, indexB, len2, CompareOptions.Ordinal);
+               }
 
-                       return InternalCompare(s1, i1, s2, i2, length, false);
+               public bool EndsWith (String value)
+               {
+                       return EndsWith (value, false, CultureInfo.CurrentCulture);
                }
 
-               public bool EndsWith(String value) {
-                       if (null == value)
-                               throw new ArgumentNullException();
+#if NET_2_0
+               public
+#else
+               internal
+#endif
+               bool EndsWith (String value, bool ignoreCase, CultureInfo culture)
+               {
+                       return (culture.CompareInfo.IsSuffix (this, value,
+                               ignoreCase ? CompareOptions.IgnoreCase :
+                               CompareOptions.None));
+               }
 
-                       if (value.length > this.length) {
-                               return false;
-                       }
+               public int IndexOfAny (char [] anyOf)
+               {
+                       if (anyOf == null)
+                               throw new ArgumentNullException ("anyOf");
 
-                       return (0 == Compare(this, length - value.length, value, 0, value.length));
+                       return InternalIndexOfAny (anyOf, 0, this.length);
                }
-       
-               public int IndexOfAny(char [] arr) {
-                       if (null == arr)
-                               throw new ArgumentNullException();
 
-                       return InternalIndexOfAny(arr, 0, this.length);
+               public int IndexOfAny (char [] anyOf, int startIndex)
+               {
+                       if (anyOf == null)
+                               throw new ArgumentNullException ("anyOf");
+                       if (startIndex < 0 || startIndex > this.length)
+                               throw new ArgumentOutOfRangeException ("startIndex");
+
+                       return InternalIndexOfAny (anyOf, startIndex, this.length - startIndex);
                }
 
-               public int IndexOfAny(char [] arr, int sindex) {
-                       if (null == arr)
-                               throw new ArgumentNullException();
-                       if (sindex < 0 || sindex >= this.length)
-                               throw new ArgumentOutOfRangeException();
+               public int IndexOfAny (char [] anyOf, int startIndex, int count)
+               {
+                       if (anyOf == null)
+                               throw new ArgumentNullException ("anyOf");
+                       if (startIndex < 0)
+                               throw new ArgumentOutOfRangeException ("startIndex", "< 0");
+                       if (count < 0)
+                               throw new ArgumentOutOfRangeException ("count", "< 0");
+                       // re-ordered to avoid possible integer overflow
+                       if (startIndex > this.length - count)
+                               throw new ArgumentOutOfRangeException ("startIndex + count > this.length");
 
-                       return InternalIndexOfAny(arr, sindex, this.length - sindex);
+                       return InternalIndexOfAny (anyOf, startIndex, count);
                }
 
-               public int IndexOfAny(char [] arr, int sindex, int count) {
-                       if (null == arr)
-                               throw new ArgumentNullException();
-                       if (sindex < 0 || count < 0 || sindex + count > this.length)
-                               throw new ArgumentOutOfRangeException ();
+               public int IndexOf (char value)
+               {
+                       return IndexOf (value, 0, this.length);
+               }
 
-                       return InternalIndexOfAny(arr, sindex, count);
+               public int IndexOf (String value)
+               {
+                       return IndexOf (value, 0, this.length);
                }
 
-               public int IndexOf(char value) {
-                       return InternalIndexOf(value, 0, this.length);
+               public int IndexOf (char value, int startIndex)
+               {
+                       return IndexOf (value, startIndex, this.length - startIndex);
                }
 
-               public int IndexOf(String value) {
-                       return IndexOf(value, 0, this.length);
+               public int IndexOf (String value, int startIndex)
+               {
+                       return IndexOf (value, startIndex, this.length - startIndex);
                }
 
-               public int IndexOf(char value, int sindex) {
-                       if (sindex < 0 || sindex >= this.length) {
-                               throw new ArgumentOutOfRangeException();
-                       }
+               /* This method is culture-insensitive */
+               public int IndexOf (char value, int startIndex, int count)
+               {
+                       if (startIndex < 0)
+                               throw new ArgumentOutOfRangeException ("startIndex", "< 0");
+                       if (count < 0)
+                               throw new ArgumentOutOfRangeException ("count", "< 0");
+                       // re-ordered to avoid possible integer overflow
+                       if (startIndex > this.length - count)
+                               throw new ArgumentOutOfRangeException ("startIndex + count > this.length");
 
-                       return InternalIndexOf(value, sindex, this.length - sindex);
-               }
+                       if ((startIndex == 0 && this.length == 0) || (startIndex == this.length) || (count == 0))
+                               return -1;
 
-               public int IndexOf(String value, int sindex) {
-                       return IndexOf(value, sindex, this.length - sindex);
+                       for (int pos = startIndex; pos < startIndex + count; pos++) {
+                               if (this[pos] == value)
+                                       return(pos);
+                       }
+                       return -1;
                }
 
-               public int IndexOf(char value, int sindex, int count) {
-                       if (sindex < 0 || count < 0 || sindex + count > this.length)
-                               throw new ArgumentOutOfRangeException ();
-                       
-                       if (sindex == 0 && this.length == 0)
-                               return -1;                      
+               /* But this one is culture-sensitive */
+               public int IndexOf (String value, int startIndex, int count)
+               {
+                       if (value == null)
+                               throw new ArgumentNullException ("value");
+                       if (startIndex < 0)
+                               throw new ArgumentOutOfRangeException ("startIndex", "< 0");
+                       if (count < 0)
+                               throw new ArgumentOutOfRangeException ("count", "< 0");
+                       // re-ordered to avoid possible integer overflow
+                       if (startIndex > this.length - count)
+                               throw new ArgumentOutOfRangeException ("startIndex + count > this.length");
 
-                       return InternalIndexOf(value, sindex, count);
-               }
-               
-               public int IndexOf(String value, int sindex, int count) {
-                       if (null == value) 
-                               throw new ArgumentNullException();
+                       if (value.length == 0)
+                               return startIndex;
 
-                       if (sindex < 0 || count < 0 || sindex + count > this.length)
-                               throw new ArgumentOutOfRangeException ();
-                       
-                       if (sindex == 0 && this.length == 0)
-                               return -1;                      
+                       if (startIndex == 0 && this.length == 0)
+                               return -1;
 
-                       return InternalIndexOf(value, sindex, count);
+                       if (count == 0)
+                               return -1;
+
+                       return CultureInfo.CurrentCulture.CompareInfo.IndexOf (this, value, startIndex, count);
                }
 
-               public int LastIndexOfAny(char [] arr) {
-                       if (null == arr) 
-                               throw new ArgumentNullException();
+               public int LastIndexOfAny (char [] anyOf)
+               {
+                       if (anyOf == null)
+                               throw new ArgumentNullException ("anyOf");
 
-                       return InternalLastIndexOfAny(arr, this.length - 1, this.length);
+                       return InternalLastIndexOfAny (anyOf, this.length - 1, this.length);
                }
 
-               public int LastIndexOfAny(char [] arr, int sindex) {
-                       if (null == arr) 
-                               throw new ArgumentNullException();
+               public int LastIndexOfAny (char [] anyOf, int startIndex)
+               {
+                       if (anyOf == null) 
+                               throw new ArgumentNullException ("anyOf");
 
-                       if (sindex < 0 || sindex > this.length)
-                               throw new ArgumentOutOfRangeException();
+                       if (startIndex < 0 || startIndex >= this.length)
+                               throw new ArgumentOutOfRangeException ();
 
                        if (this.length == 0)
                                return -1;
 
-                       return InternalLastIndexOfAny(arr, sindex, sindex + 1);
+                       return InternalLastIndexOfAny (anyOf, startIndex, startIndex + 1);
                }
 
-               public int LastIndexOfAny(char [] arr, int sindex, int count) {
-                       if (null == arr) 
-                               throw new ArgumentNullException();
+               public int LastIndexOfAny (char [] anyOf, int startIndex, int count)
+               {
+                       if (anyOf == null) 
+                               throw new ArgumentNullException ("anyOf");
 
-                       if (sindex < 0 || count < 0 || sindex > this.length || sindex - count < -1)
-                               throw new ArgumentOutOfRangeException();
+                       if ((startIndex < 0) || (startIndex >= this.Length))
+                               throw new ArgumentOutOfRangeException ("startIndex", "< 0 || > this.Length");
+                       if ((count < 0) || (count > this.Length))
+                               throw new ArgumentOutOfRangeException ("count", "< 0 || > this.Length");
+                       if (startIndex - count + 1 < 0)
+                               throw new ArgumentOutOfRangeException ("startIndex - count + 1 < 0");
 
                        if (this.length == 0)
                                return -1;
 
-                       return InternalLastIndexOfAny(arr, sindex, count);
+                       return InternalLastIndexOfAny (anyOf, startIndex, count);
                }
 
-               public int LastIndexOf(char value) {
-                       return InternalLastIndexOf(value, this.length - 1, this.length);
+               public int LastIndexOf (char value)
+               {
+                       if (this.length == 0)
+                               return -1;
+                       else
+                               return LastIndexOf (value, this.length - 1, this.length);
                }
 
-               public int LastIndexOf(String value) {
-                       if (null == value) 
-                               throw new ArgumentNullException();
-
-                       return InternalLastIndexOf(value, this.length - 1, this.length);
+               public int LastIndexOf (String value)
+               {
+                       if (this.length == 0)
+                               /* This overload does additional checking */
+                               return LastIndexOf (value, 0, 0);
+                       else
+                               return LastIndexOf (value, this.length - 1, this.length);
                }
 
-               public int LastIndexOf(char value, int sindex){
-                       return LastIndexOf(value, sindex, sindex + 1);
+               public int LastIndexOf (char value, int startIndex)
+               {
+                       return LastIndexOf (value, startIndex, startIndex + 1);
                }
 
-               public int LastIndexOf(String value, int sindex) {
-                       return LastIndexOf(value, sindex, sindex + 1);
+               public int LastIndexOf (String value, int startIndex)
+               {
+                       if (value == null)
+                               throw new ArgumentNullException ("value");
+                       int max = startIndex;
+                       if (max < this.Length)
+                               max++;
+                       return LastIndexOf (value, startIndex, max);
                }
 
-               public int LastIndexOf(char value, int sindex, int count) {
-                       if (count < 0 || sindex < 0)
-                               throw new ArgumentOutOfRangeException ();
-
-                       if (count > this.length || sindex > this.length)
-                               throw new ArgumentOutOfRangeException ();
-
-                       if (sindex == 0 && this.length == 0)
+               /* This method is culture-insensitive */
+               public int LastIndexOf (char value, int startIndex, int count)
+               {
+                       if (startIndex == 0 && this.length == 0)
                                return -1;
 
-                       return InternalLastIndexOf(value, sindex, count);
+                       // >= for char (> for string)
+                       if ((startIndex < 0) || (startIndex >= this.Length))
+                               throw new ArgumentOutOfRangeException ("startIndex", "< 0 || >= this.Length");
+                       if ((count < 0) || (count > this.Length))
+                               throw new ArgumentOutOfRangeException ("count", "< 0 || > this.Length");
+                       if (startIndex - count + 1 < 0)
+                               throw new ArgumentOutOfRangeException ("startIndex - count + 1 < 0");
+
+                       for(int pos = startIndex; pos > startIndex - count; pos--) {
+                               if (this [pos] == value)
+                                       return pos;
+                       }
+                       return -1;
                }
 
-               public int LastIndexOf(String value, int sindex, int count) {
-                       if (null == value) 
-                               throw new ArgumentNullException();
+               /* But this one is culture-sensitive */
+               public int LastIndexOf (String value, int startIndex, int count)
+               {
+                       if (value == null)
+                               throw new ArgumentNullException ("value");
+                       // -1 > startIndex > for string (0 > startIndex >= for char)
+                       if ((startIndex < -1) || (startIndex > this.Length))
+                               throw new ArgumentOutOfRangeException ("startIndex", "< 0 || > this.Length");
+                       if ((count < 0) || (count > this.Length))
+                               throw new ArgumentOutOfRangeException ("count", "< 0 || > this.Length");
+                       if (startIndex - count + 1 < 0)
+                               throw new ArgumentOutOfRangeException ("startIndex - count + 1 < 0");
+
+                       if (value.Length == 0)
+                               return 0;
 
-                       if (sindex < 0 || sindex > this.length)
-                               throw new ArgumentOutOfRangeException ();
+                       if (startIndex == 0 && this.length == 0)
+                               return -1;
 
-                       if (count < 0 || count - sindex <= 0)
-                               throw new ArgumentOutOfRangeException ();
+                       // This check is needed to match undocumented MS behaviour
+                       if (this.length == 0 && value.length > 0)
+                               return -1;
+
+                       if (value.length > startIndex)
+                               return -1;
 
-                       if (sindex == 0 && this.length == 0)
+                       if (count == 0)
                                return -1;
 
-                       return InternalLastIndexOf(value, sindex, count);
+                       if (startIndex == this.Length)
+                               startIndex--;
+                       return CultureInfo.CurrentCulture.CompareInfo.LastIndexOf (this, value, startIndex, count);
                }
 
-               public String PadLeft(int width) {
-                       return PadLeft(width, ' ');
+#if NET_2_0
+               public bool Contains (String value)
+               {
+                       return IndexOf (value) != -1;
                }
 
-               public String PadLeft(int width, char chr) {
-                       if (width < 0)
-                               throw new ArgumentException();
+               public static bool IsNullOrEmpty (String value)
+               {
+                       return (value == null) || (value.Length == 0);
+               }
 
-                       if (width < this.length)
-                               return String.Copy(this);
+               public string Remove (int startIndex)
+               {
+                       if (startIndex < 0)
+                               throw new ArgumentOutOfRangeException ("startIndex", "StartIndex can not be less than zero");
+                       if (startIndex >= this.length)
+                               throw new ArgumentOutOfRangeException ("startIndex", "StartIndex must be less than the length of the string");
 
-                       return InternalPad(width, chr, false);
+                       return Remove (startIndex, this.length - startIndex);
                }
+#endif
 
-               public String PadRight(int width) {
-                       return PadRight(width, ' ');
+               public String PadLeft (int totalWidth)
+               {
+                       return PadLeft (totalWidth, ' ');
                }
 
-               public String PadRight(int width, char chr) {
-                       if (width < 0)
-                               throw new ArgumentException();
+               public String PadLeft (int totalWidth, char paddingChar)
+               {
+                       if (totalWidth < 0)
+                               throw new ArgumentOutOfRangeException ("totalWidth", "< 0");
 
-                       if (width < this.length)
-                               return String.Copy(this);
+                       if (totalWidth < this.length)
+                               return String.Copy (this);
 
-                       return InternalPad(width, chr, true);
+                       return InternalPad (totalWidth, paddingChar, false);
                }
 
-               public bool StartsWith(String value) {
-                       if (null == value)
-                               throw new ArgumentNullException();
+               public String PadRight (int totalWidth)
+               {
+                       return PadRight (totalWidth, ' ');
+               }
 
-                       if (this.length < value.length)
-                               return false;
+               public String PadRight (int totalWidth, char paddingChar)
+               {
+                       if (totalWidth < 0)
+                               throw new ArgumentOutOfRangeException ("totalWidth", "< 0");
+
+                       if (totalWidth < this.length)
+                               return String.Copy (this);
 
-                       return (0 == Compare(this, 0, value, 0 , value.length));
+                       return InternalPad (totalWidth, paddingChar, true);
                }
-       
-    
-               public String Replace (char oldChar, char newChar) {
-                       return InternalReplace(oldChar, newChar);
+
+               public bool StartsWith (String value)
+               {
+                       return StartsWith (value, false, CultureInfo.CurrentCulture);
                }
 
-               public String Replace(String oldValue, String newValue) {
-                       if (null == oldValue)
-                               throw new ArgumentNullException();
+#if NET_2_0
+               public
+#else
+               internal
+#endif
+               bool StartsWith (String value, bool ignoreCase, CultureInfo culture)
+               {
+                       return (culture.CompareInfo.IsPrefix (this, value,
+                               ignoreCase ? CompareOptions.IgnoreCase :
+                               CompareOptions.None));
+               }
 
-                       return InternalReplace(oldValue, newValue);
+               /* This method is culture insensitive */
+               public String Replace (char oldChar, char newChar)
+               {
+                       return InternalReplace (oldChar, newChar);
                }
 
-               public String Remove(int sindex, int count) {
-                       if (sindex < 0 || count < 0 || sindex + count > this.length)
-                               throw new ArgumentOutOfRangeException ();
+               /* This method is culture sensitive */
+               public String Replace (String oldValue, String newValue)
+               {
+                       if (oldValue == null)
+                               throw new ArgumentNullException ("oldValue");
 
-                       return InternalRemove(sindex, count);
+                       if (oldValue.Length == 0)
+                               throw new ArgumentException ("oldValue is the empty string.");
+
+                       if (this.Length == 0)
+                               return this;
+                       
+                       if (newValue == null)
+                               newValue = String.Empty;
+
+                       return InternalReplace (oldValue, newValue, CultureInfo.CurrentCulture.CompareInfo);
+               }
+
+               public unsafe String Remove (int startIndex, int count)
+               {
+                       if (startIndex < 0)
+                               throw new ArgumentOutOfRangeException ("startIndex", "< 0");
+                       if (count < 0)
+                               throw new ArgumentOutOfRangeException ("count", "< 0");
+                       // re-ordered to avoid possible integer overflow
+                       if (startIndex > this.length - count)
+                               throw new ArgumentOutOfRangeException ("startIndex + count > this.length");
+
+                       String tmp = InternalAllocateStr (this.length - count);
+
+                       fixed (char *dest = tmp, src = this) {
+                               char *dst = dest;
+                               memcpy ((byte*)dst, (byte*)src, startIndex * 2);
+                               int skip = startIndex + count;
+                               dst += startIndex;
+                               memcpy ((byte*)dst, (byte*)(src + skip), (length - skip) * 2);
+                       }
+                       return tmp;
                }
 
-               public String ToLower() {
-                       return InternalToLower();
+               public String ToLower ()
+               {
+                       return ToLower (CultureInfo.CurrentCulture);
                }
 
-               public String ToLower(CultureInfo culture) {
-                       throw new NotImplementedException();
+               public String ToLower (CultureInfo culture)
+               {
+                       if (culture == null)
+                               throw new ArgumentNullException ("culture");
+
+                       if (culture.LCID == 0x007F) { // Invariant
+                               return ToLowerInvariant ();
+                       }
+                       return culture.TextInfo.ToLower (this);
                }
 
-               public String ToUpper() {
-                       return InternalToUpper();
+#if NET_2_0
+               public unsafe String ToLowerInvariant ()
+#else
+               internal unsafe String ToLowerInvariant ()
+#endif
+               {
+                       string tmp = InternalAllocateStr (length);
+                       fixed (char* source = &start_char, dest = tmp) {
+
+                               char* destPtr = (char*)dest;
+                               char* sourcePtr = (char*)source;
+
+                               for (int n = 0; n < length; n++) {
+                                       *destPtr = Char.ToLowerInvariant (*sourcePtr);
+                                       sourcePtr++;
+                                       destPtr++;
+                               }
+                       }
+                       return tmp;
                }
 
-               public String ToUpper(CultureInfo culture) {
-                       throw new NotImplementedException();
+               public String ToUpper ()
+               {
+                       return ToUpper (CultureInfo.CurrentCulture);
                }
 
-               public override String ToString() {
-                       return this;
+               public String ToUpper (CultureInfo culture)
+               {
+                       if (culture == null)
+                               throw new ArgumentNullException ("culture");
+
+                       if (culture.LCID == 0x007F) { // Invariant
+                               return ToUpperInvariant ();
+                       }
+                       return culture.TextInfo.ToUpper (this);
                }
 
-               public String ToString(IFormatProvider provider) {
+#if NET_2_0
+               public unsafe String ToUpperInvariant ()
+#else
+               internal unsafe String ToUpperInvariant ()
+#endif
+               {
+                       string tmp = InternalAllocateStr (length);
+                       fixed (char* source = &start_char, dest = tmp) {
+
+                               char* destPtr = (char*)dest;
+                               char* sourcePtr = (char*)source;
+
+                               for (int n = 0; n < length; n++) {
+                                       *destPtr = Char.ToUpperInvariant (*sourcePtr);
+                                       sourcePtr++;
+                                       destPtr++;
+                               }
+                       }
+                       return tmp;
+               }
+
+               public override String ToString ()
+               {
                        return this;
                }
 
-               public String Trim() {
-                       return Trim(null);
+               public String ToString (IFormatProvider provider)
+               {
+                       return this;
                }
 
-               public static String Format(String format, Object arg0) {
-                       return Format(null, format, new Object[] {arg0});
+               public static String Format (String format, Object arg0)
+               {
+                       return Format (null, format, new Object[] {arg0});
                }
 
-               public static String Format(String format, Object arg0, Object arg1) {
-                       return Format(null, format, new Object[] {arg0, arg1});
+               public static String Format (String format, Object arg0, Object arg1)
+               {
+                       return Format (null, format, new Object[] {arg0, arg1});
                }
 
-               public static String Format(String format, Object arg0, Object arg1, Object arg2) {
-                       return Format(null, format, new Object[] {arg0, arg1, arg2});
+               public static String Format (String format, Object arg0, Object arg1, Object arg2)
+               {
+                       return Format (null, format, new Object[] {arg0, arg1, arg2});
                }
 
-               public static string Format (string format, params object[] args) {
+               public static string Format (string format, params object[] args)
+               {
                        return Format (null, format, args);
                }
        
-               public static string Format (IFormatProvider provider, string format, params object[] args) {
+               public static string Format (IFormatProvider provider, string format, params object[] args)
+               {
+                       StringBuilder b = new StringBuilder ();
+                       FormatHelper (b, provider, format, args);
+                       return b.ToString ();
+               }
+               
+               internal static void FormatHelper (StringBuilder result, IFormatProvider provider, string format, params object[] args)
+               {
                        if (format == null || args == null)
                                throw new ArgumentNullException ();
-               
-                       StringBuilder result = new StringBuilder ();
 
                        int ptr = 0;
                        int start = ptr;
@@ -606,14 +1063,15 @@ namespace System {
                                        // pad formatted string and append to result
 
                                        if (width > str.length) {
-                                               string pad = new String (' ', width - str.length);
+                                               const char padchar = ' ';
+                                               int padlen = width - str.length;
 
                                                if (left_align) {
                                                        result.Append (str);
-                                                       result.Append (pad);
+                                                       result.Append (padchar, padlen);
                                                }
                                                else {
-                                                       result.Append (pad);
+                                                       result.Append (padchar, padlen);
                                                        result.Append (str);
                                                }
                                        }
@@ -622,297 +1080,435 @@ namespace System {
 
                                        start = ptr;
                                }
-                               else if (c == '}' && format[ptr] == '}') {
+                               else if (c == '}' && ptr < format.length && format[ptr] == '}') {
                                        result.Append (format, start, ptr - start - 1);
                                        start = ptr ++;
                                }
+                               else if (c == '}') {
+                                       throw new FormatException ("Input string was not in a correct format.");
+                               }
                        }
 
                        if (start < format.length)
-                               result.Append (format.Substring (start));
-
-                       return result.ToString ();
+                               result.Append (format, start, format.Length - start);
                }
 
-               public static String Copy (String str) {
+               public unsafe static String Copy (String str)
+               {
                        if (str == null)
-                               throw new ArgumentNullException ();
+                               throw new ArgumentNullException ("str");
 
                        int length = str.length;
 
-                       String tmp = InternalAllocateStr(length);
-                       InternalStrcpy(tmp, 0, str);
+                       String tmp = InternalAllocateStr (length);
+                       if (length != 0) {
+                               fixed (char *dest = tmp, src = str) {
+                                       memcpy ((byte*)dest, (byte*)src, length * 2);
+                               }
+                       }
                        return tmp;
                }
 
-               public static String Concat(Object obj) {
-                       if (null == obj)
+               public static String Concat (Object obj)
+               {
+                       if (obj == null)
                                return String.Empty;
 
-                       return obj.ToString();
+                       return obj.ToString ();
                }
 
-               public static String Concat(Object obj1, Object obj2) {
-                       if (null == obj1)
-                               obj1 = String.Empty;
-    
-                       if (null == obj2)
-                               obj2 = String.Empty;
+               public unsafe static String Concat (Object obj1, Object obj2)
+               {
+                       string s1, s2;
+
+                       s1 = (obj1 != null) ? obj1.ToString () : null;
+                       s2 = (obj2 != null) ? obj2.ToString () : null;
+                       
+                       if (s1 == null) {
+                               if (s2 == null)
+                                       return String.Empty;
+                               else
+                                       return s2;
+                       } else if (s2 == null)
+                               return s1;
+
+                       String tmp = InternalAllocateStr (s1.Length + s2.Length);
+                       if (s1.Length != 0) {
+                               fixed (char *dest = tmp, src = s1) {
+                                       memcpy ((byte*)dest, (byte*)src, s1.length * 2);
+                               }
+                       }
+                       if (s2.Length != 0) {
+                               fixed (char *dest = tmp, src = s2) {
+                                       memcpy ((byte*)(dest + s1.Length), (byte*)src, s2.length * 2);
+                               }
+                       }
 
-                       return Concat(obj1.ToString(), obj2.ToString());
+                       return tmp;
                }
 
-               public static String Concat(Object obj1, Object obj2, Object obj3) {
-                       if (null == obj1)
-                               obj1 = String.Empty;
-    
-                       if (null == obj2)
-                               obj2 = String.Empty;
-    
-                       if (null == obj3)
-                               obj3 = String.Empty;
-    
-                       return Concat(obj1.ToString(), obj2.ToString(), obj3.ToString());
+               public static String Concat (Object obj1, Object obj2, Object obj3)
+               {
+                       string s1, s2, s3;
+                       if (obj1 == null)
+                               s1 = String.Empty;
+                       else
+                               s1 = obj1.ToString ();
+
+                       if (obj2 == null)
+                               s2 = String.Empty;
+                       else
+                               s2 = obj2.ToString ();
+
+                       if (obj3 == null)
+                               s3 = String.Empty;
+                       else
+                               s3 = obj3.ToString ();
+
+                       return Concat (s1, s2, s3);
                }
 
-               //
-               // I can not find the "__arglist" argument on the spec
-               //
-#if !__MonoCS__
+#if ! BOOTSTRAP_WITH_OLDLIB
                [CLSCompliant(false)]
-               public static String Concat (Object arg0, Object arg1, Object arg2, Object arg3, __arglist)
+               public static String Concat (Object obj1, Object obj2, Object obj3,
+                                            Object obj4, __arglist)
                {
-                       throw new NotImplementedException();
+                       string s1, s2, s3, s4;
+
+                       if (obj1 == null)
+                               s1 = String.Empty;
+                       else
+                               s1 = obj1.ToString ();
+
+                       if (obj2 == null)
+                               s2 = String.Empty;
+                       else
+                               s2 = obj2.ToString ();
+
+                       if (obj3 == null)
+                               s3 = String.Empty;
+                       else
+                               s3 = obj3.ToString ();
+
+                       ArgIterator iter = new ArgIterator (__arglist);
+                       int argCount = iter.GetRemainingCount();
+
+                       StringBuilder sb = new StringBuilder ();
+                       if (obj4 != null)
+                               sb.Append (obj4.ToString ());
+
+                       for (int i = 0; i < argCount; i++) {
+                               TypedReference typedRef = iter.GetNextArg ();
+                               sb.Append (TypedReference.ToObject (typedRef));
+                       }
+
+                       s4 = sb.ToString ();
+
+                       return Concat (s1, s2, s3, s4);                 
                }
 #endif
-               public static String Concat(String s1, String s2) {
-                       if (null == s1) {
-                               if (null == s2) { return String.Empty; }
+
+               public unsafe static String Concat (String s1, String s2)
+               {
+                       if (s1 == null) {
+                               if (s2 == null)
+                                       return String.Empty;
                                return s2;
                        }
 
-                       if (null == s2) { return s1; }
+                       if (s2 == null)
+                               return s1; 
+
+                       String tmp = InternalAllocateStr (s1.length + s2.length);
+
+                       if (s1.Length != 0) {
+                               fixed (char *dest = tmp, src = s1) {
+                                       memcpy ((byte*)dest, (byte*)src, s1.length * 2);
+                               }
+                       }
+                       if (s2.Length != 0) {
+                               fixed (char *dest = tmp, src = s2) {
+                                       memcpy ((byte*)(dest + s1.Length), (byte*)src, s2.length * 2);
+                               }
+                       }
 
-                       String tmp = InternalAllocateStr(s1.length + s2.length);
-            
-                       InternalStrcpy(tmp, 0, s1);
-                       InternalStrcpy(tmp, s1.length, s2);
-            
                        return tmp;
                }
 
-               public static String Concat(String s1, String s2, String s3) {
-                       if (null == s1 && null == s2 && null == s3) {
-                               return String.Empty;
+               public unsafe static String Concat (String s1, String s2, String s3)
+               {
+                       if (s1 == null){
+                               if (s2 == null){
+                                       if (s3 == null)
+                                               return String.Empty;
+                                       return s3;
+                               } else {
+                                       if (s3 == null)
+                                               return s2;
+                               }
+                               s1 = String.Empty;
+                       } else {
+                               if (s2 == null){
+                                       if (s3 == null)
+                                               return s1;
+                                       else
+                                               s2 = String.Empty;
+                               } else {
+                                       if (s3 == null)
+                                               s3 = String.Empty;
+                               }
                        }
 
-                       if (null == s1) { s1 = String.Empty; }
-                       if (null == s2) { s2 = String.Empty; }
-                       if (null == s3) { s3 = String.Empty; }
+                       //return InternalConcat (s1, s2, s3);
+                       String tmp = InternalAllocateStr (s1.length + s2.length + s3.length);
 
-                       String tmp = InternalAllocateStr(s1.length + s2.length + s3.length);
-
-                       InternalStrcpy(tmp, 0, s1);
-                       InternalStrcpy(tmp, s1.length, s2);
-                       InternalStrcpy(tmp, s1.length + s2.length, s3);
+                       if (s1.Length != 0) {
+                               fixed (char *dest = tmp, src = s1) {
+                                       memcpy ((byte*)dest, (byte*)src, s1.length * 2);
+                               }
+                       }
+                       if (s2.Length != 0) {
+                               fixed (char *dest = tmp, src = s2) {
+                                       memcpy ((byte*)(dest + s1.Length), (byte*)src, s2.length * 2);
+                               }
+                       }
+                       if (s3.Length != 0) {
+                               fixed (char *dest = tmp, src = s3) {
+                                       memcpy ((byte*)(dest + s1.Length + s2.Length), (byte*)src, s3.length * 2);
+                               }
+                       }
 
                        return tmp;
                }
 
-               public static String Concat(String s1, String s2, String s3, String s4) {
-                       if (null == s1 && null == s2 && null == s3 && null == s4) {
+               public unsafe static String Concat (String s1, String s2, String s3, String s4)
+               {
+                       if (s1 == null && s2 == null && s3 == null && s4 == null)
                                return String.Empty;
-                       }
 
-                       if (null == s1) { s1 = String.Empty; }
-                       if (null == s2) { s2 = String.Empty; }
-                       if (null == s3) { s3 = String.Empty; }
-                       if (null == s4) { s4 = String.Empty; }
+                       if (s1 == null)
+                               s1 = String.Empty;
+                       if (s2 == null)
+                               s2 = String.Empty;
+                       if (s3 == null)
+                               s3 = String.Empty;
+                       if (s4 == null)
+                               s4 = String.Empty;
 
-                       String tmp = InternalAllocateStr(s1.length + s2.length + s3.length + s4.length);
+                       String tmp = InternalAllocateStr (s1.length + s2.length + s3.length + s4.length);
 
-                       InternalStrcpy(tmp, 0, s1);
-                       InternalStrcpy(tmp, s1.length, s2);
-                       InternalStrcpy(tmp, s1.length + s2.length, s3);
-                       InternalStrcpy(tmp, s1.length + s2.length + s3.length, s4);
+                       if (s1.Length != 0) {
+                               fixed (char *dest = tmp, src = s1) {
+                                       memcpy ((byte*)dest, (byte*)src, s1.length * 2);
+                               }
+                       }
+                       if (s2.Length != 0) {
+                               fixed (char *dest = tmp, src = s2) {
+                                       memcpy ((byte*)(dest + s1.Length), (byte*)src, s2.length * 2);
+                               }
+                       }
+                       if (s3.Length != 0) {
+                               fixed (char *dest = tmp, src = s3) {
+                                       memcpy ((byte*)(dest + s1.Length + s2.Length), (byte*)src, s3.length * 2);
+                               }
+                       }
+                       if (s4.Length != 0) {
+                               fixed (char *dest = tmp, src = s4) {
+                                       memcpy ((byte*)(dest + s1.Length + s2.Length + s3.Length), (byte*)src, s4.length * 2);
+                               }
+                       }
 
                        return tmp;
                }
 
-               public static String Concat(params Object[] args) {
-                       string [] strings;
-                       int len, i, currentpos;
+               public static String Concat (params Object[] args)
+               {
+                       if (args == null)
+                               throw new ArgumentNullException ("args");
 
-                       if (null == args)
-                               throw new ArgumentNullException ();
+                       int i = args.Length;
+                       if (i == 0)
+                               return String.Empty;
 
-                       strings = new string [args.Length];
-                       len = 0;
+                       string [] strings = new string [i];
                        i = 0;
+                       int len = 0;
                        foreach (object arg in args) {
-                               /* use Empty for each null argument */
-                               if (arg == null)
+                               if (arg == null) {
                                        strings[i] = String.Empty;
-                               else
+                               } else {
                                        strings[i] = arg.ToString ();
-                               len += strings[i].length;
+                                       len += strings[i].length;
+                               }
                                i++;
                        }
 
                        if (len == 0)
                                return String.Empty;
 
-                       currentpos = 0;
-
-                       String tmp = InternalAllocateStr(len);
-                       for (i = 0; i < strings.Length; i++) {
-                               InternalStrcpy(tmp, currentpos, strings[i]);
-                               currentpos += strings[i].length;
-                       }
-
-                       return tmp;
+                       return InternalJoin (String.Empty, strings, 0, strings.Length);
                }
 
-               public static String Concat(params String[] values) {
-                       int len, i, currentpos;
-
+               public static String Concat (params String[] values)
+               {
                        if (values == null)
-                               throw new ArgumentNullException ();
-
-                       len = 0;
-                       foreach (string value in values)
-                               len += value != null ? value.length : 0;
+                               throw new ArgumentNullException ("values");
 
-                       if (len == 0)
-                               return String.Empty;
+                       return InternalJoin (String.Empty, values, 0, values.Length);
+               }
 
-                       currentpos = 0;
+               public unsafe String Insert (int startIndex, String value)
+               {
+                       if (value == null)
+                               throw new ArgumentNullException ("value");
 
-                       String tmp = InternalAllocateStr(len);
-                       for (i = 0; i < values.Length; i++) {
-                               if (values[i] == null)
-                                       continue;
+                       if (startIndex < 0 || startIndex > this.length)
+                               throw new ArgumentOutOfRangeException ();
 
-                               InternalStrcpy(tmp, currentpos, values[i]);
-                               currentpos += values[i].length;
-                       }       
-       
+                       if (value.Length == 0)
+                               return this;
+                       if (this.Length == 0)
+                               return value;
+                       String tmp = InternalAllocateStr (this.length + value.length);
+
+                       fixed (char *dest = tmp, src = this, val = value) {
+                               char *dst = dest;
+                               memcpy ((byte*)dst, (byte*)src, startIndex * 2);
+                               dst += startIndex;
+                               memcpy ((byte*)dst, (byte*)val, value.length * 2);
+                               dst += value.length;
+                               memcpy ((byte*)dst, (byte*)(src + startIndex), (length - startIndex) * 2);
+                       }
                        return tmp;
                }
 
-               public String Insert(int sindex, String value) {
-                       if (null == value)
-                               throw new ArgumentNullException();
-
-                       if (sindex < 0 || sindex > this.length)
-                               throw new ArgumentOutOfRangeException();
-       
-                       return InternalInsert(sindex, value);
-               }
-
 
-               public static string Intern (string str) {
-                       if (null == str)
-                               throw new ArgumentNullException ();
+               public static string Intern (string str)
+               {
+                       if (str == null)
+                               throw new ArgumentNullException ("str");
 
-                       return InternalIntern(str);
+                       return InternalIntern (str);
                }
 
-               public static string IsInterned (string str) {
-                       if (null == str)
-                               throw new ArgumentNullException();
+               public static string IsInterned (string str)
+               {
+                       if (str == null)
+                               throw new ArgumentNullException ("str");
 
-                       return InternalIsInterned(str);
+                       return InternalIsInterned (str);
                }
        
-               public static string Join (string separator, string [] value) {
+               public static string Join (string separator, string [] value)
+               {
                        if (value == null)
-                               throw new ArgumentNullException ();
+                               throw new ArgumentNullException ("value");
 
-                       return Join(separator, value, 0, value.Length);
+                       return Join (separator, value, 0, value.Length);
                }
 
-               public static string Join(string separator, string[] value, int sindex, int count) {
+               public static string Join (string separator, string[] value, int startIndex, int count)
+               {
                        if (value == null)
-                               throw new ArgumentNullException ();
-
-                       if (sindex + count > value.Length)
-                               throw new ArgumentOutOfRangeException ();
+                               throw new ArgumentNullException ("value");
+                       if (startIndex < 0)
+                               throw new ArgumentOutOfRangeException ("startIndex", "< 0");
+                       if (count < 0)
+                               throw new ArgumentOutOfRangeException ("count", "< 0");
+                       // re-ordered to avoid possible integer overflow
+                       if (startIndex > value.Length - count)
+                               throw new ArgumentOutOfRangeException ("startIndex + count > value.length");
 
-                       if (sindex == value.Length)
+                       if (startIndex == value.Length)
                                return String.Empty;
+                       if (separator == null)
+                               separator = String.Empty;
 
-                       return InternalJoin(separator, value, sindex, count);
+                       return InternalJoin (separator, value, startIndex, count);
                }
 
-               bool IConvertible.ToBoolean (IFormatProvider provider) {
-                       return Convert.ToBoolean (this);
+               bool IConvertible.ToBoolean (IFormatProvider provider)
+               {
+                       return Convert.ToBoolean (this, provider);
                }
-               
-               byte IConvertible.ToByte (IFormatProvider provider) {
-                       return Convert.ToByte (this);
+
+               byte IConvertible.ToByte (IFormatProvider provider)
+               {
+                       return Convert.ToByte (this, provider);
                }
-               
-               char IConvertible.ToChar (IFormatProvider provider) {
-                       return Convert.ToChar (this);
+
+               char IConvertible.ToChar (IFormatProvider provider)
+               {
+                       return Convert.ToChar (this, provider);
                }
 
-               DateTime IConvertible.ToDateTime (IFormatProvider provider) {
-                       return Convert.ToDateTime (this);
+               DateTime IConvertible.ToDateTime (IFormatProvider provider)
+               {
+                       return Convert.ToDateTime (this, provider);
                }
 
-               decimal IConvertible.ToDecimal (IFormatProvider provider) {
-                       return Convert.ToDecimal (this);
+               decimal IConvertible.ToDecimal (IFormatProvider provider)
+               {
+                       return Convert.ToDecimal (this, provider);
                }
 
-               double IConvertible.ToDouble (IFormatProvider provider) {
-                       return Convert.ToDouble (this);
+               double IConvertible.ToDouble (IFormatProvider provider)
+               {
+                       return Convert.ToDouble (this, provider);
                }
 
-               short IConvertible.ToInt16 (IFormatProvider provider) {
-                       return Convert.ToInt16 (this);
+               short IConvertible.ToInt16 (IFormatProvider provider)
+               {
+                       return Convert.ToInt16 (this, provider);
                }
 
-               int IConvertible.ToInt32 (IFormatProvider provider) {
-                       return Convert.ToInt32 (this);
+               int IConvertible.ToInt32 (IFormatProvider provider)
+               {
+                       return Convert.ToInt32 (this, provider);
                }
 
-               long IConvertible.ToInt64 (IFormatProvider provider) {
-                       return Convert.ToInt64 (this);
+               long IConvertible.ToInt64 (IFormatProvider provider)
+               {
+                       return Convert.ToInt64 (this, provider);
                }
        
-               [CLSCompliant(false)]
-               sbyte IConvertible.ToSByte (IFormatProvider provider) {
-                       return Convert.ToSByte (this);
+               sbyte IConvertible.ToSByte (IFormatProvider provider)
+               {
+                       return Convert.ToSByte (this, provider);
                }
 
-               float IConvertible.ToSingle (IFormatProvider provider) {
-                       return Convert.ToSingle (this);
+               float IConvertible.ToSingle (IFormatProvider provider)
+               {
+                       return Convert.ToSingle (this, provider);
                }
-               string IConvertible.ToString (IFormatProvider format) {
+
+               string IConvertible.ToString (IFormatProvider format)
+               {
                        return this;
                }
 
-               object IConvertible.ToType (Type conversionType, IFormatProvider provider) {
+               object IConvertible.ToType (Type conversionType, IFormatProvider provider)
+               {
                        return Convert.ToType (this, conversionType,  provider);
                }
 
-               [CLSCompliant(false)]
-               ushort IConvertible.ToUInt16 (IFormatProvider provider) {
-                       return Convert.ToUInt16 (this);
+               ushort IConvertible.ToUInt16 (IFormatProvider provider)
+               {
+                       return Convert.ToUInt16 (this, provider);
                }
 
-               [CLSCompliant(false)]
-               uint IConvertible.ToUInt32 (IFormatProvider provider) {
-                       return Convert.ToUInt32 (this);
+               uint IConvertible.ToUInt32 (IFormatProvider provider)
+               {
+                       return Convert.ToUInt32 (this, provider);
                }
 
-               [CLSCompliant(false)]
-               ulong IConvertible.ToUInt64 (IFormatProvider provider) {
-                       return Convert.ToUInt64 (this);
+               ulong IConvertible.ToUInt64 (IFormatProvider provider)
+               {
+                       return Convert.ToUInt64 (this, provider);
                }
 
-               TypeCode IConvertible.GetTypeCode () {
+               TypeCode IConvertible.GetTypeCode ()
+               {
                        return TypeCode.String;
                }
 
@@ -922,41 +1518,54 @@ namespace System {
                        }
                }
 
-               public CharEnumerator GetEnumerator () {
+               public CharEnumerator GetEnumerator ()
+               {
                        return new CharEnumerator (this);
                }
-               
-               IEnumerator IEnumerable.GetEnumerator () {
+
+               IEnumerator IEnumerable.GetEnumerator ()
+               {
                        return new CharEnumerator (this);
                }
 
-               private static void ParseFormatSpecifier (string str, ref int ptr, out int n, out int width, out bool left_align, out string format) {
+               private static void ParseFormatSpecifier (string str, ref int ptr, out int n, out int width,
+                                                         out bool left_align, out string format)
+               {
                        // parses format specifier of form:
-                       //   N,[[-]M][:F]}
+                       //   N,[\ +[-]M][:F]}
                        //
                        // where:
 
                        try {
                                // N = argument number (non-negative integer)
-                       
+
                                n = ParseDecimal (str, ref ptr);
                                if (n < 0)
-                                       throw new FormatException ("Input string was not in correct format.");
-                               
+                                       throw new FormatException ("Input string was not in correct format.");
+
                                // M = width (non-negative integer)
 
                                if (str[ptr] == ',') {
-                                       left_align = (str[++ ptr] == '-');
+                                       // White space between ',' and number or sign.
+                                       ++ptr;
+                                       while (Char.IsWhiteSpace (str [ptr]))
+                                               ++ptr;
+                                       int start = ptr;
+
+                                       format = str.Substring (start, ptr - start);
+
+                                       left_align = (str [ptr] == '-');
                                        if (left_align)
                                                ++ ptr;
 
                                        width = ParseDecimal (str, ref ptr);
                                        if (width < 0)
-                                               throw new FormatException ("Input string was not in correct format.");
+                                               throw new FormatException ("Input string was not in correct format.");
                                }
                                else {
                                        width = 0;
                                        left_align = false;
+                                       format = "";
                                }
 
                                // F = argument format (string)
@@ -966,20 +1575,21 @@ namespace System {
                                        while (str[ptr] != '}')
                                                ++ ptr;
 
-                                       format = str.Substring (start, ptr - start);
+                                       format += str.Substring (start, ptr - start);
                                }
                                else
                                        format = null;
 
                                if (str[ptr ++] != '}')
-                                       throw new FormatException ("Input string was not in correct format.");
+                                       throw new FormatException ("Input string was not in correct format.");
                        }
                        catch (IndexOutOfRangeException) {
-                               throw new FormatException ("Input string was not in correct format.");
+                               throw new FormatException ("Input string was not in correct format.");
                        }
                }
 
-               private static int ParseDecimal (string str, ref int ptr) {
+               private static int ParseDecimal (string str, ref int ptr)
+               {
                        int p = ptr;
                        int n = 0;
                        while (true) {
@@ -993,78 +1603,280 @@ namespace System {
 
                        if (p == ptr)
                                return -1;
-                       
+
                        ptr = p;
                        return n;
                }
-               
-               [MethodImplAttribute(MethodImplOptions.InternalCall)]
-               private extern static string InternalJoin(string separator, string[] value, int sindex, int count);
-               
-               [MethodImplAttribute(MethodImplOptions.InternalCall)]
-               private extern String InternalInsert(int sindex, String value);
 
-               [MethodImplAttribute(MethodImplOptions.InternalCall)]
-               private extern String InternalReplace(char oldChar, char newChar);
+               internal unsafe void InternalSetChar (int idx, char val)
+               {
+                       if ((uint) idx >= (uint) Length)
+                               throw new ArgumentOutOfRangeException ("idx");
 
-               [MethodImplAttribute(MethodImplOptions.InternalCall)]
-               private extern String InternalReplace(String oldValue, String newValue);
-    
-               [MethodImplAttribute(MethodImplOptions.InternalCall)]
-               private extern String InternalRemove(int sindex, int count);
-               
-               [MethodImplAttribute(MethodImplOptions.InternalCall)]
-               private extern void InternalCopyTo(int sindex, char[] dest, int dindex, int count);
+                       fixed (char * pStr = &start_char) 
+                       {
+                               pStr [idx] = val;
+                       }
+               }
+
+               internal unsafe void InternalSetLength (int newLength)
+               {
+                       if (newLength > length)
+                               throw new ArgumentOutOfRangeException ("newLength", "newLength as to be <= length");
+
+                       length = newLength;
+
+                       // zero terminate, we can pass string objects directly via pinvoke
+                       fixed (char * pStr = &start_char) {
+                               pStr [length] = '\0';
+                       }
+               }
+
+#if NET_2_0
+               [ReliabilityContractAttribute (Consistency.WillNotCorruptState, Cer.MayFail)]
+#endif
+               public unsafe override int GetHashCode ()
+               {
+                       fixed (char * c = this) {
+                               char * cc = c;
+                               char * end = cc + length - 1;
+                               int h = 0;
+                               for (;cc < end; cc += 2) {
+                                       h = (h << 5) - h + *cc;
+                                       h = (h << 5) - h + cc [1];
+                               }
+                               ++end;
+                               if (cc < end)
+                                       h = (h << 5) - h + *cc;
+                               return h;
+                       }
+               }
+
+               /* helpers used by the runtime as well as above or eslewhere in corlib */
+               internal static unsafe void memset (byte *dest, int val, int len)
+               {
+                       if (len < 8) {
+                               while (len != 0) {
+                                       *dest = (byte)val;
+                                       ++dest;
+                                       --len;
+                               }
+                               return;
+                       }
+                       if (val != 0) {
+                               val = val | (val << 8);
+                               val = val | (val << 16);
+                       }
+                       // align to 4
+                       int rest = (int)dest & 3;
+                       if (rest != 0) {
+                               rest = 4 - rest;
+                               len -= rest;
+                               do {
+                                       *dest = (byte)val;
+                                       ++dest;
+                                       --rest;
+                               } while (rest != 0);
+                       }
+                       while (len >= 16) {
+                               ((int*)dest) [0] = val;
+                               ((int*)dest) [1] = val;
+                               ((int*)dest) [2] = val;
+                               ((int*)dest) [3] = val;
+                               dest += 16;
+                               len -= 16;
+                       }
+                       while (len >= 4) {
+                               ((int*)dest) [0] = val;
+                               dest += 4;
+                               len -= 4;
+                       }
+                       // tail bytes
+                       while (len > 0) {
+                               *dest = (byte)val;
+                               dest++;
+                               len--;
+                       }
+               }
+
+               internal static unsafe void memcpy4 (byte *dest, byte *src, int size) {
+                       /*while (size >= 32) {
+                               // using long is better than int and slower than double
+                               // FIXME: enable this only on correct alignment or on platforms
+                               // that can tolerate unaligned reads/writes of doubles
+                               ((double*)dest) [0] = ((double*)src) [0];
+                               ((double*)dest) [1] = ((double*)src) [1];
+                               ((double*)dest) [2] = ((double*)src) [2];
+                               ((double*)dest) [3] = ((double*)src) [3];
+                               dest += 32;
+                               src += 32;
+                               size -= 32;
+                       }*/
+                       while (size >= 16) {
+                               ((int*)dest) [0] = ((int*)src) [0];
+                               ((int*)dest) [1] = ((int*)src) [1];
+                               ((int*)dest) [2] = ((int*)src) [2];
+                               ((int*)dest) [3] = ((int*)src) [3];
+                               dest += 16;
+                               src += 16;
+                               size -= 16;
+                       }
+                       while (size >= 4) {
+                               ((int*)dest) [0] = ((int*)src) [0];
+                               dest += 4;
+                               src += 4;
+                               size -= 4;
+                       }
+                       while (size > 0) {
+                               ((byte*)dest) [0] = ((byte*)src) [0];
+                               dest += 1;
+                               src += 1;
+                               --size;
+                       }
+               }
+               static unsafe void memcpy2 (byte *dest, byte *src, int size) {
+                       while (size >= 8) {
+                               ((short*)dest) [0] = ((short*)src) [0];
+                               ((short*)dest) [1] = ((short*)src) [1];
+                               ((short*)dest) [2] = ((short*)src) [2];
+                               ((short*)dest) [3] = ((short*)src) [3];
+                               dest += 8;
+                               src += 8;
+                               size -= 8;
+                       }
+                       while (size >= 2) {
+                               ((short*)dest) [0] = ((short*)src) [0];
+                               dest += 2;
+                               src += 2;
+                               size -= 2;
+                       }
+                       if (size > 0)
+                               ((byte*)dest) [0] = ((byte*)src) [0];
+               }
+               static unsafe void memcpy1 (byte *dest, byte *src, int size) {
+                       while (size >= 8) {
+                               ((byte*)dest) [0] = ((byte*)src) [0];
+                               ((byte*)dest) [1] = ((byte*)src) [1];
+                               ((byte*)dest) [2] = ((byte*)src) [2];
+                               ((byte*)dest) [3] = ((byte*)src) [3];
+                               ((byte*)dest) [4] = ((byte*)src) [4];
+                               ((byte*)dest) [5] = ((byte*)src) [5];
+                               ((byte*)dest) [6] = ((byte*)src) [6];
+                               ((byte*)dest) [7] = ((byte*)src) [7];
+                               dest += 8;
+                               src += 8;
+                               size -= 8;
+                       }
+                       while (size >= 2) {
+                               ((byte*)dest) [0] = ((byte*)src) [0];
+                               ((byte*)dest) [1] = ((byte*)src) [1];
+                               dest += 2;
+                               src += 2;
+                               size -= 2;
+                       }
+                       if (size > 0)
+                               ((byte*)dest) [0] = ((byte*)src) [0];
+               }
+               static unsafe void memcpy (byte *dest, byte *src, int size) {
+                       // FIXME: if pointers are not aligned, try to align them
+                       // so a faster routine can be used. Handle the case where
+                       // the pointers can't be reduced to have the same alignment
+                       // (just ignore the issue on x86?)
+                       if ((((int)dest | (int)src) & 3) != 0) {
+                               if (((int)dest & 1) != 0 && ((int)src & 1) != 0 && size >= 1) {
+                                       dest [0] = src [0];
+                                       ++dest;
+                                       ++src;
+                                       --size;
+                               }
+                               if (((int)dest & 2) != 0 && ((int)src & 2) != 0 && size >= 2) {
+                                       ((short*)dest) [0] = ((short*)src) [0];
+                                       dest += 2;
+                                       src += 2;
+                                       size -= 2;
+                               }
+                               if ((((int)dest | (int)src) & 1) != 0) {
+                                       memcpy1 (dest, src, size);
+                                       return;
+                               }
+                               if ((((int)dest | (int)src) & 2) != 0) {
+                                       memcpy2 (dest, src, size);
+                                       return;
+                               }
+                       }
+                       memcpy4 (dest, src, size);
+               }
+
+               [CLSCompliant (false), MethodImplAttribute (MethodImplOptions.InternalCall)]
+               unsafe public extern String (char *value);
+
+               [CLSCompliant (false), MethodImplAttribute (MethodImplOptions.InternalCall)]
+               unsafe public extern String (char *value, int startIndex, int length);
+
+               [CLSCompliant (false), MethodImplAttribute (MethodImplOptions.InternalCall)]
+               unsafe public extern String (sbyte *value);
+
+               [CLSCompliant (false), MethodImplAttribute (MethodImplOptions.InternalCall)]
+               unsafe public extern String (sbyte *value, int startIndex, int length);
+
+               [CLSCompliant (false), MethodImplAttribute (MethodImplOptions.InternalCall)]
+               unsafe public extern String (sbyte *value, int startIndex, int length, Encoding enc);
+
+               [MethodImplAttribute (MethodImplOptions.InternalCall)]
+               public extern String (char [] val, int startIndex, int length);
+
+               [MethodImplAttribute (MethodImplOptions.InternalCall)]
+               public extern String (char [] val);
 
-               [MethodImplAttribute(MethodImplOptions.InternalCall)]
-               private extern String[] InternalSplit(char[] separator, int count);
+               [MethodImplAttribute (MethodImplOptions.InternalCall)]
+               public extern String (char c, int count);
 
-               [MethodImplAttribute(MethodImplOptions.InternalCall)]
-               private extern String InternalTrim(char[] chars, int typ);
+               [MethodImplAttribute (MethodImplOptions.InternalCall)]
+               private extern static string InternalJoin (string separator, string[] value, int sIndex, int count);
 
-               [MethodImplAttribute(MethodImplOptions.InternalCall)]
-               private extern int InternalIndexOf(char value, int sindex, int count);
+               [MethodImplAttribute (MethodImplOptions.InternalCall)]
+               private extern String InternalReplace (char oldChar, char newChar);
 
-               [MethodImplAttribute(MethodImplOptions.InternalCall)]
-               private extern int InternalIndexOf(string value, int sindex, int count);
+               [MethodImplAttribute (MethodImplOptions.InternalCall)]
+               private extern String InternalReplace (String oldValue, string newValue, CompareInfo comp);
 
-               [MethodImplAttribute(MethodImplOptions.InternalCall)]
-               private extern int InternalIndexOfAny(char [] arr, int sindex, int count);
+               [MethodImplAttribute (MethodImplOptions.InternalCall)]
+               private extern void InternalCopyTo (int sIndex, char[] dest, int destIndex, int count);
 
-               [MethodImplAttribute(MethodImplOptions.InternalCall)]
-               private extern int InternalLastIndexOf(char value, int sindex, int count);
+               [MethodImplAttribute (MethodImplOptions.InternalCall)]
+               private extern String[] InternalSplit (char[] separator, int count);
 
-               [MethodImplAttribute(MethodImplOptions.InternalCall)]
-               private extern int InternalLastIndexOf(String value, int sindex, int count);
+               [MethodImplAttribute (MethodImplOptions.InternalCall)]
+               private extern String InternalTrim (char[] chars, int typ);
 
-               [MethodImplAttribute(MethodImplOptions.InternalCall)]
-               private extern int InternalLastIndexOfAny(char [] anyOf, int sindex, int count);
+               [MethodImplAttribute (MethodImplOptions.InternalCall)]
+               private extern int InternalIndexOfAny (char [] arr, int sIndex, int count);
 
-               [MethodImplAttribute(MethodImplOptions.InternalCall)]
-               private extern String InternalPad(int width, char chr, bool right);
+               [MethodImplAttribute (MethodImplOptions.InternalCall)]
+               private extern int InternalLastIndexOfAny (char [] anyOf, int sIndex, int count);
 
-               [MethodImplAttribute(MethodImplOptions.InternalCall)]
-               private extern String InternalToLower();
+               [MethodImplAttribute (MethodImplOptions.InternalCall)]
+               private extern String InternalPad (int width, char chr, bool right);
 
-               [MethodImplAttribute(MethodImplOptions.InternalCall)]
-               private extern String InternalToUpper();
+               [MethodImplAttribute (MethodImplOptions.InternalCall)]
+               internal extern static String InternalAllocateStr (int length);
 
-               [MethodImplAttribute(MethodImplOptions.InternalCall)]
-               private extern static String InternalAllocateStr(int length);
+               [MethodImplAttribute (MethodImplOptions.InternalCall)]
+               internal extern static void InternalStrcpy (String dest, int destPos, String src);
 
-               [MethodImplAttribute(MethodImplOptions.InternalCall)]
-               private extern static void InternalStrcpy(String dest, int destPos, String src);
+               [MethodImplAttribute (MethodImplOptions.InternalCall)]
+               internal extern static void InternalStrcpy (String dest, int destPos, char[] chars);
 
-               [MethodImplAttribute(MethodImplOptions.InternalCall)]
-               private extern static void InternalStrcpy(String dest, int destPos, String src, int startPos, int count);
+               [MethodImplAttribute (MethodImplOptions.InternalCall)]
+               internal extern static void InternalStrcpy (String dest, int destPos, String src, int sPos, int count);
 
-               [MethodImplAttribute(MethodImplOptions.InternalCall)]
-               private extern static string InternalIntern(string str);
+               [MethodImplAttribute (MethodImplOptions.InternalCall)]
+               internal extern static void InternalStrcpy (String dest, int destPos, char[] chars, int sPos, int count);
 
-               [MethodImplAttribute(MethodImplOptions.InternalCall)]
-               private extern static string InternalIsInterned(string str);
+               [MethodImplAttribute (MethodImplOptions.InternalCall)]
+               private extern static string InternalIntern (string str);
 
-               [MethodImplAttribute(MethodImplOptions.InternalCall)]
-               private extern static int InternalCompare(String s1, int i1, String s2, int i2, int length, bool inCase);
+               [MethodImplAttribute (MethodImplOptions.InternalCall)]
+               private extern static string InternalIsInterned (string str);
        }
 }