public static unsafe string ReplaceEx(this string str, string oldStr, string newStr)
{
if (oldStr.Length != newStr.Length)
{
throw new ArgumentOutOfRangeException("oldStr.Length != newStr.Length");
}
if (oldStr == null)
{
throw new ArgumentNullException("oldStr");
}
if (oldStr.Length == 0)
{
throw new ArgumentException("oldStr is the empty string.");
}
if (str.Length == 0 || oldStr == newStr || oldStr.Length > str.Length)
{
return(str);
}
if (oldStr.Length == 1 && newStr.Length == 1)
{
return(ReplaceEx(str, oldStr[0], newStr[0]));
}
int length = str.Length;
int step = oldStr.Length;
fixed(char *dst = str, s = newStr)
{
for (int i = 0; i < length;)
{
int found = str.IndexOf(oldStr, i, length - i);
if (found < 0)
{
break;
}
CString.CharCopy(dst + i, s, newStr.Length);
i = found + step;
}
}
return(str);
}
public static unsafe void CopyToEx(this string str, int startIndex, string outStr)
{
if (startIndex < 0)
{
throw new ArgumentOutOfRangeException("startIndex", "Cannot be negative.");
}
if (startIndex + outStr.Length > str.Length)
{
throw new ArgumentOutOfRangeException("startIndex", "Cannot exceed length of string.");
}
fixed(char *src = str, dest = outStr)
{
CString.CharCopy(dest, src + startIndex, outStr.Length);
}
}
public static unsafe string ReplaceEx(this string dest, int offset, string src)
{
if (offset < 0)
{
throw new ArgumentOutOfRangeException("offset", "Cannot be negative.");
}
if (offset >= dest.Length)
{
throw new ArgumentOutOfRangeException("offset >= dest.Length");
}
if (offset + src.Length > dest.Length)
{
throw new ArgumentOutOfRangeException("offset + src.Length > dest.Length");
}
fixed(char *dst = dest, s = src)
{
CString.CharCopy(dst + offset, s, src.Length);
}
return(dest);
}