Requires() public static method

public static Requires ( bool condition ) : void
condition bool
return void
Esempio n. 1
0
 public override TResult Switch <TResult>(Func <TLeft, TResult> left, Func <TRight, TResult> right)
 {
     Contract.Requires(left != null);
     Contract.Requires(right != null);
     return(default(TResult));
 }
        public static String Normalize(this string value, NormalizationForm normalizationForm)
        {
            Contract.Requires(value != null);

            if (value == null)
            {
                throw new ArgumentNullException("value");
            }

            // we depend on Win32 last error when calling NormalizeString
            Interop.mincore.SetLastError(Interop.ERROR_SUCCESS);

            // Guess our buffer size first
            int iLength = Interop.mincore.NormalizeString((int)normalizationForm, value, value.Length, null, 0);

            int lastError = Marshal.GetLastWin32Error();

            // Could have an error (actually it'd be quite hard to have an error here)
            if ((lastError != Interop.ERROR_SUCCESS && lastError != Interop.LAST_ERROR_TRASH_VALUE) ||
                iLength < 0)
            {
                if (lastError == Interop.ERROR_INVALID_PARAMETER)
                {
                    throw new ArgumentException(SR.Argument_InvalidCharSequenceNoIndex, "value");
                }

                // We shouldn't really be able to get here..., guessing length is
                // a trivial math function...
                // Can't really be Out of Memory, but just in case:
                if (lastError == Interop.ERROR_NOT_ENOUGH_MEMORY)
                {
                    throw new OutOfMemoryException(SR.Arg_OutOfMemoryException);
                }

                // Who knows what happened?  Not us!
                throw new InvalidOperationException(SR.Format(SR.UnknownError_Num, lastError));
            }

            // Don't break for empty strings (only possible for D & KD and not really possible at that)
            if (iLength == 0)
            {
                return(String.Empty);
            }

            // Someplace to stick our buffer
            char[] cBuffer = null;

            for (; ;)
            {
                // (re)allocation buffer and normalize string
                cBuffer = new char[iLength];

                // Reset last error
                Interop.mincore.SetLastError(Interop.ERROR_SUCCESS);
                iLength   = Interop.mincore.NormalizeString((int)normalizationForm, value, value.Length, cBuffer, cBuffer.Length);
                lastError = Marshal.GetLastWin32Error();

                if (lastError == Interop.ERROR_SUCCESS || lastError == Interop.LAST_ERROR_TRASH_VALUE)
                {
                    break;
                }

                // Could have an error (actually it'd be quite hard to have an error here)
                switch (lastError)
                {
                // Do appropriate stuff for the individual errors:
                case Interop.ERROR_INSUFFICIENT_BUFFER:
                    iLength = Math.Abs(iLength);
                    Contract.Assert(iLength > cBuffer.Length, "Buffer overflow should have iLength > cBuffer.Length");
                    continue;

                case Interop.ERROR_INVALID_PARAMETER:
                case Interop.ERROR_NO_UNICODE_TRANSLATION:
                    // Illegal code point or order found.  Ie: FFFE or D800 D800, etc.
                    throw new ArgumentException(SR.Argument_InvalidCharSequenceNoIndex, "value");

                case Interop.ERROR_NOT_ENOUGH_MEMORY:
                    throw new OutOfMemoryException(SR.Arg_OutOfMemoryException);

                default:
                    // We shouldn't get here...
                    throw new InvalidOperationException(SR.Format(SR.UnknownError_Num, lastError));
                }
            }

            // Copy our buffer into our new string, which will be the appropriate size
            return(new String(cBuffer, 0, iLength));
        }
Esempio n. 3
0
 public override void Switch(Action <TLeft> left, Action <TRight> right)
 {
     Contract.Requires(left != null);
     Contract.Requires(right != null);
 }