Question

Is there anything like a “Call constraint” for C# ?

For instance i have the following function:

public UInt16 ConvertByteToUInt16 (byte[] buffer)
{
   if (buffer.Length != 2)
   {
       throw new InvalidArgumentException(); 
   }

   Convert();
}

Is it possible to write something like:

public UInt16 ConvertByteToUInt16 (byte[] buffer) : where (buffer.Lenght = 2)
{
    Convert();       
}

And if i call the function like that:

ConvertByteToUInt16 (new byte[] { 0xFF, 0xFF, 0xFF } )

I would like to get an error at compile time.
I am quite sure nothing like that exists on C# 2.0, but maybe on C# 4.0 ?
Thanks in advance.

Answer 1

You can’t do this in standard .NET. You need to manually check, then throw an appropriate exception:

public UInt16 ConvertByteToUInt16 (byte[] buffer)
{
    if (buffer.Length != 2)
        throw new ArgumentException("buffer needs to be of length 2", "buffer");
    Convert();       
}