New in C#4

[Robert Fraser]

Denis Koroskin wrote:
> I once had the following Color class:
> 
> class Color
> {
>     this (byte alpha, byte red, byte green, byte blue) { ... }
> }
> 
> and used it as follows:
> 
> Color c = new Color(255, 0, 255, 0); // opaque green color
> 
> After refactoring, alpha became last argument in ctor:
> 
>     this(byte red, byte green, byte blue, byte alpha) { ... }
> 
> Note that this change didn't raise any compilation error, nothing that 
> would notify my of possible error.
> 
> Needless to say that I didn't enjoy searching all the code that used 
> Color to reorder parameters (although some artifact were nice :)
> It would save me quite some time if I initialized all my instances as 
> follows:
> 
> Color c = new Color(alpha: 255, red: 0, green: 255, blue: 0);
> 
> Now compiler could raise an error if parameters order was changed. Even 
> better - compiler could reorder parameters for me automatically if given 
> that all of them are specified and no params ommited (unlike Python). 
> This makes code more robust to refactoring.

The first thing  I thought of when reading this is Eclipse JDT's "Change 
Method Signature" refactoring that will look up all the calls in your 
project & automatically reorder the parameters for you.