According to MSDN (Section 11.3.6 of the [C# spec](http://download.microsoft.com/download/3/8/8/388e7205-bc10-4226-b2a8-75351c669b09/CSharp%20Language%20Specification.doc)):

> 
> Within an instance constructor of a
>  struct, `this` corresponds to an `out`
>  parameter of the struct type, and
>  within an instance function member of
>  a struct, `this` corresponds to a `ref`
>  parameter of the struct type. In both
>  cases, `this` is classified as a
>  variable, and it is possible to modify
>  the entire struct for which the
>  function member was invoked by
>  assigning to `this` or by passing `this`
>  as a `ref` or `out` parameter.
> 
> 
> 

I don't get it. How is `this` different for a struct than for a class? Code examples are appreciated