Case Range Statement ..

[Nick Sabalausky]

"Walter Bright" <newshound1 at digitalmars.com> wrote in message 
news:h3088a$2kla$3 at digitalmars.com...
> Nick Sabalausky wrote:
>>  Someone else said it's also an expression
>> that evaluates to 3, but that seems beyond useless to me.
>
> It's handy when you want to prefix one expression to another, as in:
>
>    (foo(), x + 3)
>

I guess I'm not familiar with that syntax. What does that do and for what 
purpose?