blocks with attributes vs inlined lambda

[deadalnix]

On Saturday, 8 June 2013 at 14:52:23 UTC, monarch_dodra wrote:
> I remember think that being able to mark specific parts of code 
> with certain attributes, inside a block, could be very useful.
>
> for example:
>
> --------
> void foo()
> {
>    //Code
>
>    /Critical section
>    nothrow {
>        //code here can't throw
>    }
>
>    //More code
> }
> --------
>
> I have since learned that you can do this with lambda's 
> instead, declaring and calling them in a single line:
>
> --------
> void foo()
> {
>    //Code
>
>    /Critical section
>    () nothrow
> {
>        //code here can't throw
>    }
>
>    //More code
> }
> --------

Sound like a nice idiom. Why is the first set of () needed ? Can 
we change the grammar to remove them ?