Why the @ in @safe? & UDAs

[Jesse Phillips]

On Thursday, 7 November 2013 at 02:04:37 UTC, Adam D. Ruppe wrote:
> On Thursday, 7 November 2013 at 00:13:49 UTC, Shammah 
> Chancellor wrote:
>> My understanding is that @ attributes were for used-defined 
>> behavior only.
>
> It is all a historical thing... at first, all new things were 
> done as keywords. Then around the time @safe came around, they 
> were changing their minds and new things became @keywords. 
> Then, some time after that, UDAs came around and used the @ 
> syntax.

More specifically, the discussion was around properties and how 
to handle them. User-Defined attributes were also being thrown 
around, and at some point a suggestion combined the two 
suggesting properties be denoted with @property. Some time passed 
and suddenly D could parse @property on functions (@safe may have 
been added at the same time, or a little later). No UDA[1] was 
introduced.

1. http://prowiki.org/wiki4d/wiki.cgi?LanguageDevel/DIPs/DIP6