[swift-dev] Where are @_attributes documented?

[Joe Groff]

> On Dec 30, 2015, at 4:58 PM, Ling Wang via swift-dev <swift-dev at swift.org> wrote:
> 
> I want to submit some patches but I’m not sure whether I should apply some @_attributes(like @_transparent and @_semantics) that I see in stdlib to my API because I don’t know their meanings.

If it starts with an underscore, the answer is always "no, unless you're the standard library". These attributes are compiler-internal and not intended to be used by user code. We reserve the right to change them with reckless abandon.

> Where are they documented?

Some are documented in the compiler's 'doc/' subdirectory in various places.

-Joe