Automatic imports?

[Walter Bright via Digitalmars-d]

On 2/3/2017 4:01 PM, Ali Çehreli wrote:
> void foo(std.datetime.Duration dur) {
>     // ...
> }
>
> Can the compiler automatically import std.datetime for both the implementation
> above and the user? Or, too much beer at work on this Friday? :o)

How does the compiler know that "std" is supposed to be an import rather than a 
misspelling of a previously declared "stc" ?