Workaround for DIP 1005

[Daniel N via Digitalmars-d]

On Thursday, 9 February 2017 at 05:40:01 UTC, Jonathan M Davis 
wrote:
> The import is only listed once, whereas with this technique, 
> you have to list it for each symbol. e.g.
>
> auto foo(from!"std.datetime".SysTime st1,
>          from!"std.datetime".SysTime st2,
>          from!"std.datetime".Duration d);
>
> The result is much more verbose, and if you have several 
> symbols that need imports between the return type, parameters, 
> and template constraint, you quickly end up with a lot of extra 
> text in the middle of your function signatures just because you 
> want to tie the imports to the functions that use them.
> - Jonathan M Davis

Thank you for your insightful feedback, I'm currently pressed for 
time but I can at least begin to address one of your concerns.

Every proposed solution has some sort of tradeoff, verbosity 
could be dealt with for the price of turning a simple function 
into a template. In some cases this could be acceptable in others 
prohibitive.

auto
foo(alias dt = from!"std.datetime")
    (dt.SysTime  st1,
     dt.SysTime  st2,
     dt.Duration d)

Our "Implicit Function-Template Instantiation" also unfortunately 
bails with default arguments... maybe there is an enhancement 
request for that already?

@(from!"std.datetime") almost works too(it would avoid turning 
the function into a template), but has other issues.