Named constructors

[Steven Schveighoffer]

On 1/10/19 1:49 PM, H. S. Teoh wrote:

> The last time somebody looked, the real problem wasn't that Phobos (or
> any 3rd party library) unittests were being compiled over and over; it
> was caused by a change in template instantiation behaviour when
> -unittest is specified, such that many more templates are instantiated
> that probably don't need to be, thus causing the observed compile-time
> spike.  There's a reason it was done this way, but I'm here gnashing my
> teeth wishing that there was a way to turn off this annoying behaviour.

Yes, it's that when unittest is enabled effectively -allinst is enabled 
as well.

That wasn't the only problem, but it was the main reason why importing 
e.g. std.regex with -unittest was a huge penalty.

-Steve