Bye bye, fast compilation times

[bauss]

On Tuesday, 6 February 2018 at 20:30:42 UTC, Steven Schveighoffer 
wrote:
>
> The regex in question I think is to ensure an email address 
> like abc at 192.168.0.5 has a valid IP address. The D1 function 
> doesn't support that requirement.

>
> -Steve

An invalid IP is not necessarily an invalid email though.

You'd be surprised how much __garbage__ a valid email actually 
can contain.

https://www.w3.org/Protocols/rfc822/

Generally the best way to validate an email is just to check if 
there is a value before @ and a value after.

The real way to validate an email is to check if the email exists 
on a SMTP server, BUT some SMTP servers will not provide such 
information (Such as gmail I think?) and thus you can't really 
rely on that either.