Phobos: __FILE__ as template default parameter

[Johan Engelen via Digitalmars-d]

On Tuesday, 21 June 2016 at 10:39:52 UTC, David Nadlinger wrote:
> On Monday, 20 June 2016 at 08:10:19 UTC, Dicebot wrote:
>> How about defining semantics like "try inlining if possible, 
>> fallback to always emitting symbol to object file otherwise"? 
>> That would also allow compatible implementation in dmd.
>
> This would get rid of the undefined symbols, but there is a 
> much more subtle problem here that nobody has brought up yet: 
> If the template ends up being emitted twice with different 
> mangled names, then, well, it ends up existing twice in the 
> final executable.
>
> This is not really an issue for functions, but very much so for 
> data symbols (e.g. a static variable inside a function), where 
> you could end up with the same alias referring to two different 
> pieces of data depending on where it is used from.
>
> The root of this issue is that __FILE__ introduces incidental 
> environmental state into the otherwise pure module system.

+1