Code fails with linker error. Why?

[eles via Digitalmars-d-learn]

On Monday, 6 October 2014 at 13:23:55 UTC, John Colvin wrote:
> On Monday, 6 October 2014 at 12:16:14 UTC, eles wrote:
>> On Monday, 6 October 2014 at 11:54:56 UTC, John Colvin wrote:
>>> On Monday, 6 October 2014 at 10:10:04 UTC, eles wrote:
>>>> On Saturday, 4 October 2014 at 15:29:57 UTC, John Colvin 
>>>> wrote:
>>>>> On Saturday, 4 October 2014 at 11:19:52 UTC, ketmar via 
>>>>> Digitalmars-d-learn wrote:
>>>>>> On Sat, 04 Oct 2014 11:01:28 +0000
>>>>>> John Colvin via Digitalmars-d-learn

> This isn't a problem. You're not going to get the name-mangling 
> right by accident. Even for free functions the module name is 
> mangled in.

It is. I could erase the definition of an identical class in 
another .d file and accidentally leave an orphan definition 
method therein.

> The only way this can happen is with extern(C) functions, which 
> is because C doesn't mangle it's function names.

This too is a hole. Why to leave holes?

I like the "fromage à trous":

http://fr.wikipedia.org/wiki/Paradoxe_du_fromage_à_trous

But not in my software.