Specifying C++ symbols in C++ namespaces

[Walter Bright]

On 4/2/2014 7:14 PM, Michel Fortin wrote:
> On 2014-04-03 01:09:43 +0000, Walter Bright <newshound2 at digitalmars.com> said:
>> I considered that, but it fails because:
>>
>> C++:
>>
>>      namespace S { namespace T {
>>          int foo();
>>          namespace U {
>>              int foo();
>>          }
>>       } }
>>
>> D:
>>
>>    extern (C++, S.T) {
>>        int foo();
>>        extern (C++, U) {
>>          int foo();
>>        }
>>    }
>>    foo();  // error, ambiguous, which one?
>>    S.T.foo(); // S undefined
>
> That's a contrived example.

Not at all. The whole point of using namespaces in C++ is to introduce a scope. 
And the whole point of scopes is to have the same name in different scopes 
represent different objects.

> Perhaps I'm wrong, but I'd assume the general use
> case is that all functions in a module will come from the same C++ namespace.

I believe that is an incorrect assumption. C++ namespaces were specifically (and 
wrongly, in my not so humble opinion, but there it is) not designed to be 
closed, nor have any particular relationship with modules.

> For the contrived example above, I think it's fair you have to use a contrived
> solution:

I don't believe that punishing C++ users who dare to try D is the path to 
success for D :-)

> Alternatively you can use another module for the other namespace.

Forcing C++ code that exists in a single file to be split up among multiple D 
files is inflicting unnecessary punishment on the poor guy trying to justify 
migrating to D.