Is there any good reason why C++ namespaces are "closed" in D?

[Walter Bright]

On 7/30/2018 7:20 AM, Atila Neves wrote:
>> ------
>> extern (C++, ns) { int foo() { return 1; } }
>>
>> mixin template X()
>> {
>>   extern (C++, ns) { int bar() { return 2; } }
>> }
>>
>> mixin X!() x;
>>
>> -------
> 
> void main() {
>      pragma(msg, __traits(allMembers, ns));
>      foo;
>      bar;
> }
> 
> $ dmd foo.d
> tuple("foo")
> foo.d(15): Error: undefined identifier bar
> 
> That method doesn't compile.

You'll need to add:

     alias bar = x.bar;

which will add bar to the current scope.


> foo.o:foo.d:function _Dmain: error: undefined reference to 'S::ns::bar()'

Hmm, when I tested it the 'S::' prefix wasn't there. But when I retested it, it 
was. (!) I'll look into this.