Hi

[template.cpp]:
template<typename Type>
void some_templated_function();

template<>
void some_templated_function<int>()
{}

[main.d]:
extern(C++) {
  void some_templated_function(Type)();
}

void main() {
  some_templated_function!int;
}

compilation:
g++ -c template_with_ns.cpp
dmd main.d template.o

this WORKS! :) BUT, now I put all c++ stuff into a namespace
[template_with_ns.cpp]:
namespace some_namespace {

template<typename Type>
void some_templated_function();

template<>
void some_templated_function<int>()
{}

}

[main_with_ns.d]:
extern(C++, some_namespace) {
  void some_templated_function(Type)();
}

void main() {
  some_templated_function!int;
}

DOES NOT compile
undefined reference to `void some_templated_function<int>()'

nm main_with_ns.o
_Z23some_templated_functionIiEvv
nm template_with_ns.o
_ZN14some_namespace23some_templated_functionIiEEvv

It seems like dmd doesn't care about the namespace of the template.
Can someone confirm this as a bug? or am I doing something terrible wrong? :)

When I retry this with gdc it doesn't compile. Neither with namespace nor without:
nm template.o:
_Z23some_templated_functionIiEvv
main.o:
_ZN23some_templated_functionIiE23some_templated_functionEv

The more I work with D, interfacing C++, the more I start to know "mangling" :D

Have fun
Markus

On 3/16/2018 11:57 AM, Markus wrote:
> It seems like dmd doesn't care about the namespace of the template.
> Can someone confirm this as a bug? or am I doing something terrible wrong? :)

Might check that this https://issues.dlang.org/show_bug.cgi?id=17772 is not the issue. See my comment in https://github.com/dlang/dmd/pull/7906 :

"Fixing the T_ mangling is much more problematic, I don't know how to do that yet. This namespace issue is independent, so it is convenient to do it separately."

On 3/16/18 3:32 PM, Walter Bright wrote:
> On 3/16/2018 11:57 AM, Markus wrote:
>> It seems like dmd doesn't care about the namespace of the template.
>> Can someone confirm this as a bug? or am I doing something terrible wrong? :)
> 
> Might check that this https://issues.dlang.org/show_bug.cgi?id=17772 is not the issue. See my comment in https://github.com/dlang/dmd/pull/7906 :
> 
> "Fixing the T_ mangling is much more problematic, I don't know how to do that yet. This namespace issue is independent, so it is convenient to do it separately."

There was another namespace issue recently found:

https://issues.dlang.org/show_bug.cgi?id=18582

But it looks like its different. When you compare:

C++:
_ZN14some_namespace23some_templated_functionIiEEvv

D:
_ZN23some_templated_functionIiE23some_templated_functionEv

Something is wrong. Instead of the namespace, you get "some_templated_function" as the namespace!

-Steve

On Fri, Mar 16, 2018 at 03:53:00PM -0400, Steven Schveighoffer via Digitalmars-d wrote: [...]
> There was another namespace issue recently found:
> 
> https://issues.dlang.org/show_bug.cgi?id=18582
> 
> But it looks like its different. When you compare:
> 
> C++:
> _ZN14some_namespace23some_templated_functionIiEEvv
> 
> D: _ZN23some_templated_functionIiE23some_templated_functionEv
> 
> Something is wrong. Instead of the namespace, you get "some_templated_function" as the namespace!
[...]

I wonder if the problem is caused by wrongly treating the template function as a D eponymous template instead of a C++ template?


T

-- 
Don't drink and derive. Alcohol and algebra don't mix.