Passing pointer to extern(C++) templated function

Ali Çehreli acehreli at
Tue Oct 13 23:39:38 UTC 2020

On 10/13/20 4:11 PM, James Blachly wrote:
> On 10/13/20 5:23 AM, Jamie wrote:
>> Building with:
>> g++ -c a.cpp
>> dmd main.d a.o
>> Throws the error:
>> /usr/bin/ld: main.o: in function `_Dmain':
>> main.d:(.text._Dmain[_Dmain]+0x31): undefined reference to `void 
>> func3<int>(int*, int*)'
>> /usr/bin/ld: main.d:(.text._Dmain[_Dmain]+0x3e): undefined reference 
>> to `void func4<int>(int const*, int const)'
>> collect2: error: ld returned 1 exit status
>> Error: linker exited with status 1
> Is the template even instantiated? With just a template definition and 
> an object file I am surprised you even have a symbol?

Yes, they all have explicit template instantiations on the C++ side.

I think the issue is with D's "turtles all the way down" style const. My 
workaround would be to define wrapper functions that may need to do 
casting on one or the other side.


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