Workflow: how do I make a cpp lib in nim?

[ggibson]

Hi, I've been looking for a couple days and can't find out exactly how this is 
done. Goal: have cpp/h files generated that I can compile in with my c++ 
project to include helper functions originally written in nim. I'll try 
updating to development later to see if that fixes it.

What I'm doing: 
    
    
    $ nim cpp -c -d:release --header --noMain mylib.nim (see below for src)
    $ cd nimcache
    $ ls
    main.cpp (see below for src)
    mylib.cpp
    mylib.h
    <redacted usual nim cpp files>
    $ g++ -o main *.cpp -I/Nim-0.18.0/lib -w
    stdlib_dynlib.cpp: In function 'void* 
symAddr_NHfjIU1Uh0ju9azgMjiSkQA(void*, NCSTRING)':
    stdlib_dynlib.cpp:45:25: error: invalid conversion from 'FARPROC' {aka 
'long long int (*)()'} to 'void*' [-fpermissive]
      result = GetProcAddress(LOC1.dest, name);
    $ gcc --version
    <...> 8.2.0
    
    
    Run
    
    
    // main.cpp
    #include <iostream>
    #include "mylib.h"
    using namespace std; // for demo
    
    extern char** parseCSVListLine(const char*); // Seem to need this because 
mylib.h does not have it (?!)
    
    int main() {
      parseCSVListLine("one,two,three");
      return(0);
    }
    
    
    Run
    
    
    import strutils, sequtils, os, parsecsv, streams, future
    
    proc parseCSVListLine*(str: string):seq[string] =
      var ss = newStringStream(str)
      var p: CsvParser
      p.open(ss, "parseCSVListLine()")
      discard p.readRow()
      return lc[ col.strip() | (col <- items(p.row)), string]
    
    proc parseCSVListLine*(str: cstring):cstringArray {.extern: 
"parseCSVListLine".} =
      return alloccstringArray(parseCSVListLine($str))
    
    
    Run