Question: how to use with multiple files and not get linker errors

[crucialfelix]

I'm trying to write classes that have VarSignal members. My problem is with the REACTIVE_DOMAIN macro.

When I include these classes I get linker errors because there is now a duplicate symbol _D_initializer_ in each .o file.

The examples all show one page of code in a single .cpp file (and no header files)

//  DataSource.hpp
#ifndef DataSource_hpp
#define DataSource_hpp

#include "react/Domain.h"
#include "react/Signal.h"
#include "react/Event.h"

REACTIVE_DOMAIN(D, react::sequential)

class DataSource {
 public:
    react::VarSignal<D, int> numDimensions = react::MakeVar<D>(0);
    react::EventSource<D>  didLoad         = react::MakeEventSource<D>();
};

#endif /* DataSource_hpp */

// ofApp.cpp
#pragma once

#import "DataSource.hpp"

class ofApp {
 public:
  // ...

 private:
  DataSource dataSource;
};

The linker now fails because D has been defined twice.

duplicate symbol _D_initializer_ in:
    /Users/crucial/Library/Developer/Xcode/DerivedData/PlaySPLOM-gwpsbmgveykcqsheakzuilcqldtb/Build/Intermediates/PlaySPLOM.build/Debug/PlaySPLOM.build/Objects-normal/x86_64/DataSource.o
    /Users/crucial/Library/Developer/Xcode/DerivedData/PlaySPLOM-gwpsbmgveykcqsheakzuilcqldtb/Build/Intermediates/PlaySPLOM.build/Debug/PlaySPLOM.build/Objects-normal/x86_64/ofApp.o
ld: 2 duplicate symbols for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

Furthermore, should all classes in this application use the same D ? Or should each create their own ? (with a unique name?)
Where ideally should the domain be declared ? I tried

I realize the library is experimental, but I quite like the syntax and was hoping to get this to work for an openFrameworks data visualization/sonification project.

thanks