From: ptkwt@...1.aracnet.com (Phil Tomson)
Date: 2002-06-11T16:19:28+09:00
Subject: SWIG, C++ and static member variables

OK, my terminology may not be correct in C++ terms (I've been doing a lot 
of Ruby and not a lot of C++ until the last few weeks), but, say I've got 
a C++ class with a class variable (statically scoped), like:

//Person.h
class Person {
	static unsigned numPeople;
	const char* name;
	unsigned   age;
	
public:
        Person(const char* nm, unsigned age=0);
        Person(const char* nm, int age=0);
        
	static unsigned numberOfPeople() { return numPeople; }
        void identify() const;

};

unsigned Person::numPeople = 0;
//end of Person.h

I did: 
 swig -c++ -ruby Person.i
 g++ -c Person.cpp
 g++ -c Person.cc
 g++ -c Person_wrap.cxx -I /usr/lib/ruby/1.6/i686-linux-gnu
 <all ok, till here:>
 g++ -shared Person.o Person_wrap.o -o Person.so

Trying to compile that shared lib gave me:
Person_wrap.o(.data+0x20): multiple definition of `Person::numPeople'
Person.o(.data+0x0): first defined here
collect2: ld returned 1 exit status

So SWIG interpretted numPeople as a static member function instead of as a 
static variable (class variable).

Anyway to get around this?

Phil