Hi everyone,
I’m trying to import a C++ library in Ruby using SWIG, but I have a
problem with namespaces and enumerators: I have a namespace “mymodule”
with a function “myfunction” which takes an element of type “myenum” as
an argument.
If I define “myfunction” and “myenum” in the same source file
“mymodule.h” everything works, but if I separate them, placing “myenum”
in “myenum.h” something odd happens: I can print the value of an element
of “myenum” via Ruby but cannot pass it as an argument to “myfunction”.
Here are the source files and the error I get:
##################
mymodule.h
##################
#ifndef MYMODULE_H
#define MYMODULE_H
#include “myenum.h”
namespace mymodule {
void myfunction(myenum);
}
#endif
################
myenum.h
################
#ifndef MYENUM_H
#define MYENUM_H
namespace mymodule {
enum myenum { A, B, C };
}
#endif
####################
mymodule.cxx
####################
#include “mymodule.h”
namespace mymodule {
void myfunction(myenum c)
{
// do nothing
}
}
##################
mymodule.i
##################
%module mymodule
%{
#include “mymodule.h”
#include “myenum.h”
using namespace mymodule;
%}
%include mymodule.h
%include myenum.h
################
myapp.rb
################
require ‘mymodule’
print "I can print Mymodule::B = ", Mymodule::B, “\n”
print “but I cannot pass it as an argument:\n”
Mymodule::myfunction(Mymodule::B)
####################
command-line
####################
$ swig -c++ -ruby mymodule.i
$ g++ -fPIC -c mymodule_wrap.cxx -I/usr/lib/ruby/1.8/x86_64-linux
$ g++ -fPIC -c mymodule.cxx
$ g++ -shared -o mymodule.so *.o
$ ruby myapp.rb
I can print Mymodule::B = 1
but I cannot pass it as an argument:
myapp.rb:7:in `myfunction’: Expected argument 0 of type myenum, but got
Fixnum 1 (TypeError)
in SWIG method ‘mymodule::myfunction’ from myapp.rb:7