Bridge between C++ and ruby.

README.md

Try to implement C++ and ruby Bridge.

How to use

$ ruby extconf.rb
$ make
$ ruby test.rb

extconf.rb

require 'mkmf'
have_library("stdc++")
$CXXFLAGS += '-std=c++14 -Wc++11-extensions -Wc++11-long-long'
create_makefile("foo")

foo.cpp

#include "foo.h"
#include <iostream>
#include <new>

Foo::Foo(const char* name)
{
  _init = true;
  _name = name;
}

const char* Foo::say() const
{
  std::cout << "This is foo in cpp ";
  std::cout << _name << std::endl;
  return _name;
}

static void wrap_Foo_free(Foo* p)
{
  if(p->isInit()){
    p->~Foo();
  }
  ruby_xfree(p);
}

static VALUE wrap_Foo_alloc(VALUE klass)
{
  return Data_Wrap_Struct(klass, NULL, wrap_Foo_free, ruby_xmalloc(sizeof(Foo)));
}

static VALUE wrap_Foo_init(VALUE self, VALUE _name)
{
  const char* name = StringValuePtr(_name);
  Foo* p;
  Data_Get_Struct(self, Foo, p);
  new (p) Foo(name);
  return Qnil;
}

static VALUE wrap_Foo_say(VALUE self)
{
  Foo* p;
  Data_Get_Struct(self, Foo, p);
  return rb_str_new2(p->say());
}

extern "C" void Init_foo()
{
  VALUE c = rb_define_class("Foo", rb_cObject);
  rb_define_alloc_func(c, wrap_Foo_alloc);
  rb_define_private_method(c, "initialize", RUBY_METHOD_FUNC(wrap_Foo_init), 1);
  rb_define_method(c, "say", RUBY_METHOD_FUNC(wrap_Foo_say), 0);
}

foo.h

#ifndef __FOO_H__
#define __FOO_H__

#include <ruby.h>

class Foo
{
public:
    Foo(const char* name);
    virtual ~Foo() = default;
    inline bool isInit(){ return _init; }
    const char* say() const;
private:
    bool _init;
    const char* _name;
};
#endif

test.rb

require './foo'

p Foo.new("hoge").say
p Foo.new("baz").say