Ext++

Ext++ is a Ruby extension that provides C++ API for writing Ruby extension.

You can write your Ruby extension easier than Ruby's C API. Because Ext++'s C++ API reduces duplicated code needed for Ruby's C API.

You can use all Ruby's C API without any adapter layer. Because you can use C API directory from C++.

% gem install extpp

Here is an example to create Hello class.

Create hello.cpp:

#include <ruby.hpp> RB_BEGIN_DECLS void Init_hello(void) { rb::Class klass("Hello"); klass.define_method("initialize", [](VALUE rb_self, int argc, VALUE *argv) { VALUE rb_name; rb_scan_args(argc, argv, "1", &rb_name); rb::Object self(rb_self); self.ivar_set("@name", rb_name); return Qnil; }); klass.define_method("greet", [](VALUE rb_self) { rb::Object self(rb_self); rb::Object prefix(rb_str_new_cstr("Hello ")); auto message = prefix.send("+", {self.ivar_get("@name")}); return static_cast<VALUE>(message); }); } RB_END_DECLS

This code equals to the following Ruby code:

class Hello def initialize(name) @name = name end def greet "Hello " + @name end end

Create extconf.rb:

require "extpp" create_makefile("hello")

Create Makefile:

% ruby extconf.rb

Build this extension:

% make

Now, you can use this extension:

% ruby -r ./hello -e 'p Hello.new("me").greet' "Hello me"

Copyright (C) 2017-2021 Sutou Kouhei

The 2-Clause BSD License. See LICENSE.txt for details.