Question

To initialize a class from my library I’m doing this:

VALUE obj = rb_funcall(rb_path2class("MyGem::ClassName"),
                rb_intern("new"), 2, arg1, arg2);

It feels like a lot of that boilerplate code could be condensed to a macro like:

VALUE obj = CLASS_INIT("MyGem::ClassName", 2, arg1, arg2)

Or is that just something I’d have to write myself if it bothered me that much, repeating funcall, path2class and intern?

Answer 1

It doesn’t seem to be documented in Ruby’s README.ext but there is a function I have used in my Ruby extension called rb_class_new_instance. The prototype is basically:

rb_class_new_instance(argc, argv, klass);

It is used in StringIO.open:

http://www.ruby-doc.org/stdlib-1.9.3/libdoc/stringio/rdoc/StringIO.html

You can see how I use it here:

https://github.com/DavidEGrayson/ruby-usb-pro/blob/master/ext/device_handle.c