```ruby
require 'fiddle'
require 'rbconfig'

basename = "librusty_blank.#{RbConfig::CONFIG['DLEXT']}"
library = Fiddle.dlopen(File.join(File.dirname(__FILE__), basename))
func = Fiddle::Function.new(library['init_rusty_blank'],
                            [], Fiddle::TYPE_VOIDP)
func.call
```

Fix dlext on OSX when using the gem
user
```ruby
require 'fiddle'
require 'rbconfig'

ext = RbConfig::CONFIG['DLEXT'] == 'bundle' ? 'dylib' : RbConfig::CONFIG['DLEXT']
basename = "librusty_blank.#{ext}"
library = Fiddle.dlopen(File.join(File.dirname(__FILE__), basename))
func = Fiddle::Function.new(library['init_rusty_blank'],
                            [], Fiddle::TYPE_VOIDP)
func.call
```
assistant