yield in ERB without rails

Question

How can I use yield for template inheritance in erb? I want to use erb in a plain ruby CGI script and want to use a base template and subtemplate like it Rails wit

Answer 1

I wrote about adding this to the Standard Library's ERB here http://hostiledeveloper.com/2015/05/28/working-with-templates-in-ruby-erb.html

It's surprisingly a pain in the butt.