Issue #7299 has been updated by matz (Yukihiro Matsumoto). Status changed from Open to Feedback I considered this issue before, and had problem with how to detect non block calling block. Things go easier if & block argument is mandatory for block taking methods, but I am not doing so in near future. Do you have any good idea? Matz. ---------------------------------------- Feature #7299: Ruby should not completely ignore blocks. https://bugs.ruby-lang.org/issues/7299#change-32540 Author: marcandre (Marc-Andre Lafortune) Status: Feedback Priority: Normal Assignee: Category: core Target version: Ruby should not completely ignore blocks. const_set :Example, Class.new do p "Hello, world" end # Doesn't print anything, generate any warning nor error. To minimize any impact, Ruby should issue a warning, and in future version could even raise an error. Even unused variables provide warnings in verbose mode, and they have their use. I can't think of a case where passing a block to a builtin method that doesn't accept a block is not a programming error though. If this is approved, I volunteer to implement this. -- http://bugs.ruby-lang.org/