Hi! Why Regexp.union('/../') trying to convert string with directly call rb_check_regexp_type(arg) (re.c:3139) instead of rb_reg_s_try_convert (re.c:3122)? I think second variant would be more correct, and i would be able to rewrite Regexp.try_convert in my code for changing behavior as i need.
For example: i have the code where was implemented String#to_regexp which breaks default behavior of Regexp.union and i got incorrect regexp. But i can't (for some reasons) to rewrite to_regexp method. Yes, stupid example, but it's real situation.
That makes sense.
I think it's spec that Regexp.union internally convert arguments with to_regexp, but it is undocumented behavior. I think it's a documentation issue.
This issue was solved with changeset r43061.
Alexander, thank you for reporting this issue.
Your contribution to Ruby is greatly appreciated.
May Ruby be with you.
re.c: [DOC] arguments of Regexp::union receive #to_regexp [Bug #8205]