json_object_i
Rather than checking the class we can check the type. This is very subtly different for String subclasses, but I think it's OK. We also save on checking the type again in the fast path. https://github.com/flori/json/commit/772a0201ab
rb_ary_freeze
String#match?
String#=~
PTY.spawn
start_with?
Gem::Platform.local