Which FL_USERx are open to extension libraries?
Often the following failure occurs in
RBasic support for regular objects supports copying the flags from one object over to the other FAILED Expected 81920 == 33636352 to be truthy but was false /tmp/ruby/v3/src/trunk/spec/ruby/optional/capi/shared/rbasic.rb:71:in `block (2 levels) in <top (required)>' /tmp/ruby/v3/src/trunk/spec/ruby/optional/capi/rbasic_spec.rb:8:in `<top (required)>'
81920 == 0x14000
33636352 == 0x2014000
FL_USER13, which is used as
This flag is set when any
Object instance has some amount of instance variables.
In this particular case, it is possible to fix just by excluding the bit.
But, the question is which flags are open to extension libraries.
My guess is these flags are available for
T_DATA classes, but not for