SYMBOL_FLAG       259 include/ruby/ruby.h #define SYMBOL_P(x) (((VALUE)(x)&~(~(VALUE)0<<RUBY_SPECIAL_SHIFT))==SYMBOL_FLAG)
SYMBOL_FLAG       260 include/ruby/ruby.h #define ID2SYM(x) (((VALUE)(x)<<RUBY_SPECIAL_SHIFT)|SYMBOL_FLAG)