FEATURE_BIT 67 ruby.c #define FEATURE_BIT(bit) (1U << feature_##bit) FEATURE_BIT 150 ruby.c | FEATURE_BIT(frozen_string_literal) FEATURE_BIT 151 ruby.c | FEATURE_BIT(debug_frozen_string_literal) FEATURE_BIT 154 ruby.c (FEATURE_BIT(debug_flag_first)-1) FEATURE_BIT 156 ruby.c & ~FEATURE_BIT(gems) FEATURE_BIT 158 ruby.c & ~FEATURE_BIT(frozen_string_literal)