rb_sym2id         371 include/ruby/ruby.h ID rb_sym2id(VALUE);
rb_sym2id         377 include/ruby/ruby.h #define RB_SYM2ID(x) (rb_sym2id(x))
rb_sym2id         153 symbol.c           id = sym ? rb_sym2id(sym) : intern_str(str, 1);
rb_sym2id         562 symbol.c           if (sym) return rb_sym2id(sym);