register_fstring  241 string.c       static VALUE register_fstring(VALUE str);
register_fstring  311 string.c           fstr = register_fstring(str);
register_fstring  366 string.c           return register_fstring(setup_fake_str(&fake_str, ptr, len, ENCINDEX_US_ASCII));
register_fstring  373 string.c           return register_fstring(rb_setup_fake_str(&fake_str, ptr, len, enc));