rb_enc_nth        138 include/ruby/encoding.h char* rb_enc_nth(const char*, const char*, long, rb_encoding*);
rb_enc_nth        749 sprintf.c      			char *p = rb_enc_nth(RSTRING_PTR(str), RSTRING_END(str),
rb_enc_nth       8873 string.c       	(e = rb_enc_nth(p, e, len, enc)) - p == blen) {