+/* Generic, or stub layer functions */
+
+PERL_EXPORT_C IV PerlIOBase_binmode(pTHX_ PerlIO *f);
+PERL_EXPORT_C void PerlIOBase_clearerr(pTHX_ PerlIO *f);
+PERL_EXPORT_C IV PerlIOBase_close(pTHX_ PerlIO *f);
+PERL_EXPORT_C PerlIO * PerlIOBase_dup(pTHX_ PerlIO *f, PerlIO *o, CLONE_PARAMS *param, int flags);
+PERL_EXPORT_C IV PerlIOBase_eof(pTHX_ PerlIO *f);
+PERL_EXPORT_C IV PerlIOBase_error(pTHX_ PerlIO *f);
+PERL_EXPORT_C IV PerlIOBase_fileno(pTHX_ PerlIO *f);
+PERL_EXPORT_C void PerlIOBase_flush_linebuf(pTHX);
+PERL_EXPORT_C IV PerlIOBase_noop_fail(pTHX_ PerlIO *f);
+PERL_EXPORT_C IV PerlIOBase_noop_ok(pTHX_ PerlIO *f);
+PERL_EXPORT_C IV PerlIOBase_popped(pTHX_ PerlIO *f);
+PERL_EXPORT_C IV PerlIOBase_pushed(pTHX_ PerlIO *f, const char *mode, SV *arg, PerlIO_funcs *tab);
+PERL_EXPORT_C SSize_t PerlIOBase_read(pTHX_ PerlIO *f, void *vbuf, Size_t count);
+PERL_EXPORT_C void PerlIOBase_setlinebuf(pTHX_ PerlIO *f);
+PERL_EXPORT_C SSize_t PerlIOBase_unread(pTHX_ PerlIO *f, const void *vbuf, Size_t count);
+
+/* Buf */
+PERL_EXPORT_C Size_t PerlIOBuf_bufsiz(pTHX_ PerlIO *f);
+PERL_EXPORT_C IV PerlIOBuf_close(pTHX_ PerlIO *f);
+PERL_EXPORT_C PerlIO * PerlIOBuf_dup(pTHX_ PerlIO *f, PerlIO *o, CLONE_PARAMS *param, int flags);
+PERL_EXPORT_C IV PerlIOBuf_fill(pTHX_ PerlIO *f);
+PERL_EXPORT_C IV PerlIOBuf_flush(pTHX_ PerlIO *f);
+PERL_EXPORT_C STDCHAR * PerlIOBuf_get_base(pTHX_ PerlIO *f);
+PERL_EXPORT_C SSize_t PerlIOBuf_get_cnt(pTHX_ PerlIO *f);
+PERL_EXPORT_C STDCHAR * PerlIOBuf_get_ptr(pTHX_ PerlIO *f);
+PERL_EXPORT_C PerlIO * PerlIOBuf_open(pTHX_ PerlIO_funcs *self, PerlIO_list_t *layers, IV n, const char *mode, int fd, int imode, int perm, PerlIO *old, int narg, SV **args);
+PERL_EXPORT_C IV PerlIOBuf_popped(pTHX_ PerlIO *f);
+PERL_EXPORT_C IV PerlIOBuf_pushed(pTHX_ PerlIO *f, const char *mode, SV *arg, PerlIO_funcs *tab);
+PERL_EXPORT_C SSize_t PerlIOBuf_read(pTHX_ PerlIO *f, void *vbuf, Size_t count);
+PERL_EXPORT_C IV PerlIOBuf_seek(pTHX_ PerlIO *f, Off_t offset, int whence);
+PERL_EXPORT_C void PerlIOBuf_set_ptrcnt(pTHX_ PerlIO *f, STDCHAR * ptr, SSize_t cnt);
+PERL_EXPORT_C Off_t PerlIOBuf_tell(pTHX_ PerlIO *f);
+PERL_EXPORT_C SSize_t PerlIOBuf_unread(pTHX_ PerlIO *f, const void *vbuf, Size_t count);
+PERL_EXPORT_C SSize_t PerlIOBuf_write(pTHX_ PerlIO *f, const void *vbuf, Size_t count);
+
+/* Crlf */
+PERL_EXPORT_C IV PerlIOCrlf_binmode(pTHX_ PerlIO *f);
+PERL_EXPORT_C IV PerlIOCrlf_flush(pTHX_ PerlIO *f);
+PERL_EXPORT_C SSize_t PerlIOCrlf_get_cnt(pTHX_ PerlIO *f);
+PERL_EXPORT_C IV PerlIOCrlf_pushed(pTHX_ PerlIO *f, const char *mode, SV *arg, PerlIO_funcs *tab);
+PERL_EXPORT_C void PerlIOCrlf_set_ptrcnt(pTHX_ PerlIO *f, STDCHAR * ptr, SSize_t cnt);
+PERL_EXPORT_C SSize_t PerlIOCrlf_unread(pTHX_ PerlIO *f, const void *vbuf, Size_t count);
+PERL_EXPORT_C SSize_t PerlIOCrlf_unread(pTHX_ PerlIO *f, const void *vbuf, Size_t count);
+PERL_EXPORT_C SSize_t PerlIOCrlf_write(pTHX_ PerlIO *f, const void *vbuf, Size_t count);
+
+/* Mmap */
+PERL_EXPORT_C IV PerlIOMmap_close(pTHX_ PerlIO *f);
+PERL_EXPORT_C PerlIO * PerlIOMmap_dup(pTHX_ PerlIO *f, PerlIO *o, CLONE_PARAMS *param, int flags);
+PERL_EXPORT_C IV PerlIOMmap_fill(pTHX_ PerlIO *f);
+PERL_EXPORT_C IV PerlIOMmap_flush(pTHX_ PerlIO *f);
+PERL_EXPORT_C STDCHAR * PerlIOMmap_get_base(pTHX_ PerlIO *f);
+PERL_EXPORT_C IV PerlIOMmap_map(pTHX_ PerlIO *f);
+PERL_EXPORT_C IV PerlIOMmap_unmap(pTHX_ PerlIO *f);
+PERL_EXPORT_C SSize_t PerlIOMmap_unread(pTHX_ PerlIO *f, const void *vbuf, Size_t count);
+PERL_EXPORT_C SSize_t PerlIOMmap_write(pTHX_ PerlIO *f, const void *vbuf, Size_t count);
+
+/* Pending */
+PERL_EXPORT_C IV PerlIOPending_close(pTHX_ PerlIO *f);
+PERL_EXPORT_C IV PerlIOPending_fill(pTHX_ PerlIO *f);
+PERL_EXPORT_C IV PerlIOPending_flush(pTHX_ PerlIO *f);
+PERL_EXPORT_C IV PerlIOPending_pushed(pTHX_ PerlIO *f, const char *mode, SV *arg, PerlIO_funcs *tab);
+PERL_EXPORT_C SSize_t PerlIOPending_read(pTHX_ PerlIO *f, void *vbuf, Size_t count);
+PERL_EXPORT_C IV PerlIOPending_seek(pTHX_ PerlIO *f, Off_t offset, int whence);
+PERL_EXPORT_C void PerlIOPending_set_ptrcnt(pTHX_ PerlIO *f, STDCHAR * ptr, SSize_t cnt);
+
+/* Pop */
+PERL_EXPORT_C IV PerlIOPop_pushed(pTHX_ PerlIO *f, const char *mode, SV *arg, PerlIO_funcs *tab);
+
+/* Raw */
+PERL_EXPORT_C PerlIO * PerlIORaw_open(pTHX_ PerlIO_funcs *self, PerlIO_list_t *layers, IV n, const char *mode, int fd, int imode, int perm, PerlIO *old, int narg, SV **args);
+PERL_EXPORT_C IV PerlIORaw_pushed(pTHX_ PerlIO *f, const char *mode, SV *arg, PerlIO_funcs *tab);
+
+/* Stdio */
+PERL_EXPORT_C void PerlIOStdio_clearerr(pTHX_ PerlIO *f);
+PERL_EXPORT_C IV PerlIOStdio_close(pTHX_ PerlIO *f);
+PERL_EXPORT_C PerlIO * PerlIOStdio_dup(pTHX_ PerlIO *f, PerlIO *o, CLONE_PARAMS *param, int flags);
+PERL_EXPORT_C IV PerlIOStdio_eof(pTHX_ PerlIO *f);
+PERL_EXPORT_C IV PerlIOStdio_error(pTHX_ PerlIO *f);
+PERL_EXPORT_C IV PerlIOStdio_fileno(pTHX_ PerlIO *f);
+PERL_EXPORT_C IV PerlIOStdio_fill(pTHX_ PerlIO *f);
+PERL_EXPORT_C IV PerlIOStdio_flush(pTHX_ PerlIO *f);
+PERL_EXPORT_C STDCHAR * PerlIOStdio_get_base(pTHX_ PerlIO *f);
+PERL_EXPORT_C char * PerlIOStdio_mode(const char *mode, char *tmode);
+PERL_EXPORT_C PerlIO * PerlIOStdio_open(pTHX_ PerlIO_funcs *self, PerlIO_list_t *layers, IV n, const char *mode, int fd, int imode, int perm, PerlIO *f, int narg, SV **args);
+PERL_EXPORT_C IV PerlIOStdio_pushed(pTHX_ PerlIO *f, const char *mode, SV *arg, PerlIO_funcs *tab);
+PERL_EXPORT_C SSize_t PerlIOStdio_read(pTHX_ PerlIO *f, void *vbuf, Size_t count);
+PERL_EXPORT_C IV PerlIOStdio_seek(pTHX_ PerlIO *f, Off_t offset, int whence);
+PERL_EXPORT_C void PerlIOStdio_setlinebuf(pTHX_ PerlIO *f);
+PERL_EXPORT_C Off_t PerlIOStdio_tell(pTHX_ PerlIO *f);
+PERL_EXPORT_C SSize_t PerlIOStdio_unread(pTHX_ PerlIO *f, const void *vbuf, Size_t count);
+PERL_EXPORT_C SSize_t PerlIOStdio_write(pTHX_ PerlIO *f, const void *vbuf, Size_t count);
+
+/* Unix */
+PERL_EXPORT_C IV PerlIOUnix_close(pTHX_ PerlIO *f);
+PERL_EXPORT_C PerlIO * PerlIOUnix_dup(pTHX_ PerlIO *f, PerlIO *o, CLONE_PARAMS *param, int flags);
+PERL_EXPORT_C IV PerlIOUnix_fileno(pTHX_ PerlIO *f);
+PERL_EXPORT_C int PerlIOUnix_oflags(const char *mode);
+PERL_EXPORT_C PerlIO * PerlIOUnix_open(pTHX_ PerlIO_funcs *self, PerlIO_list_t *layers, IV n, const char *mode, int fd, int imode, int perm, PerlIO *f, int narg, SV **args);
+PERL_EXPORT_C IV PerlIOUnix_pushed(pTHX_ PerlIO *f, const char *mode, SV *arg, PerlIO_funcs *tab);
+PERL_EXPORT_C SSize_t PerlIOUnix_read(pTHX_ PerlIO *f, void *vbuf, Size_t count);
+PERL_EXPORT_C int PerlIOUnix_refcnt_dec(int fd);
+PERL_EXPORT_C void PerlIOUnix_refcnt_inc(int fd);
+PERL_EXPORT_C IV PerlIOUnix_seek(pTHX_ PerlIO *f, Off_t offset, int whence);
+PERL_EXPORT_C Off_t PerlIOUnix_tell(pTHX_ PerlIO *f);
+PERL_EXPORT_C SSize_t PerlIOUnix_write(pTHX_ PerlIO *f, const void *vbuf, Size_t count);
+
+/* Utf8 */
+PERL_EXPORT_C IV PerlIOUtf8_pushed(pTHX_ PerlIO *f, const char *mode, SV *arg, PerlIO_funcs *tab);