#ifdef PERLIO_LAYERS
PERLVARI(Iperlio, PerlIO *,NULL)
+PERLVARI(Iknown_layers, PerlIO_list_t *,NULL)
+PERLVARI(Idef_layerlist, PerlIO_list_t *,NULL)
#endif
+PERLVARI(Iencoding, SV*, Nullsv) /* character encoding */
+
/* New variables must be added to the very end for binary compatibility.
* XSUB.h provides wrapper functions via perlapi.h that make this
* irrelevant, but not all code may be expected to #include XSUB.h. */