+#ifndef sv_catpvn_nomg
+# define sv_catpvn_nomg sv_catpvn
+#endif
+
+#ifndef HvNAME_get
+# define HvNAME_get(H) HvNAME(H)
+#endif
+
+#ifndef HvNAMELEN_get
+# define HvNAMELEN_get(H) strlen(HvNAME_get(H))
+#endif
+
+#ifndef SvIS_FREED
+# define SvIS_FREED(sv) ((sv)->sv_flags == SVTYPEMASK)
+#endif
+
+#define I_HAS_PERL(R, V, S) (PERL_REVISION > (R) || (PERL_REVISION == (R) && (PERL_VERSION > (V) || (PERL_VERSION == (V) && (PERL_SUBVERSION >= (S))))))
+
+#if I_HAS_PERL(5, 10, 0) || defined(PL_parser)
+# ifndef PL_lex_inwhat
+# define PL_lex_inwhat PL_parser->lex_inwhat
+# endif
+# ifndef PL_linestr
+# define PL_linestr PL_parser->linestr
+# endif
+# ifndef PL_bufptr
+# define PL_bufptr PL_parser->bufptr
+# endif
+# ifndef PL_oldbufptr
+# define PL_oldbufptr PL_parser->oldbufptr
+# endif
+#else
+# ifndef PL_lex_inwhat
+# define PL_lex_inwhat PL_Ilex_inwhat
+# endif
+# ifndef PL_linestr
+# define PL_linestr PL_Ilinestr
+# endif
+# ifndef PL_bufptr
+# define PL_bufptr PL_Ibufptr
+# endif
+# ifndef PL_oldbufptr
+# define PL_oldbufptr PL_Ioldbufptr
+# endif
+#endif
+
+/* ... Thread safety and multiplicity ...................................... */
+
+#ifndef I_MULTIPLICITY
+# if defined(MULTIPLICITY) || defined(PERL_IMPLICIT_CONTEXT)
+# define I_MULTIPLICITY 1
+# else
+# define I_MULTIPLICITY 0
+# endif
+#endif
+#if I_MULTIPLICITY && !defined(tTHX)
+# define tTHX PerlInterpreter*
+#endif
+
+#if I_MULTIPLICITY && defined(USE_ITHREADS) && defined(dMY_CXT) && defined(MY_CXT) && defined(START_MY_CXT) && defined(MY_CXT_INIT) && (defined(MY_CXT_CLONE) || defined(dMY_CXT_SV))
+# define I_THREADSAFE 1
+# ifndef MY_CXT_CLONE
+# define MY_CXT_CLONE \
+ dMY_CXT_SV; \
+ my_cxt_t *my_cxtp = (my_cxt_t*)SvPVX(newSV(sizeof(my_cxt_t)-1)); \
+ Copy(INT2PTR(my_cxt_t*, SvUV(my_cxt_sv)), my_cxtp, 1, my_cxt_t); \
+ sv_setuv(my_cxt_sv, PTR2UV(my_cxtp))
+# endif
+#else
+# define I_THREADSAFE 0
+# undef dMY_CXT
+# define dMY_CXT dNOOP
+# undef MY_CXT
+# define MY_CXT indirect_globaldata
+# undef START_MY_CXT
+# define START_MY_CXT STATIC my_cxt_t MY_CXT;
+# undef MY_CXT_INIT
+# define MY_CXT_INIT NOOP
+# undef MY_CXT_CLONE
+# define MY_CXT_CLONE NOOP
+#endif
+
+/* --- Helpers ------------------------------------------------------------- */
+
+/* ... Pointer table ....................................................... */
+
+#define PTABLE_NAME ptable
+#define PTABLE_VAL_FREE(V) if ((V) && !SvIS_FREED((SV *) (V))) SvREFCNT_dec(V)
+
+#define pPTBL pTHX
+#define pPTBL_ pTHX_
+#define aPTBL aTHX
+#define aPTBL_ aTHX_
+
+#include "ptable.h"
+
+#define ptable_store(T, K, V) ptable_store(aTHX_ (T), (K), (V))
+#define ptable_clear(T) ptable_clear(aTHX_ (T))
+#define ptable_free(T) ptable_free(aTHX_ (T))