+=for apidoc Am|SV*|newSVpvn_utf8|NULLOK const char* s|STRLEN len|U32 utf8
+
+Creates a new SV and copies a string into it. If utf8 is true, calls
+C<SvUTF8_on> on the new SV. Implemented as a wrapper around C<newSVpvn_flags>.
+
+=cut
+*/
+
+#define newSVpvn_utf8(s, len, u) newSVpvn_flags((s), (len), (u) ? SVf_UTF8 : 0)
+
+/*
+=for apidoc Am|void|SvOOK_offset|NN SV*sv|STRLEN len
+
+Reads into I<len> the offset from SvPVX back to the true start of the
+allocated buffer, which will be non-zero if C<sv_chop> has been used to
+efficiently remove characters from start of the buffer. Implemented as a
+macro, which takes the address of I<len>, which must be of type C<STRLEN>.
+Evaluates I<sv> more than once. Sets I<len> to 0 if C<SvOOK(sv)> is false.
+
+=cut
+*/
+
+#ifdef DEBUGGING
+/* Does the bot know something I don't?
+10:28 <@Nicholas> metabatman
+10:28 <+meta> Nicholas: crash
+*/
+# define SvOOK_offset(sv, offset) STMT_START { \
+ assert(sizeof(offset) == sizeof(STRLEN)); \
+ if (SvOOK(sv)) { \
+ const U8 *crash = (U8*)SvPVX_const(sv); \
+ offset = *--crash; \
+ if (!offset) { \
+ crash -= sizeof(STRLEN); \
+ Copy(crash, (U8 *)&offset, sizeof(STRLEN), U8); \
+ } \
+ { \
+ /* Validate the preceding buffer's sentinels to \
+ verify that no-one is using it. */ \
+ const U8 *const bonk = (U8 *) SvPVX_const(sv) - offset; \
+ while (crash > bonk) { \
+ --crash; \
+ assert (*crash == (U8)PTR2UV(crash)); \
+ } \
+ } \
+ } else { \
+ offset = 0; \
+ } \
+ } STMT_END
+#else
+ /* This is the same code, but avoids using any temporary variables: */
+# define SvOOK_offset(sv, offset) STMT_START { \
+ assert(sizeof(offset) == sizeof(STRLEN)); \
+ if (SvOOK(sv)) { \
+ offset = ((U8*)SvPVX_const(sv))[-1]; \
+ if (!offset) { \
+ Copy(SvPVX_const(sv) - 1 - sizeof(STRLEN), \
+ (U8 *)&offset, sizeof(STRLEN), U8); \
+ } \
+ } else { \
+ offset = 0; \
+ } \
+ } STMT_END
+#endif
+
+#define newIO() MUTABLE_IO(newSV_type(SVt_PVIO))
+
+/*