_is_utf8__perl_idstart is not an API function, so the short
_is_utf8__perl_idstart form cannot be used in public macros.
The long form (Perl__is_utf8__perl_idstart) must be used.
: (UTF8_IS_DOWNGRADEABLE_START(*(p))) \
? isIDFIRST_L1(TWO_BYTE_UTF8_TO_UNI(*(p), \
*((p)+1)))\
- : _is_utf8__perl_idstart(p))
+ : Perl__is_utf8__perl_idstart(aTHX_ p))
#define isIDCONT_utf8(p) generic_utf8(isWORDCHAR, is_utf8_xidcont, p)
#define isALPHA_utf8(p) generic_utf8(isALPHA, is_utf8_alpha, p)
#define isSPACE_utf8(p) generic_utf8(isSPACE, is_utf8_space, p)