#define XST_mIV(i,v) (ST(i) = sv_2mortal(newSViv(v)) )
#define XST_mNV(i,v) (ST(i) = sv_2mortal(newSVnv(v)) )
#define XST_mPV(i,v) (ST(i) = sv_2mortal(newSVpv(v,0)))
+#define XST_mPVN(i,v,n) (ST(i) = sv_2mortal(newSVpvn(v,n)))
#define XST_mNO(i) (ST(i) = &PL_sv_no )
#define XST_mYES(i) (ST(i) = &PL_sv_yes )
#define XST_mUNDEF(i) (ST(i) = &PL_sv_undef)
#define XSRETURN_IV(v) STMT_START { XST_mIV(0,v); XSRETURN(1); } STMT_END
#define XSRETURN_NV(v) STMT_START { XST_mNV(0,v); XSRETURN(1); } STMT_END
#define XSRETURN_PV(v) STMT_START { XST_mPV(0,v); XSRETURN(1); } STMT_END
+#define XSRETURN_PVN(v) STMT_START { XST_mPVN(0,v,n); XSRETURN(1); } STMT_END
#define XSRETURN_NO STMT_START { XST_mNO(0); XSRETURN(1); } STMT_END
#define XSRETURN_YES STMT_START { XST_mYES(0); XSRETURN(1); } STMT_END
#define XSRETURN_UNDEF STMT_START { XST_mUNDEF(0); XSRETURN(1); } STMT_END