Define return of iso_calendar as ctypedef

Author: mgmarino

pandas/_libs/tslibs/ccalendar.pxd

@@ -2,10 +2,11 @@ from cython cimport Py_ssize_t
 
 from numpy cimport int64_t, int32_t
 
+ctypedef (int32_t, int32_t, int32_t) iso_calendar_t
 
 cdef int dayofweek(int y, int m, int d) nogil
 cdef bint is_leapyear(int64_t year) nogil
 cpdef int32_t get_days_in_month(int year, Py_ssize_t month) nogil
 cpdef int32_t get_week_of_year(int year, int month, int day) nogil
-cpdef (int32_t, int32_t, int32_t) get_iso_calendar(int year, int month, int day) nogil
+cpdef iso_calendar_t get_iso_calendar(int year, int month, int day) nogil
 cpdef int32_t get_day_of_year(int year, int month, int day) nogil

pandas/_libs/tslibs/ccalendar.pyx

@@ -159,7 +159,7 @@ cpdef int32_t get_week_of_year(int year, int month, int day) nogil:
 
 @cython.wraparound(False)
 @cython.boundscheck(False)
-cpdef (int32_t, int32_t, int32_t) get_iso_calendar(int year, int month, int day) nogil:
+cpdef iso_calendar_t get_iso_calendar(int year, int month, int day) nogil:
     """
     Return the year, week, and day of year corresponding to ISO 8601
 

pandas/_libs/tslibs/fields.pyx

@@ -15,7 +15,7 @@ from pandas._libs.tslibs.ccalendar import (
     get_locale_names, MONTHS_FULL, DAYS_FULL, DAY_SECONDS)
 from pandas._libs.tslibs.ccalendar cimport (
     get_days_in_month, is_leapyear, dayofweek, get_week_of_year,
-    get_day_of_year, get_iso_calendar)
+    get_day_of_year, get_iso_calendar, iso_calendar_t)
 from pandas._libs.tslibs.np_datetime cimport (
     npy_datetimestruct, pandas_timedeltastruct, dt64_to_dtstruct,
     td64_to_tdstruct)
@@ -683,7 +683,7 @@ def build_isocalendar_sarray(const int64_t[:] dtindex):
         Py_ssize_t i, count = len(dtindex)
         npy_datetimestruct dts
         ndarray[int32_t] iso_years, iso_weeks, days
-        (int32_t, int32_t, int32_t) ret_val
+        iso_calendar_t ret_val
 
     sa_dtype = [
         ("year", "i4"),