# tag: cpp
cdef extern from "curiously_recurring_template_pattern_GH1458_suport.h":
cdef cppclass Base[T, Derived]:
Base(T)
Derived half()
T calculate()
cdef cppclass Square[T](Base[T, Square[T]]):
Square(T)
cdef cppclass Cube[T](Base[T, Cube[T]]):
Cube(T)
def test_derived(int x):
"""
>>> test_derived(5)
(6.25, 8)
"""
try:
square_double = new Square[double](x)
cube_int = new Cube[int](x)
return square_double.half().calculate(), cube_int.half().calculate()
finally:
del square_double, cube_int