numpy: fix compatibility issue with old versions < 1.16.0

CMakeLists.txt

@@ -82,6 +82,10 @@ endif()
 set(PYTHON_EXPORT_DEPENDENCY ON)
 findpython(REQUIRED)
 
+if(NUMPY_VERSION VERSION_LESS "1.16.0")
+  set(NUMPY_WITH_BROKEN_UFUNC_SUPPORT)
+endif()
+
 if(WIN32)
   link_directories(${PYTHON_LIBRARY_DIRS})
   # # Set default Windows build paths SET(CMAKE_LIBRARY_OUTPUT_DIRECTORY

unittest/CMakeLists.txt

@@ -32,7 +32,10 @@ add_lib_unit_test(include)
 if(NOT ${EIGEN3_VERSION} VERSION_LESS "3.2.0")
   add_lib_unit_test(eigen_ref)
 endif()
-add_lib_unit_test(user_type)
+
+if(NOT NUMPY_WITH_BROKEN_UFUNC_SUPPORT)
+  add_lib_unit_test(user_type)
+endif()
 add_lib_unit_test(std_vector)
 
 add_python_unit_test("py-matrix" "unittest/python/test_matrix.py" "unittest")
@@ -43,8 +46,11 @@ add_python_unit_test("py-return-by-ref" "unittest/python/test_return_by_ref.py"
                      "unittest")
 add_python_unit_test("py-eigen-ref" "unittest/python/test_eigen_ref.py"
                      "unittest")
-add_python_unit_test("py-user-type" "unittest/python/test_user_type.py"
-                     "unittest")
+
+if(NOT NUMPY_WITH_BROKEN_UFUNC_SUPPORT)
+  add_python_unit_test("py-user-type" "unittest/python/test_user_type.py"
+                       "unittest")
+endif()
 
 add_python_unit_test("py-switch" "unittest/python/test_switch.py"
                      "python;unittest")