Add unit test for torch_tensor_get_device_index on CUDA device

src/test/unit/CMakeLists.txt

@@ -14,3 +14,7 @@ add_pfunit_ctest(test_tensor_interrogation
   TEST_SOURCES test_tensor_interrogation.pf LINK_LIBRARIES FTorch::ftorch)
 add_pfunit_ctest(test_operator_overloads
   TEST_SOURCES test_tensor_operator_overloads.pf LINK_LIBRARIES FTorch::ftorch)
+if(ENABLE_CUDA)
+  add_pfunit_ctest(test_operator_overloads_cuda
+    TEST_SOURCES test_tensor_operator_overloads_cuda.pf LINK_LIBRARIES FTorch::ftorch)
+endif()

src/test/unit/test_tensor_interrogation.pf

@@ -1,4 +1,4 @@
-!| Unit tests for FTorch subroutines that interrogate tensors.
+!| Unit tests for FTorch subroutines that interrogate tensors on the CPU.
 !
 !  * License
 !    FTorch is released under an MIT license.

src/test/unit/test_tensor_interrogation_cuda.pf

@@ -0,0 +1,45 @@
+!| Unit tests for FTorch subroutines that interrogate tensors on a CUDA device.
+!
+!  * License
+!    FTorch is released under an MIT license.
+!    See the [LICENSE](https://github.com/Cambridge-ICCS/FTorch/blob/main/LICENSE)
+!    file for details.
+module test_tensor_interrogation_cuda
+
+  implicit none
+
+  public
+
+contains
+
+  ! Unit test for the torch_tensor_get_device_index function applied to a tensor on a CUDA device
+  @test
+  subroutine test_torch_tensor_get_device_index_default()
+    use funit
+    use ftorch, only: torch_kFloat32, torch_kCPU, torch_tensor, torch_tensor_delete &
+                      torch_tensor_empty, torch_tensor_get_device_index
+    use iso_c_binding, only: c_int64_t
+
+    implicit none
+
+    type(torch_tensor) :: tensor
+    integer, parameter :: ndims = 1
+    integer(c_int64_t), parameter, dimension(ndims) :: tensor_shape = [1]
+    integer, parameter :: dtype = torch_kFloat32
+    integer, parameter :: device_type = torch_kCUDA
+    integer, parameter :: expected = 0
+
+    ! Create an empty tensor on the CPU with the default device index
+    call torch_tensor_empty(tensor, ndims, tensor_shape, dtype, device_type)
+
+    ! Check that torch_tensor_get_device_index can get the device index
+    if (expected /= torch_tensor_get_device_index(tensor)) then
+      call torch_tensor_delete(tensor)
+      print *, "Error :: torch_tensor_get_device_index returned incorrect CUDA device index"
+      stop 999
+    end if
+    call torch_tensor_delete(tensor)
+
+  end subroutine test_torch_tensor_get_device_index_default
+
+end module test_tensor_interrogation_cuda