Fix eval multiple (arrayfire#16)

* Fix eval multiple. Refactor backend

* Fix to list comprehaension

Author: roaffix

arrayfire_wrapper/_backend.py

@@ -49,20 +49,13 @@ def _get_backend_path_config() -> _BackendPathConfig:
     platform_name = platform.system()
     cuda_found = False
 
-    # try to use user provided AF_PATH if explicitly set
-    try:
-        af_path = Path(os.environ["AF_PATH"])
-        af_is_user_path = True
-    except KeyError:
-        af_path = None
-        af_is_user_path = False
+    # Try to use user provided AF_PATH if explicitly set
+    af_path = os.environ.get("AF_PATH", None)
+    af_is_user_path = af_path is not None
 
-    try:
-        cuda_path = Path(os.environ["CUDA_PATH"])
-    except KeyError:
-        cuda_path = None
+    cuda_path = os.environ.get("CUDA_PATH", None)
 
-    # try to find default arrayfire installation paths
+    # Try to find default arrayfire installation paths
     if platform_name == _SupportedPlatforms.windows.value or _SupportedPlatforms.is_cygwin(platform_name):
         if platform_name == _SupportedPlatforms.windows.value:
             # HACK Supressing crashes caused by missing dlls

arrayfire_wrapper/lib/create_and_modify_array/manage_array.py

@@ -93,7 +93,9 @@ def eval_multiple(num: int, /, *arrs: AFArray) -> None:
     """
     source: https://arrayfire.org/docs/group__c__api__mat.htm#ga9e08f4cda2471a477d2fa91c2356f72c
     """
-    call_from_clib(eval_multiple.__name__, ctypes.c_int(num), ctypes.pointer(arrs))
+    ctypes_arrs = (ctypes.c_void_p * num)(*[arr for arr in arrs])
+
+    call_from_clib(eval_multiple.__name__, ctypes.c_int(num), ctypes.pointer(ctypes_arrs))
     return None