How to get the size of “_cl_devide_id” struct in openCL?

cl_device_id is defined as “typedef struct _cl_device_id *cl_device_id”.

In the openCL method clGetDeviceIDs, “devices” parameter is of the type “cl_device_id *” and returns a pointer to the list of devices available.

I’m trying to pass the whole struct using memcpy to another variable. For which I need to know the size of the “_cl_device_id” struct.