Problem with implicit volume/area setting in set_endpoint() of copy parameters class

[eyalroz]

Some of the 3D copy parameters: cuda::memory::copy_parameters_t<3> structure's set_endpoint() methods on those parameters check whether the volume or area is 0 - in which case they (re)set its value to the endpoint dimensions. This is problematic behavior,, because those volumne fields may be uninitialized; and this conditional "generosity" makes the function's behavior dependent on uninitialized data. It is, perhaps, better to not set this at all, and require explicit setting via a separate call; or, alternatively, to always set this, so that if a smaller extent is desired, it must be set after the endpoint has been (re)set.

... perhaps we should have versions of the set_endpoint() (and set_source(), set_destination()) functions with and without dimensions - and have the latter force the extent and pitch, and the former not touch it.

[eyalroz]

Now, set_endpoint_untyped() always sets both the pitch and the dimensions, while set_endpoint_ptr() sets none of those two - and does not take dimensions as a parameter.