Function cuda_memcpy_on 

pub unsafe fn cuda_memcpy_on<const SRC_DEVICE: bool, const DST_DEVICE: bool>(
    dst: *mut c_void,
    src: *const c_void,
    size_bytes: usize,
    device_ctx: &GpuDeviceCtx,
) -> Result<(), MemCopyError>

FFI binding for cudaMemcpyAsync on an explicit stream.

Safety

Must follow the rules of the cudaMemcpyAsync function from the CUDA runtime API.