```{index} single: set_donttouchdata (PDL) ``` ```{index} single: PDL::set_donttouchdata ``` # set_donttouchdata Declare that the ndarray's storage belongs to someone else. $pdl->set_donttouchdata; $pdl->set_donttouchdata($nbytes); After this the ndarray will not free its own data when it goes away - the caller who supplied that memory is responsible for it. With a size argument, the ndarray also records that many bytes as its extent. Returns 1. This is how a memory-mapped ndarray is set up, by `set_data_by_file_map` and hence by `PDL::IO::FastRaw::mapfraw`. Setting it on an ndarray whose data PDL did allocate leaks that data.