look into reported rchk issues

[jimhester]

Package vroom version 1.0.0
Package built using 76458/R 3.7.0; x86_64-pc-linux-gnu; 2019-05-06 13:10:42 UTC; unix   
Checked with rchk version 8de4e6e0566199e4662b2716e5acf000dd84f60b
More information at https://github.com/kalibera/cran-checks/blob/master/rchk/PROTECT.md

Function SEXPREC* vroom_vec::Extract_subset<vroom_chr>(SEXPREC*, SEXPREC*, SEXPREC*)
  [UP] unprotected variable <unnamed var:   %65 = alloca %struct.SEXPREC*, align 8> while calling allocating function std::__1::shared_ptr<std::__1::vector<unsigned long, std::__1::allocator<unsigned long> > >::~shared_ptr() vroom/src/./vroom_vec.h:95

Function SEXPREC* vroom_vec::Extract_subset<vroom_dbl>(SEXPREC*, SEXPREC*, SEXPREC*)
  [UP] unprotected variable <unnamed var:   %65 = alloca %struct.SEXPREC*, align 8> while calling allocating function std::__1::shared_ptr<std::__1::vector<unsigned long, std::__1::allocator<unsigned long> > >::~shared_ptr() vroom/src/./vroom_vec.h:95

Function SEXPREC* vroom_vec::Extract_subset<vroom_int>(SEXPREC*, SEXPREC*, SEXPREC*)
  [UP] unprotected variable <unnamed var:   %65 = alloca %struct.SEXPREC*, align 8> while calling allocating function std::__1::shared_ptr<std::__1::vector<unsigned long, std::__1::allocator<unsigned long> > >::~shared_ptr() vroom/src/./vroom_vec.h:95

Function SEXPREC* vroom_vec::Extract_subset<vroom_num>(SEXPREC*, SEXPREC*, SEXPREC*)
  [UP] unprotected variable <unnamed var:   %65 = alloca %struct.SEXPREC*, align 8> while calling allocating function std::__1::shared_ptr<std::__1::vector<unsigned long, std::__1::allocator<unsigned long> > >::~shared_ptr() vroom/src/./vroom_vec.h:95

From a brief look I am not entirely sure this is a real issue, but I will try to reproduce it and see if I can rewrite the code to avoid it.

[jimhester]

Was able to reproduce with the singularity container and tweak the code so this warning no longer occurs. 0eae9e5