Further C++ improvement

[chainsawriot]

          yeah. I am eyeing on removing all of these

https://github.com/schochastics/adaR/blob/14692c751ac2fdbc97caa5b491357788d51eb7f6/R/parse.R#L20-L42

Originally posted by @chainsawriot in #47 (comment)

[chainsawriot]

@schochastics We can set this for v0.3. HEAD is feature complete and safe.

[chainsawriot]

• decode in C++ Decode in c++ #55
• Make Rcpp functions interruptible
• ? RcppParallel

[chainsawriot]

valgrind output of devtools::test()

==3850610== 
==3850610== HEAP SUMMARY:
==3850610==     in use at exit: 124,925,892 bytes in 95,588 blocks
==3850610==   total heap usage: 731,838 allocs, 636,250 frees, 654,821,627 bytes allocated
==3850610== 
==3850610== LEAK SUMMARY:
==3850610==    definitely lost: 760,087 bytes in 14,028 blocks
==3850610==    indirectly lost: 294,324 bytes in 6,872 blocks
==3850610==      possibly lost: 6,433 bytes in 98 blocks
==3850610==    still reachable: 123,865,048 bytes in 74,590 blocks
==3850610==                       of which reachable via heuristic:
==3850610==                         newarray           : 4,264 bytes in 1 blocks
==3850610==         suppressed: 0 bytes in 0 blocks
==3850610== Rerun with --leak-check=full to see details of leaked memory
==3850610== 
==3850610== For lists of detected and suppressed errors, rerun with: -s
==3850610== ERROR SUMMARY: 17908 errors from 2 contexts (suppressed: 0 from 0)

• investigate which part is causing the leak?

[chainsawriot]

valgrind --leak-check=yes points to this line

https://github.com/schochastics/adaR/blob/c9939674de621989a39af267e920e31d6f8dfb49/src/adaR.cpp#L6

Maybe we should new and delete it?