Fix gcc 9 deprecated copy warnings in antistable.

[Romain-Geissler-1A]

Hi,

Without this, when using boost container's flat_map/flat_set, I am having depecated copy warnings in gcc 9. If I declare the copy constructor private (or deleted) then it does not compile anymore, so I assume copy constructor is really needed.

Cheers, Romain

[codecov[bot]]

Codecov Report

Merging #24 into develop will decrease coverage by 0.52%. The diff coverage is 100%.

@@             Coverage Diff             @@
##           develop      #24      +/-   ##
===========================================
- Coverage     72.1%   71.57%   -0.53%     
===========================================
  Files           28       28              
  Lines         1814     1819       +5     
  Branches       612      623      +11     
===========================================
- Hits          1308     1302       -6     
- Misses         127      130       +3     
- Partials       379      387       +8

Impacted Files	Coverage Δ
include/boost/move/algo/predicate.hpp	100% <100%> (ø)	:arrow_up:
include/boost/move/algo/detail/merge.hpp	79.53% <0%> (-3.18%)	:arrow_down:
...ude/boost/move/algo/detail/adaptive_sort_merge.hpp	64.16% <0%> (+0.13%)	:arrow_up:

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update 756c964...68d57d8. Read the comment docs.

[igaztanaga]

Thanks