fix iterator invalidation issue by storing indices not iterators

[MungoG]

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[cppalliance-bot]

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2025-11-21 18:27:11 UTC

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 98.01%. Comparing base (a0d1585) to head (6c5ee63).

Additional details and impacted files

@@             Coverage Diff             @@
##           develop      #54      +/-   ##
===========================================
+ Coverage    97.97%   98.01%   +0.04%     
===========================================
  Files           12       12              
  Lines          493      505      +12     
===========================================
+ Hits           483      495      +12     
  Misses          10       10              

Files with missing lines	Coverage Δ
include/boost/buffers/slice.hpp	98.03% <100.00%> (+0.16%)	⬆️

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[ashtum]

Does this buffer type has proper test cases for move and copy operations? It's odd that it has been passing the tests before this change.