fix(any_write_sink): accept mutable buffer sequences in write

[sgerbino]

ConstBufferSequence admits mutable sequences, but write windowed them through buffer_param, whose span<mutable_buffer> cannot convert to the type-erased write_(span<const_buffer const>), so calls such as write(make_buffer(some_string)) failed to instantiate. Use const_buffer_param, as write_eof already does.

[cppalliance-bot]

An automated preview of the documentation is available at https://370.capy.prtest3.cppalliance.org/index.html

If more commits are pushed to the pull request, the docs will rebuild at the same URL.

2026-07-23 13:58:56 UTC

[cppalliance-bot]

GCOVR code coverage report https://370.capy.prtest3.cppalliance.org/gcovr/index.html
LCOV code coverage report https://370.capy.prtest3.cppalliance.org/genhtml/index.html
Coverage Diff Report https://370.capy.prtest3.cppalliance.org/diff-report/index.html

Build time: 2026-07-23 14:15:44 UTC

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 98.36%. Comparing base (49b2db9) to head (c33f2f6).
⚠️ Report is 2 commits behind head on develop.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop     #370      +/-   ##
===========================================
+ Coverage    98.18%   98.36%   +0.18%     
===========================================
  Files          152      152              
  Lines         8246     8260      +14     
===========================================
+ Hits          8096     8125      +29     
+ Misses         150      135      -15     

Flag	Coverage Δ
linux	98.39% <ø> (+0.23%)	⬆️

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Files with missing lines	Coverage Δ
include/boost/capy/io/any_write_sink.hpp	98.09% <ø> (ø)

... and 3 files with indirect coverage changes

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