Significant improvements to error messages

[mborland]

Closes: #115
Closes: #116
Closes: #117

[cppalliance-bot]

An automated preview of the documentation is available at https://118.safe-numbers.prtest3.cppalliance.org/libs/safe_numbers/doc/html/index.html

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

2026-02-25 22:24:05 UTC

[codecov]

Codecov Report

❌ Patch coverage is 66.49746% with 66 lines in your changes missing coverage. Please review.
✅ Project coverage is 97.7%. Comparing base (f313c56) to head (6e0b86e).
⚠️ Report is 25 commits behind head on develop.

Files with missing lines	Patch %	Lines
...ost/safe_numbers/detail/unsigned_integer_basis.hpp	45.6%	49 Missing ⚠️
include/boost/safe_numbers/bounded_integers.hpp	86.4%	12 Missing ⚠️
examples/basic_usage_stacktrace.cpp	72.8%	2 Missing and 1 partial ⚠️
examples/basic_bounded_usage.cpp	75.0%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff            @@
##           develop    #118     +/-   ##
=========================================
- Coverage     98.5%   97.7%   -0.8%     
=========================================
  Files          104     106      +2     
  Lines         7119    7280    +161     
  Branches      2634    2684     +50     
=========================================
+ Hits          7011    7109     +98     
- Misses          42     103     +61     
- Partials        66      68      +2     

Files with missing lines	Coverage Δ
examples/basic_bounded_usage.cpp	75.0% <75.0%> (ø)
examples/basic_usage_stacktrace.cpp	72.8% <72.8%> (ø)
include/boost/safe_numbers/bounded_integers.hpp	89.0% <86.4%> (-11.0%)	⬇️
...ost/safe_numbers/detail/unsigned_integer_basis.hpp	85.6% <45.6%> (-9.8%)	⬇️

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