Fix fmt formatters outputting -0 for negative zero

Michael Teschrequested to merge
fix/fmt-neg-zero into master

Summary

  • Normalize IEEE -0.0 to +0.0 before formatting in both fmt::formatter<std::complex<T>> and fmt::formatter<duals::dual<T>>
  • complex(-0.0, 0.0) now formats as 0 instead of -0, etc.
  • Added complex_neg_zero and dual_neg_zero test cases
  • Bump version to 0.7.3

Test plan

  • All 31 libfmt tests pass (29 existing + 2 new neg-zero tests)

Merge request reports