Fix 80-bit long double hex formatting

[mborland]

Closes: #154

[codecov[bot]]

Codecov Report

Attention: 1 lines in your changes are missing coverage. Please review.

Comparison is base (51fc3f4) 88.62% compared to head (547b0ad) 88.64%.

Additional details and impacted files

[](https://app.codecov.io/gh/boostorg/charconv/pull/159?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=boostorg) ```diff @@ Coverage Diff @@ ## develop #159 +/- ## =========================================== + Coverage 88.62% 88.64% +0.01% =========================================== Files 63 64 +1 Lines 8141 8162 +21 =========================================== + Hits 7215 7235 +20 - Misses 926 927 +1 ``` | [Files](https://app.codecov.io/gh/boostorg/charconv/pull/159?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=boostorg) | Coverage Δ | | |---|---|---| | [test/github\_issue\_154.cpp](https://app.codecov.io/gh/boostorg/charconv/pull/159?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=boostorg#diff-dGVzdC9naXRodWJfaXNzdWVfMTU0LmNwcA==) | `100.00% <100.00%> (ø)` | | | [test/to\_chars\_float\_STL\_comp.cpp](https://app.codecov.io/gh/boostorg/charconv/pull/159?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=boostorg#diff-dGVzdC90b19jaGFyc19mbG9hdF9TVExfY29tcC5jcHA=) | `100.00% <100.00%> (ø)` | | | [src/to\_chars\_float\_impl.hpp](https://app.codecov.io/gh/boostorg/charconv/pull/159?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=boostorg#diff-c3JjL3RvX2NoYXJzX2Zsb2F0X2ltcGwuaHBw) | `94.82% <94.11%> (-0.30%)` | :arrow_down: | ... and [1 file with indirect coverage changes](https://app.codecov.io/gh/boostorg/charconv/pull/159/indirect-changes?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=boostorg) ------ [Continue to review full report in Codecov by Sentry](https://app.codecov.io/gh/boostorg/charconv/pull/159?src=pr&el=continue&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=boostorg). > **Legend** - [Click here to learn more](https://docs.codecov.io/docs/codecov-delta?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=boostorg) > `Δ = absolute (impact)`, `ø = not affected`, `? = missing data` > Powered by [Codecov](https://app.codecov.io/gh/boostorg/charconv/pull/159?src=pr&el=footer&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=boostorg). Last update [51fc3f4...547b0ad](https://app.codecov.io/gh/boostorg/charconv/pull/159?src=pr&el=lastupdated&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=boostorg). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=boostorg).