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August 2025

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New and Improved Decimal Library
by Matt Borland 02 Aug '25

02 Aug '25

It has been about 6 months since the indeterminate end of the Decimal review, but Chris and I wanted to announce the newest major version of the library (v5.0.0). What has changed? Quite a lot: Breaking Changes: - Based on bitwise comparisons with other similar libraries and database software, we have changed the internal encoding of our IEEE 754-compliant types - We spent about 3 months optimizing just back end integer types that are now used throughout the library and as the internals of decimal128_t - We have changed the type names to better match conventions: - decimalXX is now decimalXX_t - decimalXX_fast is now decimal_fastXX_t - The headers have been similarly renamed, and can now be used independently instead of requiring the monolith based on feedback in Review - Constructors have been simplified to reduce confusion Other Changes: - The doc content have been overhauled thanks to feedback from Peter Turcan and others during the review - The docs are no longer a single long page of Asciidoc; we have moved to Antora. Thanks to Joaquín and Christian for making it trivial to copy from Unordered to make that happen. - https://develop.decimal.cpp.al/ - We now support formatting with {fmt} - Benchmarks have been expanded to include GCC _Decimal types, and Intel's libbid. I think people should be pleased with the results now, since that was a huge point of contention at the end of the review - Every post-review issue John was kind enough to consolidate and open have been addressed Thanks to all those that helped make the library better than it was. Let us know if you find any new issues, or need a feature, as you try the new version. Chris and I are thinking about doing the re-review in the Fall; stay tuned. Matt

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