How to Improve the Safety of C++ Code With a Quantities & Units Library

on YouTube ↗01h 03m

" summary

A Modern C++ quantities library claims concrete safety: mp-units implements P2981 to make unit errors fail at compile time, catches truncation when converting integers, and encodes kinds so incompatible quantities (energy vs force) refuse to mix. Examples include a 31% historical miles error in Columbus’s data and references to mishaps like the Mars Climate Orbiter. Performance stays competitive with primitives — the generated code has same assembly as doubles — but MSVC required recent bug workarounds.

AI-written summary · about

" chapters (39)

1. 0:00Introduction to CBP
2. 0:31Physical units in software
3. 1:53Impact of software bugs
4. 5:08C++ safety challenges
5. 7:01Library design goals
6. 9:23Applications of units
7. 10:16Issues in legacy code
8. 11:53Inconsistent interfaces
9. 13:52Library features
10. 15:31Library capabilities
11. 17:00Compiler support
12. 19:30Standardization efforts
13. 21:15Units library demo
14. 22:18Safety through errors
15. 24:13Stronger interface design
16. 27:37Debugging library errors
17. 28:33Performance comparisons
18. 30:03Generic interfaces
19. 30:53Practical use cases
20. 33:13Affine space support
21. 34:09Automatic conversions
22. 34:49Unit definition limits
23. 36:24Defining new units
24. 37:49International units
25. 39:15Preventing data loss
26. 40:34Value preserving casts
27. 42:54Columbus case study
28. 44:21Historical unit analysis
29. 46:56Calculating historical errors
30. 49:32Library complexity
31. 50:25Chrono comparison
32. 51:17Safe numerical access
33. 52:42Modeling complex domains
34. 53:32Quantity specification
35. 54:48Composability
36. 55:53Compile-time validation
37. 56:51Mathematical operations
38. 58:20ISO 80000 compliance
39. 59:31Conclusion and Q&A

" related talks

• 01h 30mEnhancing Safety in C++ Code With Modern C++ Quantities and Units LibraryMateusz Pusz · ACCU 2024
• 01h 02mA Physical Units Library For C++Mateusz Pusz · NDC TechTown 2021
• 01h 23mThe Power of C++ Templates With mp-units: Lessons Learned & a New Library DesignMateusz Pusz · C++ on Sea 2023
• 01h 08mA Physical Units Library For the Next C++Mateusz Pusz · CppCon 2020
• 01h 40mUsing Units, Qantities, and Dimensions in C++14Peter Sommerlad · ACCU 2016
• 01h 31mImplementing Physical Units Library for C++Mateusz Pusz · ACCU 2019
• 51mThe C++ Type System is your FriendHubert Matthews · NDC London 2017
• 01h 13mThe 10 Essential Features for the Future of C++ LibrariesMateusz Pusz · ACCU 2025