StephanTLavavej opened a new pull request #12317: URL: https://github.com/apache/arrow/pull/12317
As explained in ARROW-15520, these unqualified calls to `format()` are ambiguous in the C++20 Standard. The `using`-declaration `using arrow_vendored::date::format;` makes the compiler consider the desired overload, but it doesn't automatically win. Argument-Dependent Lookup also considers `std::format()` because the arguments are `std::chrono::duration` types (and `<chrono>` includes `<format>` in MSVC's implementation). A very recent change to `std::format()`'s signature in a C++20 Defect Report makes it an equally good match as the desired `arrow_vendored::date::format()` overload, so the compiler emits an ambiguity error. The fix is simple, although slightly verbose - the code simply needs to explicitly qualify each call, in order to defend against Argument-Dependent Lookup. The fix is also perfectly backwards-compatible (i.e. it works in previous Standard versions, and with all other platforms). (Also as mentioned in ARROW-15520, although this requires building Apache Arrow with non-default settings to use the latest C++ Standard version, this change is good for future-proofing and will make it easier for the MSVC team to continue validation that prevents toolset regressions that could affect Apache Arrow and other projects.) -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
