Block C++98 unexpected() from being restored in C++23 mode - #2709
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Stephan T. Lavavej (StephanTLavavej) merged 1 commit intoMay 9, 2022
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Mirrored as internal MSVC-PR-397684. This has associated VCRuntime changes and a higher-than-normal chance of encountering issues in old test suites (although my local test run passed), hence the mirror all by itself. |
Igor Zhukov (fsb4000)
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C++98's
unexpected()was removed by C++17, then C++23 reused the identifier for<expected>'sunexpected<E>(being implemented in #2643).We support escape hatches for restoring Standard-removed machinery, but we need to avoid this conflict. Instead of limiting what C++23 provides, we should simply disable this escape hatch when it conflicts with the Standard. (Note that C++98
unexpected()and its related functions weren't very useful, and MSVC never properly implemented them, thus this is mostly relevant for library test suites. It's a very different situation thanauto_ptr, for example.)This PR will be paired with internal changes to VCRuntime, as its
<eh.h>definesunexpected()et al. in the global scope, and we need to prevent that conflict too. We can complete this PR independently of #2643.