Fix build errors due to deprecations in MSVC 14.51 (Build Tools 18.6.11806.211)#4917
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Dutchman101 merged 1 commit intoMay 16, 2026
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…11806.211), which finally dropped the non-standard stdext namespace from the C++ standard library headers. Build failure was a direct result of the toolchain update: ccc5d7d
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Merging it now, because we need a new 1.7 build |
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…11806.211) (#4917) Fix build errors due to deprecations in MSVC 14.51 (Build Tools 18.6.11806.211), which finally dropped the non-standard stdext namespace from the C++ standard library headers. _Note: the below description is neatly written (high detail) as it may help other OSS projects facing sudden build errors._ MSVC Build Tools 14.51, shipped just now with Visual Studio 2026 18.6.0 on May 12, 2026, unconditionally removes the non-standard stdext namespace from the C++ standard library headers. This removal is documented in the [MSVC Build Tools 14.51 release notes](https://learn.microsoft.com/en-us/cpp/overview/what-s-new-for-msvc) under "Removed features". For our cryptopp, Windows build agents that upgraded its toolchain as per ccc5d7d, began failing with: **error C2653: 'stdext': is not a class or namespace name error C3861: 'make_checked_array_iterator': identifier not found** Two sites in cryptopp use stdext::make_checked_array_iterator and stdext::make_unchecked_array_iterator behind version guards that were only checking a lower bound, with no upper bound keeping in mind a future removal in MSVC Build Tools 14.51. Fix: guard both call sites on defined(_STDEXT_BEGIN), a macro the MSVC STL headers define when stdext is present and omit when it is absent. When the macro is not defined - as is the case with MSVC Build Tools 14.51 and later - both sites fall through to their existing raw-pointer else branches, which are functionally identical.
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Fix build errors due to deprecations in MSVC 14.51 (Build Tools 18.6.11806.211), which finally dropped the non-standard stdext namespace from the C++ standard library headers.
Note: the below description is neatly written (high detail) as it may help other OSS projects facing sudden build errors.
MSVC Build Tools 14.51, shipped just now with Visual Studio 2026 18.6.0 on May 12, 2026, unconditionally removes the non-standard stdext namespace from the C++ standard library headers. This removal is documented in the MSVC Build Tools 14.51 release notes under "Removed features". For our cryptopp, Windows build agents that upgraded its toolchain as per ccc5d7d, began failing with:
error C2653: 'stdext': is not a class or namespace name
error C3861: 'make_checked_array_iterator': identifier not found
Two sites in cryptopp use stdext::make_checked_array_iterator and stdext::make_unchecked_array_iterator behind version guards that were only checking a lower bound, with no upper bound keeping in mind a future removal in MSVC Build Tools 14.51.
Fix: guard both call sites on defined(_STDEXT_BEGIN), a macro the MSVC STL headers define when stdext is present and omit when it is absent. When the macro is not defined - as is the case with MSVC Build Tools 14.51 and later - both sites fall through to their existing raw-pointer else branches, which are functionally identical.