COMP: Build against ITK 6 - #45
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hjmjohnson wants to merge 1 commit into
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hjmjohnson wants to merge 1 commit into
hjmjohnson wants to merge 1 commit into
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Two changes, both of which keep the module building against ITK 5.4 as well. The module pinned CMAKE_CXX_STANDARD to 14 before find_package(ITK). ITK 6 carries its own requirement on its imported targets, so the module's library compiled as C++17 regardless, but the wrapping subdirectory reads CMAKE_CXX_STANDARD directly to pick castxml's -std flag. castxml then parsed ITK 6 headers as C++14 and failed on std::is_convertible_v in itkSmartPointer.h. Take the standard from ITK_CXX_STANDARD, which both 5.4 and 6 export, and only when the caller has not already chosen one. ITK 6 also turns ITK_DISALLOW_COPY_AND_ASSIGN into a static assertion asking for ITK_DISALLOW_COPY_AND_MOVE, which ITK 5.4 defines as well.
hjmjohnson
marked this pull request as ready for review
September 22, 2026 16:05
dzenanz
approved these changes
Sep 22, 2026
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Build against ITK 6 while keeping ITK 5.4: take the C++ standard from
ITK_CXX_STANDARD(only when the caller has not set one) so castxml parses ITK 6 headers as C++17, and useITK_DISALLOW_COPY_AND_MOVE.Why the standard mattered
The module pinned
CMAKE_CXX_STANDARDto 14 beforefind_package(ITK). ITK 6's imported targets compile the library as C++17 regardless, but the wrapping readsCMAKE_CXX_STANDARDto pick castxml's-std, so castxml parsed ITK 6 headers as C++14 and failed onstd::is_convertible_vinitkSmartPointer.h.Verification
Configured with
ITK_DIRpointing at an installed ITK 6 tree (upstreammainas of 2026-09-22,ITK_WRAP_PYTHON=ON), built the module and its Python wrapping, and imported the wrapped module from Python. The module still builds against ITK 5.4.