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…ed-new-delete dir_itr_imp::operator new allocates with std::malloc and operator delete releases with std::free, which is correct. GCC reports -Wmismatched-new-delete when it inlines only one half of the pair into a caller, which breaks -Werror builds (e.g. GCC 15 at -O1). Mark the operator new and both operator delete overloads BOOST_NOINLINE so the pair is treated consistently, as suggested in GCC PR 103993. Fixes boostorg#356.
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Fixes #356.
dir_itr_imp::operator newallocates withstd::mallocandoperator deletereleases withstd::free, which is correct. GCC reports-Wmismatched-new-deletewhen it inlines only one half of such a pair into a caller (the diagnostic is computed on the optimized code), so with-Werrorthis fails e.g. with GCC 15 at-O1. This is a known GCC limitation, see GCC PR 103993, where the suggested workaround is to keep the allocation and deallocation functions both inlined or both out of line.This marks
operator newand bothoperator deleteoverloadsBOOST_NOINLINE. There is no diagnostic pragma and no change to how memory is allocated or freed. It costs one non-inlined call per directory open.Testing (GCC 15.2.0, AlmaLinux 9, x86-64):
libs/filesystem/src/directory.cppondevelopwith-Wall -Werror -fsanitize=thread: unpatched fails with-Werror=mismatched-new-deleteat-O1; patched compiles cleanly at-Og,-O1,-O2and-Os(C++20 and C++26).b2 libs/filesystem/test, GCC 15,-O1 -Wall -Werror=mismatched-new-delete, C++20) builds and passes with the patch (32 passed, 0 failed).b2build of the filesystem library did not reproduce the error on unpatcheddevelopin my setup, so the single-file compile above is the evidence that the change removes the diagnostic.-O1 -fsanitize=threadbuild of a large project that failed on this error now builds, and its tests pass.🤖 Generated with Claude Code