Add gcc15,clang21,clang22 workflows to ci

[20162026]

testing inplace_vector with newer compiler version

also running Asan and Tsan for all buils feels wasteful and hella slow, furthermore I dont really see a point of running Tsan for inplace_vector at all...

[20162026]

the only warning, I have noticed occures when compiling with gcc15

27/29] "/usr/sbin/ctest" --instrument --command-type compile --target-name beman.inplace_vector.tests.modifiers --config Release --build-dir "/__w/inplace_vector/inplace_vector/build" --output tests/beman/inplace_vector/CMakeFiles/beman.inplace_vector.tests.modifiers.dir/Release/modifiers.test.cpp.o --source /__w/inplace_vector/inplace_vector/tests/beman/inplace_vector/modifiers.test.cpp --language CXX --  /usr/sbin/g++ -DCMAKE_INTDIR=\"Release\" -I/__w/inplace_vector/inplace_vector/include -I/__w/inplace_vector/inplace_vector/build/include -isystem /__w/inplace_vector/inplace_vector/build/_deps/googletest-src/googletest/include -isystem /__w/inplace_vector/inplace_vector/build/_deps/googletest-src/googletest -O3  -O3 -DNDEBUG -std=gnu++23 -MD -MT tests/beman/inplace_vector/CMakeFiles/beman.inplace_vector.tests.modifiers.dir/Release/modifiers.test.cpp.o -MF tests/beman/inplace_vector/CMakeFiles/beman.inplace_vector.tests.modifiers.dir/Release/modifiers.test.cpp.o.d -o tests/beman/inplace_vector/CMakeFiles/be
In file included from /usr/lib/gcc/x86_64-pc-linux-gnu/15/include/g++-v15/bits/ranges_algobase.h:41,
                 from /usr/lib/gcc/x86_64-pc-linux-gnu/15/include/g++-v15/numeric:95,
                 from /__w/inplace_vector/inplace_vector/tests/beman/inplace_vector/modifiers.test.cpp:1:
In function 'constexpr _OutIter std::__copy_move_a2(_InIter, _Sent, _OutIter) [with bool _IsMove = true; _InIter = NonTriviallyDefaultConstructible*; _Sent = NonTriviallyDefaultConstructible*; _OutIter = NonTriviallyDefaultConstructible*]',
    inlined from 'constexpr _OI std::__copy_move_a1(_II, _II, _OI) [with bool _IsMove = true; _II = NonTriviallyDefaultConstructible*; _OI = NonTriviallyDefaultConstructible*]' at /usr/lib/gcc/x86_64-pc-linux-gnu/15/include/g++-v15/bits/stl_algobase.h:492:42,
    inlined from 'constexpr _OI std::__copy_move_a(_II, _II, _OI) [with bool _IsMove = true; _II = NonTriviallyDefaultConstructible*; _OI = NonTriviallyDefaultConstructible*]' at /usr/lib/gcc/x86_64-pc-linux-gnu/15/include/g++-v15/bits/stl_algobase.h:500:31,
    inlined from 'constexpr _OI std::move(_II, _II, _OI) [with _II = NonTriviallyDefaultConstructible*; _OI = NonTriviallyDefaultConstructible*]' at /usr/lib/gcc/x86_64-pc-linux-gnu/15/include/g++-v15/bits/stl_algobase.h:674:38,
    inlined from 'constexpr T* beman::inplace_vector::details::inplace_vector_base<T, N>::erase(const_iterator, const_iterator) requires  movable<T> [with T = NonTriviallyDefaultConstructible; long unsigned int N = 1]' at /__w/inplace_vector/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:382:21,
    inlined from 'void {anonymous}::Modifiers_EraseRange_Test<gtest_TypeParam_>::TestBody() [with gtest_TypeParam_ = TestParam<NonTriviallyDefaultConstructible, 1>]' at /__w/inplace_vector/inplace_vector/tests/beman/inplace_vector/modifiers.test.cpp:878:21:
/usr/lib/gcc/x86_64-pc-linux-gnu/15/include/g++-v15/bits/stl_algobase.h:426:32: warning: 'void* __builtin_memmove(void*, const void*, long unsigned int)' reading between 5 and 1016 bytes from a region of size 4 [-Wstringop-overread]
  426 |               __builtin_memmove(_GLIBCXX_TO_ADDR(__result),
      |               ~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
  427 |                                 _GLIBCXX_TO_ADDR(__first),
      |                                 ~~~~~~~~~~~~~~~~~~~~~~~~~~
  428 |                                 __n * sizeof(*__first));
      |                                 ~~~~~~~~~~~~~~~~~~~~~~~
/__w/inplace_vector/inplace_vector/tests/beman/inplace_vector/modifiers.test.cpp: In member function 'void {anonymous}::Modifiers_EraseRange_Test<gtest_TypeParam_>::TestBody() [with gtest_TypeParam_ = TestParam<NonTriviallyDefaultConstructible, 1>]':
/__w/inplace_vector/inplace_vector/tests/beman/inplace_vector/modifiers.test.cpp:869:6: note: at offset 4 into source object 'device' of size 8
  869 |   IV device(reference);
      |      ^~~~~~
In function 'constexpr _OutIter std::__copy_move_a2(_InIter, _Sent, _OutIter) [with bool _IsMove = true; _InIter = Trivial*; _Sent = Trivial*; _OutIter = Trivial*]',
    inlined from 'constexpr _OI std::__copy_move_a1(_II, _II, _OI) [with bool _IsMove = true; _II = Trivial*; _OI = Trivial*]' at /usr/lib/gcc/x86_64-pc-linux-gnu/15/include/g++-v15/bits/stl_algobase.h:492:42,
    inlined from 'constexpr _OI std::__copy_move_a(_II, _II, _OI) [with bool _IsMove = true; _II = Trivial*; _OI = Trivial*]' at /usr/lib/gcc/x86_64-pc-linux-gnu/15/include/g++-v15/bits/stl_algobase.h:500:31,
    inlined from 'constexpr _OI std::move(_II, _II, _OI) [with _II = Trivial*; _OI = Trivial*]' at /usr/lib/gcc/x86_64-pc-linux-gnu/15/include/g++-v15/bits/stl_algobase.h:674:38,
    inlined from 'constexpr T* beman::inplace_vector::details::inplace_vector_base<T, N>::erase(const_iterator, const_iterator) requires  movable<T> [with T = Trivial; long unsigned int N = 1]' at /__w/inplace_vector/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:382:21,
    inlined from 'void {anonymous}::Modifiers_EraseRange_Test<gtest_TypeParam_>::TestBody() [with gtest_TypeParam_ = TestParam<Trivial, 1>]' at /__w/inplace_vector/inplace_vector/tests/beman/inplace_vector/modifiers.test.cpp:878:21:
/usr/lib/gcc/x86_64-pc-linux-gnu/15/include/g++-v15/bits/stl_algobase.h:426:32: warning: 'void* __builtin_memmove(void*, const void*, long unsigned int)' reading between 5 and 1016 bytes from a region of size 4 [-Wstringop-overread]
  426 |               __builtin_memmove(_GLIBCXX_TO_ADDR(__result),
      |               ~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
  427 |                                 _GLIBCXX_TO_ADDR(__first),
      |                                 ~~~~~~~~~~~~~~~~~~~~~~~~~~
  428 |                                 __n * sizeof(*__first));
      |                                 ~~~~~~~~~~~~~~~~~~~~~~~
/__w/inplace_vector/inplace_vector/tests/beman/inplace_vector/modifiers.test.cpp: In member function 'void {anonymous}::Modifiers_EraseRange_Test<gtest_TypeParam_>::TestBody() [with gtest_TypeParam_ = TestParam<Trivial, 1>]':
/__w/inplace_vector/inplace_vector/tests/beman/inplace_vector/modifiers.test.cpp:869:6: note: at offset 4 into source object 'device' of size 8
  869 |   IV device(reference);
      |      ^~~~~~

[20162026]

according to opus 4.7 previously mentioned gcc15 warning is false positive,

---

That's GCC 15's -Wstringop-overread firing on erase(first, last) at include/beman/inplace_vector/inplace_vector.hpp:382. With N=1, the storage is one element wide (4 or 8 bytes), but GCC can't prove last - first <= size() so it assumes the std::move source range could be up to 1016 bytes — hence "reading between 5 and 1016 bytes from a region of size 4."

Ranked, with the tradeoff that drives each choice:

1. [[assume]] in the header

[[assume(static_cast<size_type>(last - first) <= size() - static_cast<size_type>(first - begin()))]];

• For: Encodes the standard's existing precondition in the API contract. Fixes the warning for all callers. Lets the optimizer use the bound. Spec-clean — only formalizes UB the standard already grants.
• Against: Buggy precondition arithmetic could be silently optimized away. Couples to compiler analysis quality.
• Pick when: You see this as a library contract issue.

2. Localized #pragma in the header

#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wstringop-overread"
unsafe_destroy(std::move(...), end());
#pragma GCC diagnostic pop

• For: Zero codegen change, zero new UB, no optimizer coupling. Honest "known false positive" acknowledgment. Fixes for all callers.
• Against: GCC-specific (guard with #if defined(__GNUC__) && !defined(__clang__)). Disables the diagnostic at this site forever.
• Pick when: You'd rather not encode assumptions.

3. Localized #pragma in the test

• For: Header stays clean. Suppression co-located with the only known trigger.
• Against: Whack-a-mole — every future N=1 erase caller will see it again.
• Pick when: You're sure this is a one-off and don't want to touch the header.

4. Hand-rolled move loop

for (iterator src = f + (last-first), dst = f; src != end(); ++src, ++dst)
  *dst = std::move(*src);

• For: No pragma, no [[assume]], no UB strengthening, no optimizer coupling.
• Against: Loses std::move's memmove specialization for trivial T (usually re-vectorized, not guaranteed).
• Pick when: You want zero compiler-specific knobs and accept potential minor perf cost.

Recommendation

Default to #1 ([[assume]] in header) — only fix that documents the contract, helps the optimizer, aligns with the standard, and works for every caller.

Fall back to #2 (header pragma) to avoid assumption hints. Use #3 (test pragma) only if the library shouldn't change. Reach for #4 (loop) if opposed to compiler-specific knobs.

[ednolan]

Superseded by #138.