[llvm] [STLExtras] Add a template for detecting whether a type has an equality comparison operator (PR #176429)

Mon Jan 19 10:08:39 PST 2026

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `llvm-clang-x86_64-sie-win` running on `sie-win-worker` while building `llvm` at step 7 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/46/builds/29318

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 7 (test-build-unified-tree-check-all) failure: test (failure)
...
[414/1200] Building CXX object unittests\ADT\CMakeFiles\ADTTests.dir\ImmutableListTest.cpp.obj
[415/1200] Building CXX object unittests\ADT\CMakeFiles\ADTTests.dir\ImmutableMapTest.cpp.obj
[416/1200] Building CXX object unittests\ADT\CMakeFiles\ADTTests.dir\IntrusiveRefCntPtrTest.cpp.obj
[417/1200] Building CXX object unittests\ADT\CMakeFiles\ADTTests.dir\PriorityWorklistTest.cpp.obj
[418/1200] Building CXX object unittests\ADT\CMakeFiles\ADTTests.dir\PointerEmbeddedIntTest.cpp.obj
[419/1200] Building CXX object unittests\ADT\CMakeFiles\ADTTests.dir\IntervalMapTest.cpp.obj
[420/1200] Building CXX object unittests\ADT\CMakeFiles\ADTTests.dir\MappedIteratorTest.cpp.obj
[421/1200] Building CXX object unittests\ADT\CMakeFiles\ADTTests.dir\PagedVectorTest.cpp.obj
[422/1200] Building CXX object unittests\ADT\CMakeFiles\ADTTests.dir\ScopedHashTableTest.cpp.obj
[423/1200] Building CXX object unittests\ADT\CMakeFiles\ADTTests.dir\STLExtrasTest.cpp.obj
FAILED: unittests/ADT/CMakeFiles/ADTTests.dir/STLExtrasTest.cpp.obj 
C:\bin\ccache.exe C:\PROGRA~2\MICROS~1\2019\BUILDT~1\VC\Tools\MSVC\1429~1.301\bin\HostX64\x64\cl.exe  /nologo /TP -DLLVM_BUILD_STATIC -DUNICODE -D_CRT_NONSTDC_NO_DEPRECATE -D_CRT_NONSTDC_NO_WARNINGS -D_CRT_SECURE_NO_DEPRECATE -D_CRT_SECURE_NO_WARNINGS -D_GLIBCXX_ASSERTIONS -D_HAS_EXCEPTIONS=0 -D_SCL_SECURE_NO_DEPRECATE -D_SCL_SECURE_NO_WARNINGS -D_UNICODE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -Iunittests\ADT -IZ:\b\llvm-clang-x86_64-sie-win\llvm-project\llvm\unittests\ADT -Iinclude -IZ:\b\llvm-clang-x86_64-sie-win\llvm-project\llvm\include -IZ:\b\llvm-clang-x86_64-sie-win\llvm-project\third-party\unittest\googletest\include -IZ:\b\llvm-clang-x86_64-sie-win\llvm-project\third-party\unittest\googlemock\include /DWIN32 /D_WINDOWS   /Zc:inline /Zc:preprocessor /Zc:__cplusplus /Oi /bigobj /permissive- /W4 -wd4141 -wd4146 -wd4244 -wd4267 -wd4291 -wd4351 -wd4456 -wd4457 -wd4458 -wd4459 -wd4503 -wd4624 -wd4722 -wd4100 -wd4127 -wd4512 -wd4505 -wd4610 -wd4510 -wd4702 -wd4245 -wd4706 -wd4310 -wd4701 -wd4703 -wd4389 -wd4611 -wd4805 -wd4204 -wd4577 -wd4091 -wd4592 -wd4319 -wd4709 -wd5105 -wd4324 -wd4251 -wd4275 -w14062 -we4238 /Gw /O2 /Ob2  -MD -UNDEBUG /EHs-c- /GR- -std:c++17 /showIncludes /Founittests\ADT\CMakeFiles\ADTTests.dir\STLExtrasTest.cpp.obj /Fdunittests\ADT\CMakeFiles\ADTTests.dir\ /FS -c Z:\b\llvm-clang-x86_64-sie-win\llvm-project\llvm\unittests\ADT\STLExtrasTest.cpp
Z:\b\llvm-clang-x86_64-sie-win\llvm-project\llvm\include\llvm/ADT/STLExtras.h(167): warning C4308: negative integral constant converted to unsigned type
Z:\b\llvm-clang-x86_64-sie-win\llvm-project\llvm\unittests\ADT\STLExtrasTest.cpp(1596): note: while evaluating constexpr function 'llvm::addEnumValues'
Z:\b\llvm-clang-x86_64-sie-win\llvm-project\llvm\unittests\ADT\STLExtrasTest.cpp(1799): error C2607: static assertion failed
[424/1200] Building CXX object unittests\ADT\CMakeFiles\ADTTests.dir\LazyAtomicPointerTest.cpp.obj
[425/1200] Building CXX object tools\clang\unittests\Interpreter\CMakeFiles\ClangReplInterpreterTests.dir\InterpreterExtensionsTest.cpp.obj
[426/1200] Building CXX object unittests\ADT\CMakeFiles\ADTTests.dir\IntervalTreeTest.cpp.obj
[427/1200] Building CXX object unittests\ADT\CMakeFiles\ADTTests.dir\DynamicAPIntTest.cpp.obj
[428/1200] Building CXX object unittests\ADT\CMakeFiles\ADTTests.dir\PointerIntPairTest.cpp.obj
[429/1200] Building CXX object unittests\ADT\CMakeFiles\ADTTests.dir\PackedVectorTest.cpp.obj
[430/1200] Building CXX object unittests\ADT\CMakeFiles\ADTTests.dir\MapVectorTest.cpp.obj
[431/1200] Building CXX object unittests\ADT\CMakeFiles\ADTTests.dir\PointerSumTypeTest.cpp.obj
[432/1200] Building CXX object unittests\ADT\CMakeFiles\ADTTests.dir\IteratorTest.cpp.obj
[433/1200] Building CXX object unittests\ADT\CMakeFiles\ADTTests.dir\SCCIteratorTest.cpp.obj
[434/1200] Building CXX object unittests\ADT\CMakeFiles\ADTTests.dir\RewriteBufferTest.cpp.obj
[435/1200] Building CXX object unittests\ADT\CMakeFiles\ADTTests.dir\DenseMapTest.cpp.obj
[436/1200] Building CXX object unittests\ADT\CMakeFiles\ADTTests.dir\PostOrderIteratorTest.cpp.obj
[437/1200] Building CXX object unittests\ADT\CMakeFiles\ADTTests.dir\RangeAdapterTest.cpp.obj
[438/1200] Building CXX object tools\clang\unittests\Sema\CMakeFiles\SemaTests.dir\SemaNoloadLookupTest.cpp.obj
[439/1200] Building CXX object unittests\ADT\CMakeFiles\ADTTests.dir\ScopeExitTest.cpp.obj
[440/1200] Building CXX object unittests\ADT\CMakeFiles\ADTTests.dir\PointerUnionTest.cpp.obj
[441/1200] Building CXX object unittests\ADT\CMakeFiles\ADTTests.dir\STLForwardCompatTest.cpp.obj
[442/1200] Building CXX object unittests\ADT\CMakeFiles\ADTTests.dir\SimpleIListTest.cpp.obj
[443/1200] Building CXX object unittests\ADT\CMakeFiles\ADTTests.dir\SmallVectorExtrasTest.cpp.obj
[444/1200] Building CXX object unittests\ADT\CMakeFiles\ADTTests.dir\SetVectorTest.cpp.obj
[445/1200] Building CXX object unittests\ADT\CMakeFiles\ADTTests.dir\SmallStringTest.cpp.obj
[446/1200] Building CXX object tools\clang\unittests\Sema\CMakeFiles\SemaTests.dir\CodeCompleteTest.cpp.obj
[447/1200] Building CXX object unittests\ADT\CMakeFiles\ADTTests.dir\SetOperationsTest.cpp.obj
[448/1200] Building CXX object unittests\ADT\CMakeFiles\ADTTests.dir\SmallSetTest.cpp.obj
[449/1200] Building CXX object unittests\ADT\CMakeFiles\ADTTests.dir\SmallPtrSetTest.cpp.obj
[450/1200] Building CXX object unittests\ADT\CMakeFiles\ADTTests.dir\SequenceTest.cpp.obj
[451/1200] Building CXX object tools\clang\unittests\Format\CMakeFiles\FormatTests.dir\TokenAnnotatorTest.cpp.obj
[452/1200] Building CXX object tools\clang\unittests\Sema\CMakeFiles\SemaTests.dir\HeuristicResolverTest.cpp.obj
[453/1200] Building CXX object unittests\ADT\CMakeFiles\ADTTests.dir\RadixTreeTest.cpp.obj
[454/1200] Building CXX object tools\clang\unittests\Interpreter\CMakeFiles\ClangReplInterpreterTests.dir\InterpreterTest.cpp.obj
[455/1200] Building CXX object tools\clang\unittests\Interpreter\CMakeFiles\ClangReplInterpreterTests.dir\IncrementalProcessingTest.cpp.obj
[456/1200] Building CXX object tools\clang\unittests\Interpreter\CMakeFiles\ClangReplInterpreterTests.dir\CodeCompletionTest.cpp.obj
ninja: build stopped: subcommand failed.

```

</details>

https://github.com/llvm/llvm-project/pull/176429