[hist] Initialize std::atomic in test

hahnjo · hahnjo · commit 5cc079c6be12 · 2026-06-11T08:30:50.000+02:00
Before LWG 2334, in implementations only fixed in C++20 and later,
the value would be uninitialized.
diff --git a/hist/histv7/test/hist_test.hxx b/hist/histv7/test/hist_test.hxx
@@ -48,7 +48,7 @@ using ROOT::Experimental::Internal::RSliceBinIndexMapper;
 template <typename Work>
 void StressInParallel(std::size_t nThreads, Work &&w)
 {
-   std::atomic<bool> flag;
+   std::atomic<bool> flag = false;
 
    std::vector<std::thread> threads;
    for (std::size_t i = 0; i < nThreads; i++) {

Original file line number	Diff line number	Diff line change
`@@ -48,7 +48,7 @@ using ROOT::Experimental::Internal::RSliceBinIndexMapper;`
`48`	`48`	`template <typename Work>`
`49`	`49`	`void StressInParallel(std::size_t nThreads, Work &&w)`
`50`	`50`	`{`
`51`		`- std::atomic<bool> flag;`
	`51`	`+ std::atomic<bool> flag = false;`
`52`	`52`
`53`	`53`	`std::vector<std::thread> threads;`
`54`	`54`	`for (std::size_t i = 0; i < nThreads; i++) {`