[libcxx-commits] [libcxx] [libc++] Save duration/timeout locally for condition_variable waits (PR #148330)

[Louis Dionne via libcxx-commits]

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@@ -188,9 +188,10 @@ public:
   _LIBCPP_HIDE_FROM_ABI cv_status wait_until(_Lock& __lock, const chrono::time_point<_Clock, _Duration>& __t) {
     shared_ptr<mutex> __mut = __mut_;
     unique_lock<mutex> __lk(*__mut);
+    const chrono::time_point<_Clock, _Duration> __t_local = __t;
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ldionne wrote:

This is indeed a bug right now. I wonder if maybe it would be conforming to change `wait_until` to take by value today, without waiting for the Standard to say so. I think it might be conforming, assuming there is no way for that change to be observable (and I don't see how taking by value instead of `const&` is observable).

https://github.com/llvm/llvm-project/pull/148330