Update time.tex [revert]

hanickadot · web-flow · commit de4c0070c709 · 2025-07-30T20:08:34.000+02:00
diff --git a/source/time.tex b/source/time.tex
@@ -1255,7 +1255,7 @@
 
   public:
     // \ref{time.duration.cons}, construct/copy/destroy
-    duration() = default;
+    constexpr duration() = default;
     template<class Rep2>
       constexpr explicit duration(const Rep2& r);
     template<class Rep2, class Period2>
