Change the use of integrals to chrono types as appropriate

beast/hash/hash_append.h

@@ -25,6 +25,7 @@
 #include <beast/hash/endian.h>
 #include <beast/utility/meta.h>
 #include <array>
+#include <chrono>
 #include <cstdint>
 #include <cstring>
 #include <functional>
@@ -472,6 +473,24 @@ hash_append (Hasher& h, std::shared_ptr<T> const& p) noexcept
     hash_append(h, p.get());
 }
 
+// chrono
+
+template <class Hasher, class Rep, class Period>
+inline
+void
+hash_append (Hasher& h, std::chrono::duration<Rep, Period> const& d) noexcept
+{
+    hash_append(h, d.count());
+}
+
+template <class Hasher, class Clock, class Duration>
+inline
+void
+hash_append (Hasher& h, std::chrono::time_point<Clock, Duration> const& tp) noexcept
+{
+    hash_append(h, tp.time_since_epoch());
+}
+
 // variadic
 
 template <class Hasher, class T0, class T1, class ...T>