Bound 'quantify::transposition_max' to 1 by default

src/adiar/exec_policy.h

@@ -192,7 +192,7 @@ namespace adiar
       public:
         /// \brief Default value construction.
         constexpr transposition_max()
-          : _value(std::numeric_limits<unsigned char>::max())
+          : _value(1)
         {}
 
         /// \brief Wrap an `unsigned char`