make min max of semirandom device constexpr

alib2std/src/extensions/random.hpp

@@ -104,7 +104,7 @@ private:
 		 *
 		 * \return minimal value in the range of generated values
 		 */
-		result_type min() {
+		static constexpr result_type min() {
 			return 0;
 		}
@@ -114,7 +114,7 @@ private:
 		 *
 		 * \return maximal value in the range of generated values
 		 */
-		result_type max() {
+		static constexpr result_type max() {
 			return std::numeric_limits<result_type>::max() ;
 		}