implemen generic Min() and Max() functions

inspired by
https://stackoverflow.com/questions/23815138/implementing-variadic-min-max-functions

src/wrappers.hpp

@@ -28,6 +28,7 @@
 #include <sstream>
 #include <string>
 #include <type_traits>
+#include <utility>
 #include <vector>
 #include <Eigen/Core>
 #include <boost/lexical_cast.hpp>
@@ -357,6 +358,36 @@ double MaxAbsValue(const Eigen::MatrixBase<Derived>& x)
    return x.cwiseAbs().maxCoeff();
 }
 
+template<typename T>
+T Max(T&&t)
+{
+   return std::forward<T>(t);
+}
+
+template<typename T0, typename T1, typename... Ts>
+typename std::common_type<T0, T1, Ts...>::type Max(T0&& val1, T1&& val2, Ts&&... vs)
+{
+   if (val2 < val1)
+      return Max(val1, std::forward<Ts>(vs)...);
+   else
+      return Max(val2, std::forward<Ts>(vs)...);
+}
+
+template<typename T>
+T Min(T&&t)
+{
+   return std::forward<T>(t);
+}
+
+template<typename T0, typename T1, typename... Ts>
+typename std::common_type<T0, T1, Ts...>::type Min(T0&& val1, T1&& val2, Ts&&... vs)
+{
+   if (val2 < val1)
+      return Min(val2, std::forward<Ts>(vs)...);
+   else
+      return Min(val1, std::forward<Ts>(vs)...);
+}
+
 inline int Sign(double x)
 {
    return (x >= 0.0 ? 1 : -1);

test/test_wrappers.cpp

@@ -517,3 +517,33 @@ BOOST_AUTO_TEST_CASE(test_Im_Eigen_Matrix)
    BOOST_CHECK_EQUAL(im2(1,0), 0.);
    BOOST_CHECK_EQUAL(im2(1,1), 10.0);
 }
+
+BOOST_AUTO_TEST_CASE(test_Min)
+{
+   BOOST_CHECK_EQUAL(Min(0.), 0.);
+   BOOST_CHECK_EQUAL(Min(1.), 1.);
+   BOOST_CHECK_EQUAL(Min(-1), -1);
+
+   BOOST_CHECK_EQUAL(Min(0.,1.), 0.);
+   BOOST_CHECK_EQUAL(Min(1.,0.), 0.);
+   BOOST_CHECK_EQUAL(Min(1,0.), 0.);
+   BOOST_CHECK_EQUAL(Min(1.,0), 0.);
+
+   BOOST_CHECK_EQUAL(Min(-1,0,1), -1);
+   BOOST_CHECK_EQUAL(Min(-1.,0.,1.), -1.);
+}
+
+BOOST_AUTO_TEST_CASE(test_Max)
+{
+   BOOST_CHECK_EQUAL(Max(0.), 0.);
+   BOOST_CHECK_EQUAL(Max(1.), 1.);
+   BOOST_CHECK_EQUAL(Max(-1), -1);
+
+   BOOST_CHECK_EQUAL(Max(0.,1.), 1.);
+   BOOST_CHECK_EQUAL(Max(1.,0.), 1.);
+   BOOST_CHECK_EQUAL(Max(1,0.), 1.);
+   BOOST_CHECK_EQUAL(Max(1.,0), 1.);
+
+   BOOST_CHECK_EQUAL(Max(-1,0,1), 1);
+   BOOST_CHECK_EQUAL(Max(-1.,0.,1.), 1.);
+}