1 files changed, 32 insertions, 12 deletions
diff --git a/src/vZ/EquationSystem.hpp b/src/vZ/EquationSystem.hpp
index 790676c..5a50f6d 100644
--- a/src/vZ/EquationSystem.hpp
+++ b/src/vZ/EquationSystem.hpp
@@ -64,6 +64,38 @@ namespace vZ
     Traits();
   };
 
+  // Unary operators
+
+  template <std::size_t N, typename T>
+  inline EquationSystem<N, T>
+  operator+(const EquationSystem<N, T>& rhs)
+  {
+    return rhs;
+  }
+
+  template <std::size_t N, typename T>
+  inline EquationSystem<N, T>
+  operator-(const EquationSystem<N, T>& rhs)
+  {
+    EquationSystem<N, T> res;
+    for (std::size_t i = 0; i < N; ++i) {
+      res[i] = -rhs[i];
+    }
+    return res;
+  }
+
+  template <std::size_t N, typename T>
+  typename EquationSystem<N, T>::Scalar
+  abs(const EquationSystem<N, T>& es)
+  {
+    typename EquationSystem<N, T>::Scalar ret(0);
+    for (std::size_t i = 0; i < N; ++i) {
+      using std::abs;
+      ret = std::max(ret, abs(es[i]));
+    }
+    return ret;
+  }
+
   // Binary operators
 
   template <std::size_t N, typename T>
@@ -155,18 +187,6 @@ namespace vZ
     }
     return *this;
   }
-
-  template <std::size_t N, typename T>
-  typename EquationSystem<N, T>::Scalar
-  abs(const EquationSystem<N, T>& es)
-  {
-    typename EquationSystem<N, T>::Scalar ret(0);
-    for (std::size_t i = 0; i < N; ++i) {
-      using std::abs;
-      ret = std::max(ret, abs(es[i]));
-    }
-    return ret;
-  }
 }
 
 #endif // VZ_EQUATIONSYSTEM_HPP