1 files changed, 42 insertions, 2 deletions
diff --git a/impl/VariableAssignment.hpp b/impl/VariableAssignment.hpp
index e41f3d8..a2d0afd 100644
--- a/impl/VariableAssignment.hpp
+++ b/impl/VariableAssignment.hpp
@@ -6,11 +6,36 @@
 template<typename T>
 struct VariableAssignment {
   VariableAssignment(unsigned int length)
-    : _length(length), _assignment(new T[length]) { }
+    : _length(length), _assignment(new T[length]) {
+    for (unsigned int i = 0; i < _length; ++i) {
+      _assignment[i] = -infinity<T>();
+    }
+  }
+  VariableAssignment(unsigned int length, const T& initial)
+    : _length(length), _assignment(new T[length]) {
+    for (unsigned int i = 0; i < _length; ++i) {
+      _assignment[i] = initial;
+    }
+  }
+  VariableAssignment(const VariableAssignment& other)
+    : _length(other._length), _assignment(new T[other._length]) {
+    for (unsigned int i = 0; i < _length; ++i) {
+      _assignment[i] = other._assignment[i];
+    }
+  }
   ~VariableAssignment() {
     delete[] _assignment;
   }
-  const T& operator[] (const Variable<T> x) const {
+  VariableAssignment& operator=(const VariableAssignment& other) {
+    delete[] _assignment;
+    _length = other._length;
+    _assignment = new T[_length];
+    for (unsigned int i = 0; i < _length; ++i) {
+      _assignment[i] = other._assignment[i];
+    }
+    return *this;
+  }
+  const T& operator[] (const Variable<T>& x) const {
     if (x.id() < 0 || x.id() >= _length) {
       throw "Array out of bounds";
     }
@@ -22,6 +47,21 @@ struct VariableAssignment {
     }
     return _assignment[x.id()];
   }
+
+  VariableAssignment<T> expand(const VariableAssignment<T>& other) {
+    return expand(other, infinity<T>());
+  }
+  VariableAssignment<T> expand(const VariableAssignment<T>& other, const T& value) {
+    VariableAssignment<T> expansion(_length);
+    for (unsigned int i = 0; i < _length; ++i) {
+      if (_assignment[i] == other._assignment[i]) {
+        expansion._assignment[i] = _assignment[i];
+      } else {
+        expansion._assignment[i] = value;
+      }
+    }
+    return expansion;
+  }
   private:
   unsigned int _length;
   T* _assignment;