1 files changed, 26 insertions, 4 deletions
diff --git a/impl/Complete.hpp b/impl/Complete.hpp
index e3ec15a..336ab24 100644
--- a/impl/Complete.hpp
+++ b/impl/Complete.hpp
@@ -7,23 +7,38 @@
 
 template<typename T>
 T infinity() { }
+template<typename T>
+T unknown(const T&) { }
 
 template<typename T>
 struct Complete {
   Complete()
-    : _value(0), _infinity(false) { }
+    : _value(0), _infinity(false), _unknown(false) { }
   Complete(const T& value)
-    : _value(value), _infinity(false) { }
+    : _value(value), _infinity(false), _unknown(false) { }
   Complete(const T& value, const bool& infinity)
-    : _value(value), _infinity(infinity) {
+    : _value(value), _infinity(infinity), _unknown(false) {
     assert(value != 0 || infinity == false);
   }
   Complete(const Complete& other)
-    : _value(other._value), _infinity(other._infinity) { }
+    : _value(other._value), _infinity(other._infinity), _unknown(other._unknown) { }
+  Complete(const Complete& other, bool unknown)
+    : _value(other._value), _infinity(other._infinity), _unknown(unknown) { }
+
+  Complete asUnknown() const {
+    return Complete(*this, true);
+  }
+  Complete asKnown() const {
+    return Complete(*this, false);
+  }
+  bool isUnknown() const {
+    return _unknown;
+  }
 
   Complete& operator=(const Complete& other) {
     _value = other._value;
     _infinity = other._infinity;
+    _unknown = other._unknown;
     return *this;
   }
   Complete& operator+=(const Complete& other) {
@@ -102,6 +117,7 @@ struct Complete {
   private:
   T _value;
   bool _infinity;
+  bool _unknown;
 };
 
 template<typename Z>
@@ -114,6 +130,8 @@ std::istream& operator>>(std::istream& cin, Complete<Z>& num) {
 
 template<typename Z>
 std::ostream& operator<<(std::ostream& cout, const Complete<Z>& num) {
+  if (num._unknown)
+    cout << "(unknown)";
   if (num._infinity) {
     cout << (num._value > 0 ? "inf" : "-inf");
   } else {
@@ -126,5 +144,9 @@ template<>
 Complete<int> infinity() {
   return Complete<int>(1, true);
 }
+template<>
+Complete<int> unknown(const Complete<int>& x) {
+  return Complete<int>(x, true);
+}
 
 #endif