1.1 --- a/lemon/concepts/digraph.h	Thu Feb 25 09:46:12 2021 +0100
     1.2 +++ b/lemon/concepts/digraph.h	Tue Jul 28 21:23:36 2020 +0200
     1.3 @@ -77,6 +77,12 @@
     1.4          ///
     1.5          Node(const Node&) { }
     1.6  
     1.7 +        /// Assignment operator
     1.8 +
     1.9 +        /// Assignment operator.
    1.10 +        ///
    1.11 +        const Node &operator=(const Node&) { return *this; }
    1.12 +
    1.13          /// %Invalid constructor \& conversion.
    1.14  
    1.15          /// Initializes the object to be invalid.
    1.16 @@ -126,6 +132,12 @@
    1.17          /// Copy constructor.
    1.18          ///
    1.19          NodeIt(const NodeIt& n) : Node(n) { }
    1.20 +        /// Assignment operator
    1.21 +
    1.22 +        /// Assignment operator.
    1.23 +        ///
    1.24 +        const NodeIt &operator=(const NodeIt&) { return *this; }
    1.25 +
    1.26          /// %Invalid constructor \& conversion.
    1.27  
    1.28          /// Initializes the iterator to be invalid.
    1.29 @@ -185,6 +197,12 @@
    1.30          /// Copy constructor.
    1.31          ///
    1.32          Arc(const Arc&) { }
    1.33 +        /// Assignment operator
    1.34 +
    1.35 +        /// Assignment operator.
    1.36 +        ///
    1.37 +        const Arc &operator=(const Arc&) { return *this; }
    1.38 +
    1.39          /// %Invalid constructor \& conversion.
    1.40  
    1.41          /// Initializes the object to be invalid.
    1.42 @@ -235,6 +253,11 @@
    1.43          /// Copy constructor.
    1.44          ///
    1.45          OutArcIt(const OutArcIt& e) : Arc(e) { }
    1.46 +        /// Assignment operator
    1.47 +
    1.48 +        /// Assignment operator.
    1.49 +        ///
    1.50 +        const OutArcIt &operator=(const OutArcIt&) { return *this; }
    1.51          /// %Invalid constructor \& conversion.
    1.52  
    1.53          /// Initializes the iterator to be invalid.
    1.54 @@ -301,6 +324,12 @@
    1.55          /// Copy constructor.
    1.56          ///
    1.57          InArcIt(const InArcIt& e) : Arc(e) { }
    1.58 +        /// Assignment operator
    1.59 +
    1.60 +        /// Assignment operator.
    1.61 +        ///
    1.62 +        const InArcIt &operator=(const InArcIt&) { return *this; }
    1.63 +
    1.64          /// %Invalid constructor \& conversion.
    1.65  
    1.66          /// Initializes the iterator to be invalid.
    1.67 @@ -365,6 +394,12 @@
    1.68          /// Copy constructor.
    1.69          ///
    1.70          ArcIt(const ArcIt& e) : Arc(e) { }
    1.71 +        /// Assignment operator
    1.72 +
    1.73 +        /// Assignment operator.
    1.74 +        ///
    1.75 +        const ArcIt &operator=(const ArcIt&) { return *this; }
    1.76 +
    1.77          /// %Invalid constructor \& conversion.
    1.78  
    1.79          /// Initializes the iterator to be invalid.
    1.80 @@ -521,7 +556,12 @@
    1.81          ///Copy constructor
    1.82          NodeMap(const NodeMap& nm) :
    1.83            ReferenceMap<Node, T, T&, const T&>(nm) { }
    1.84 +      public:
    1.85          ///Assignment operator
    1.86 +        NodeMap& operator=(const NodeMap&) {
    1.87 +          return *this;
    1.88 +        }
    1.89 +        ///Template Assignment operator
    1.90          template <typename CMap>
    1.91          NodeMap& operator=(const CMap&) {
    1.92            checkConcept<ReadMap<Node, T>, CMap>();
    1.93 @@ -547,6 +587,10 @@
    1.94          ArcMap(const ArcMap& em) :
    1.95            ReferenceMap<Arc, T, T&, const T&>(em) { }
    1.96          ///Assignment operator
    1.97 +        ArcMap& operator=(const ArcMap&) {
    1.98 +          return *this;
    1.99 +        }
   1.100 +        ///Template Assignment operator
   1.101          template <typename CMap>
   1.102          ArcMap& operator=(const CMap&) {
   1.103            checkConcept<ReadMap<Arc, T>, CMap>();