1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/lemon/concept/sym_graph.h Thu Nov 04 20:24:59 2004 +0000
1.3 @@ -0,0 +1,653 @@
1.4 +/* -*- C++ -*-
1.5 + * src/lemon/concept/graph.h - Part of LEMON, a generic C++ optimization library
1.6 + *
1.7 + * Copyright (C) 2004 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
1.8 + * (Egervary Combinatorial Optimization Research Group, EGRES).
1.9 + *
1.10 + * Permission to use, modify and distribute this software is granted
1.11 + * provided that this copyright notice appears in all copies. For
1.12 + * precise terms see the accompanying LICENSE file.
1.13 + *
1.14 + * This software is provided "AS IS" with no warranty of any kind,
1.15 + * express or implied, and with no claim as to its suitability for any
1.16 + * purpose.
1.17 + *
1.18 + */
1.19 +
1.20 +#ifndef LEMON_CONCEPT_SYM_GRAPH_H
1.21 +#define LEMON_CONCEPT_SYM_GRAPH_H
1.22 +
1.23 +///\ingroup concept
1.24 +///\file
1.25 +///\brief Declaration of SymGraph.
1.26 +
1.27 +#include <lemon/invalid.h>
1.28 +#include <lemon/concept/graph.h>
1.29 +#include <lemon/concept/maps.h>
1.30 +
1.31 +namespace lemon {
1.32 + namespace concept {
1.33 +
1.34 + /// \addtogroup concept
1.35 + /// @{
1.36 +
1.37 + /// An empty static graph class.
1.38 +
1.39 + /// This class provides all the common features of a symmetric
1.40 + /// graph structure, however completely without implementations and
1.41 + /// real data structures behind the interface.
1.42 + /// All graph algorithms should compile with this class, but it will not
1.43 + /// run properly, of course.
1.44 + ///
1.45 + /// It can be used for checking the interface compatibility,
1.46 + /// or it can serve as a skeleton of a new symmetric graph structure.
1.47 + ///
1.48 + /// Also, you will find here the full documentation of a certain graph
1.49 + /// feature, the documentation of a real symmetric graph imlementation
1.50 + /// like @ref SymListGraph or
1.51 + /// @ref lemon::SymSmartGraph will just refer to this structure.
1.52 + class StaticSymGraph
1.53 + {
1.54 + public:
1.55 + /// Defalult constructor.
1.56 +
1.57 + /// Defalult constructor.
1.58 + ///
1.59 + StaticSymGraph() { }
1.60 + ///Copy consructor.
1.61 +
1.62 +// ///\todo It is not clear, what we expect from a copy constructor.
1.63 +// ///E.g. How to assign the nodes/edges to each other? What about maps?
1.64 +// StaticGraph(const StaticGraph& g) { }
1.65 +
1.66 + /// The base type of node iterators,
1.67 + /// or in other words, the trivial node iterator.
1.68 +
1.69 + /// This is the base type of each node iterator,
1.70 + /// thus each kind of node iterator converts to this.
1.71 + /// More precisely each kind of node iterator should be inherited
1.72 + /// from the trivial node iterator.
1.73 + class Node {
1.74 + public:
1.75 + /// Default constructor
1.76 +
1.77 + /// @warning The default constructor sets the iterator
1.78 + /// to an undefined value.
1.79 + Node() { }
1.80 + /// Copy constructor.
1.81 +
1.82 + /// Copy constructor.
1.83 + ///
1.84 + Node(const Node&) { }
1.85 +
1.86 + /// Invalid constructor \& conversion.
1.87 +
1.88 + /// This constructor initializes the iterator to be invalid.
1.89 + /// \sa Invalid for more details.
1.90 + Node(Invalid) { }
1.91 + /// Equality operator
1.92 +
1.93 + /// Two iterators are equal if and only if they point to the
1.94 + /// same object or both are invalid.
1.95 + bool operator==(Node) const { return true; }
1.96 +
1.97 + /// Inequality operator
1.98 +
1.99 + /// \sa operator==(Node n)
1.100 + ///
1.101 + bool operator!=(Node) const { return true; }
1.102 +
1.103 + ///Comparison operator.
1.104 +
1.105 + ///This is a strict ordering between the nodes.
1.106 + ///
1.107 + ///This ordering can be different from the order in which NodeIt
1.108 + ///goes through the nodes.
1.109 + ///\todo Possibly we don't need it.
1.110 + bool operator<(Node) const { return true; }
1.111 + };
1.112 +
1.113 + /// This iterator goes through each node.
1.114 +
1.115 + /// This iterator goes through each node.
1.116 + /// Its usage is quite simple, for example you can count the number
1.117 + /// of nodes in graph \c g of type \c Graph like this:
1.118 + /// \code
1.119 + /// int count=0;
1.120 + /// for (Graph::NodeIt n(g); n!=INVALID; ++n) ++count;
1.121 + /// \endcode
1.122 + class NodeIt : public Node {
1.123 + public:
1.124 + /// Default constructor
1.125 +
1.126 + /// @warning The default constructor sets the iterator
1.127 + /// to an undefined value.
1.128 + NodeIt() { }
1.129 + /// Copy constructor.
1.130 +
1.131 + /// Copy constructor.
1.132 + ///
1.133 + NodeIt(const NodeIt&) { }
1.134 + /// Invalid constructor \& conversion.
1.135 +
1.136 + /// Initialize the iterator to be invalid.
1.137 + /// \sa Invalid for more details.
1.138 + NodeIt(Invalid) { }
1.139 + /// Sets the iterator to the first node.
1.140 +
1.141 + /// Sets the iterator to the first node of \c g.
1.142 + ///
1.143 + NodeIt(const StaticSymGraph& g) { }
1.144 + /// Node -> NodeIt conversion.
1.145 +
1.146 + /// Sets the iterator to the node of \c g pointed by the trivial
1.147 + /// iterator n.
1.148 + /// This feature necessitates that each time we
1.149 + /// iterate the edge-set, the iteration order is the same.
1.150 + NodeIt(const StaticSymGraph& g, const Node& n) { }
1.151 + /// Next node.
1.152 +
1.153 + /// Assign the iterator to the next node.
1.154 + ///
1.155 + NodeIt& operator++() { return *this; }
1.156 + };
1.157 +
1.158 +
1.159 + /// The base type of the symmetric edge iterators.
1.160 +
1.161 + /// The base type of the symmetric edge iterators.
1.162 + ///
1.163 + class SymEdge {
1.164 + public:
1.165 + /// Default constructor
1.166 +
1.167 + /// @warning The default constructor sets the iterator
1.168 + /// to an undefined value.
1.169 + SymEdge() { }
1.170 + /// Copy constructor.
1.171 +
1.172 + /// Copy constructor.
1.173 + ///
1.174 + SymEdge(const SymEdge&) { }
1.175 + /// Initialize the iterator to be invalid.
1.176 +
1.177 + /// Initialize the iterator to be invalid.
1.178 + ///
1.179 + SymEdge(Invalid) { }
1.180 + /// Equality operator
1.181 +
1.182 + /// Two iterators are equal if and only if they point to the
1.183 + /// same object or both are invalid.
1.184 + bool operator==(SymEdge) const { return true; }
1.185 + /// Inequality operator
1.186 +
1.187 + /// \sa operator==(Node n)
1.188 + ///
1.189 + bool operator!=(SymEdge) const { return true; }
1.190 + ///Comparison operator.
1.191 +
1.192 + ///This is a strict ordering between the nodes.
1.193 + ///
1.194 + ///This ordering can be different from the order in which NodeIt
1.195 + ///goes through the nodes.
1.196 + ///\todo Possibly we don't need it.
1.197 + bool operator<(SymEdge) const { return true; }
1.198 + };
1.199 +
1.200 +
1.201 + /// The base type of the edge iterators.
1.202 +
1.203 + /// The base type of the edge iterators.
1.204 + ///
1.205 + class Edge : public SymEdge {
1.206 + public:
1.207 + /// Default constructor
1.208 +
1.209 + /// @warning The default constructor sets the iterator
1.210 + /// to an undefined value.
1.211 + Edge() { }
1.212 + /// Copy constructor.
1.213 +
1.214 + /// Copy constructor.
1.215 + ///
1.216 + Edge(const Edge&) { }
1.217 + /// Initialize the iterator to be invalid.
1.218 +
1.219 + /// Initialize the iterator to be invalid.
1.220 + ///
1.221 + Edge(Invalid) { }
1.222 + /// Equality operator
1.223 +
1.224 + /// Two iterators are equal if and only if they point to the
1.225 + /// same object or both are invalid.
1.226 + bool operator==(Edge) const { return true; }
1.227 + /// Inequality operator
1.228 +
1.229 + /// \sa operator==(Node n)
1.230 + ///
1.231 + bool operator!=(Edge) const { return true; }
1.232 + ///Comparison operator.
1.233 +
1.234 + ///This is a strict ordering between the nodes.
1.235 + ///
1.236 + ///This ordering can be different from the order in which NodeIt
1.237 + ///goes through the nodes.
1.238 + ///\todo Possibly we don't need it.
1.239 + bool operator<(Edge) const { return true; }
1.240 + };
1.241 +
1.242 + /// This iterator goes trough the outgoing edges of a node.
1.243 +
1.244 + /// This iterator goes trough the \e outgoing edges of a certain node
1.245 + /// of a graph.
1.246 + /// Its usage is quite simple, for example you can count the number
1.247 + /// of outgoing edges of a node \c n
1.248 + /// in graph \c g of type \c Graph as follows.
1.249 + /// \code
1.250 + /// int count=0;
1.251 + /// for (Graph::OutEdgeIt e(g, n); e!=INVALID; ++e) ++count;
1.252 + /// \endcode
1.253 +
1.254 + class OutEdgeIt : public Edge {
1.255 + public:
1.256 + /// Default constructor
1.257 +
1.258 + /// @warning The default constructor sets the iterator
1.259 + /// to an undefined value.
1.260 + OutEdgeIt() { }
1.261 + /// Copy constructor.
1.262 +
1.263 + /// Copy constructor.
1.264 + ///
1.265 + OutEdgeIt(const OutEdgeIt&) { }
1.266 + /// Initialize the iterator to be invalid.
1.267 +
1.268 + /// Initialize the iterator to be invalid.
1.269 + ///
1.270 + OutEdgeIt(Invalid) { }
1.271 + /// This constructor sets the iterator to first outgoing edge.
1.272 +
1.273 + /// This constructor set the iterator to the first outgoing edge of
1.274 + /// node
1.275 + ///@param n the node
1.276 + ///@param g the graph
1.277 + OutEdgeIt(const StaticSymGraph& g, const Node& n) { }
1.278 + /// Edge -> OutEdgeIt conversion
1.279 +
1.280 + /// Sets the iterator to the value of the trivial iterator \c e.
1.281 + /// This feature necessitates that each time we
1.282 + /// iterate the edge-set, the iteration order is the same.
1.283 + OutEdgeIt(const StaticSymGraph& g, const Edge& e) { }
1.284 + ///Next outgoing edge
1.285 +
1.286 + /// Assign the iterator to the next
1.287 + /// outgoing edge of the corresponding node.
1.288 + OutEdgeIt& operator++() { return *this; }
1.289 + };
1.290 +
1.291 + /// This iterator goes trough the incoming edges of a node.
1.292 +
1.293 + /// This iterator goes trough the \e incoming edges of a certain node
1.294 + /// of a graph.
1.295 + /// Its usage is quite simple, for example you can count the number
1.296 + /// of outgoing edges of a node \c n
1.297 + /// in graph \c g of type \c Graph as follows.
1.298 + /// \code
1.299 + /// int count=0;
1.300 + /// for(Graph::InEdgeIt e(g, n); e!=INVALID; ++e) ++count;
1.301 + /// \endcode
1.302 +
1.303 + class InEdgeIt : public Edge {
1.304 + public:
1.305 + /// Default constructor
1.306 +
1.307 + /// @warning The default constructor sets the iterator
1.308 + /// to an undefined value.
1.309 + InEdgeIt() { }
1.310 + /// Copy constructor.
1.311 +
1.312 + /// Copy constructor.
1.313 + ///
1.314 + InEdgeIt(const InEdgeIt&) { }
1.315 + /// Initialize the iterator to be invalid.
1.316 +
1.317 + /// Initialize the iterator to be invalid.
1.318 + ///
1.319 + InEdgeIt(Invalid) { }
1.320 + /// This constructor sets the iterator to first incoming edge.
1.321 +
1.322 + /// This constructor set the iterator to the first incoming edge of
1.323 + /// node
1.324 + ///@param n the node
1.325 + ///@param g the graph
1.326 + InEdgeIt(const StaticSymGraph& g, const Node& n) { }
1.327 + /// Edge -> InEdgeIt conversion
1.328 +
1.329 + /// Sets the iterator to the value of the trivial iterator \c e.
1.330 + /// This feature necessitates that each time we
1.331 + /// iterate the edge-set, the iteration order is the same.
1.332 + InEdgeIt(const StaticSymGraph& g, const Edge& n) { }
1.333 + /// Next incoming edge
1.334 +
1.335 + /// Assign the iterator to the next inedge of the corresponding node.
1.336 + ///
1.337 + InEdgeIt& operator++() { return *this; }
1.338 + };
1.339 + /// This iterator goes through each symmetric edge.
1.340 +
1.341 + /// This iterator goes through each symmetric edge of a graph.
1.342 + /// Its usage is quite simple, for example you can count the number
1.343 + /// of symmetric edges in a graph \c g of type \c Graph as follows:
1.344 + /// \code
1.345 + /// int count=0;
1.346 + /// for(Graph::SymEdgeIt e(g); e!=INVALID; ++e) ++count;
1.347 + /// \endcode
1.348 + class SymEdgeIt : public SymEdge {
1.349 + public:
1.350 + /// Default constructor
1.351 +
1.352 + /// @warning The default constructor sets the iterator
1.353 + /// to an undefined value.
1.354 + SymEdgeIt() { }
1.355 + /// Copy constructor.
1.356 +
1.357 + /// Copy constructor.
1.358 + ///
1.359 + SymEdgeIt(const SymEdgeIt&) { }
1.360 + /// Initialize the iterator to be invalid.
1.361 +
1.362 + /// Initialize the iterator to be invalid.
1.363 + ///
1.364 + SymEdgeIt(Invalid) { }
1.365 + /// This constructor sets the iterator to first edge.
1.366 +
1.367 + /// This constructor set the iterator to the first edge of
1.368 + /// node
1.369 + ///@param g the graph
1.370 + SymEdgeIt(const StaticSymGraph& g) { }
1.371 + /// Edge -> EdgeIt conversion
1.372 +
1.373 + /// Sets the iterator to the value of the trivial iterator \c e.
1.374 + /// This feature necessitates that each time we
1.375 + /// iterate the edge-set, the iteration order is the same.
1.376 + SymEdgeIt(const StaticSymGraph&, const SymEdge&) { }
1.377 + ///Next edge
1.378 +
1.379 + /// Assign the iterator to the next
1.380 + /// edge of the corresponding node.
1.381 + SymEdgeIt& operator++() { return *this; }
1.382 + };
1.383 + /// This iterator goes through each edge.
1.384 +
1.385 + /// This iterator goes through each edge of a graph.
1.386 + /// Its usage is quite simple, for example you can count the number
1.387 + /// of edges in a graph \c g of type \c Graph as follows:
1.388 + /// \code
1.389 + /// int count=0;
1.390 + /// for(Graph::EdgeIt e(g); e!=INVALID; ++e) ++count;
1.391 + /// \endcode
1.392 + class EdgeIt : public Edge {
1.393 + public:
1.394 + /// Default constructor
1.395 +
1.396 + /// @warning The default constructor sets the iterator
1.397 + /// to an undefined value.
1.398 + EdgeIt() { }
1.399 + /// Copy constructor.
1.400 +
1.401 + /// Copy constructor.
1.402 + ///
1.403 + EdgeIt(const EdgeIt&) { }
1.404 + /// Initialize the iterator to be invalid.
1.405 +
1.406 + /// Initialize the iterator to be invalid.
1.407 + ///
1.408 + EdgeIt(Invalid) { }
1.409 + /// This constructor sets the iterator to first edge.
1.410 +
1.411 + /// This constructor set the iterator to the first edge of
1.412 + /// node
1.413 + ///@param g the graph
1.414 + EdgeIt(const StaticSymGraph& g) { }
1.415 + /// Edge -> EdgeIt conversion
1.416 +
1.417 + /// Sets the iterator to the value of the trivial iterator \c e.
1.418 + /// This feature necessitates that each time we
1.419 + /// iterate the edge-set, the iteration order is the same.
1.420 + EdgeIt(const StaticSymGraph&, const Edge&) { }
1.421 + ///Next edge
1.422 +
1.423 + /// Assign the iterator to the next
1.424 + /// edge of the corresponding node.
1.425 + EdgeIt& operator++() { return *this; }
1.426 + };
1.427 +
1.428 + /// First node of the graph.
1.429 +
1.430 + /// \retval i the first node.
1.431 + /// \return the first node.
1.432 + ///
1.433 + NodeIt& first(NodeIt& i) const { return i; }
1.434 +
1.435 + /// The first incoming edge.
1.436 +
1.437 + /// The first incoming edge.
1.438 + ///
1.439 + InEdgeIt& first(InEdgeIt &i, Node) const { return i; }
1.440 + /// The first outgoing edge.
1.441 +
1.442 + /// The first outgoing edge.
1.443 + ///
1.444 + OutEdgeIt& first(OutEdgeIt& i, Node) const { return i; }
1.445 + /// The first edge of the Graph.
1.446 +
1.447 + /// The first edge of the Graph.
1.448 + ///
1.449 + EdgeIt& first(EdgeIt& i) const { return i; }
1.450 + /// The first symmetric edge of the Graph.
1.451 +
1.452 + /// The first symmetric edge of the Graph.
1.453 + ///
1.454 + SymEdgeIt& first(SymEdgeIt& i) const { return i; }
1.455 +
1.456 + ///Gives back the head node of an edge.
1.457 +
1.458 + ///Gives back the head node of an edge.
1.459 + ///
1.460 + Node head(Edge) const { return INVALID; }
1.461 + ///Gives back the tail node of an edge.
1.462 +
1.463 + ///Gives back the tail node of an edge.
1.464 + ///
1.465 + Node tail(Edge) const { return INVALID; }
1.466 +
1.467 + ///Gives back the first node of an symmetric edge.
1.468 +
1.469 + ///Gives back the first node of an symmetric edge.
1.470 + ///
1.471 + Node head(SymEdge) const { return INVALID; }
1.472 + ///Gives back the second node of an symmetric edge.
1.473 +
1.474 + ///Gives back the second node of an symmetric edge.
1.475 + ///
1.476 + Node tail(SymEdge) const { return INVALID; }
1.477 + ///Gives back the \e id of a node.
1.478 +
1.479 + ///\warning Not all graph structures provide this feature.
1.480 + ///
1.481 + ///\todo Should each graph provide \c id?
1.482 + int id(const Node&) const { return 0; }
1.483 + ///Gives back the \e id of an edge.
1.484 +
1.485 + ///\warning Not all graph structures provide this feature.
1.486 + ///
1.487 + ///\todo Should each graph provide \c id?
1.488 + int id(const Edge&) const { return 0; }
1.489 +
1.490 + ///\warning Not all graph structures provide this feature.
1.491 + ///
1.492 + ///\todo Should each graph provide \c id?
1.493 + int id(const SymEdge&) const { return 0; }
1.494 +
1.495 + ///\e
1.496 +
1.497 + ///\todo Should it be in the concept?
1.498 + ///
1.499 + int nodeNum() const { return 0; }
1.500 + ///\e
1.501 +
1.502 + ///\todo Should it be in the concept?
1.503 + ///
1.504 + int edgeNum() const { return 0; }
1.505 +
1.506 + ///\todo Should it be in the concept?
1.507 + ///
1.508 + int symEdgeNum() const { return 0; }
1.509 +
1.510 +
1.511 + /// Gives back the forward directed edge of the symmetric edge.
1.512 + Edge forward(SymEdge) const {return INVALID;}
1.513 +
1.514 + /// Gives back the backward directed edge of the symmetric edge.
1.515 + Edge backward(SymEdge) const {return INVALID;};
1.516 +
1.517 + /// Gives back the opposite of the edge.
1.518 + Edge opposite(Edge) const {return INVALID;}
1.519 +
1.520 + ///Reference map of the nodes to type \c T.
1.521 + /// \ingroup concept
1.522 + ///Reference map of the nodes to type \c T.
1.523 + /// \sa Reference
1.524 + /// \warning Making maps that can handle bool type (NodeMap<bool>)
1.525 + /// needs some extra attention!
1.526 + template<class T> class NodeMap : public ReferenceMap< Node, T >
1.527 + {
1.528 + public:
1.529 +
1.530 + ///\e
1.531 + NodeMap(const StaticSymGraph&) { }
1.532 + ///\e
1.533 + NodeMap(const StaticSymGraph&, T) { }
1.534 +
1.535 + ///Copy constructor
1.536 + template<typename TT> NodeMap(const NodeMap<TT>&) { }
1.537 + ///Assignment operator
1.538 + template<typename TT> NodeMap& operator=(const NodeMap<TT>&)
1.539 + { return *this; }
1.540 + };
1.541 +
1.542 + ///Reference map of the edges to type \c T.
1.543 +
1.544 + /// \ingroup concept
1.545 + ///Reference map of the edges to type \c T.
1.546 + /// \sa Reference
1.547 + /// \warning Making maps that can handle bool type (EdgeMap<bool>)
1.548 + /// needs some extra attention!
1.549 + template<class T> class EdgeMap
1.550 + : public ReferenceMap<Edge,T>
1.551 + {
1.552 + public:
1.553 +
1.554 + ///\e
1.555 + EdgeMap(const StaticSymGraph&) { }
1.556 + ///\e
1.557 + EdgeMap(const StaticSymGraph&, T) { }
1.558 +
1.559 + ///Copy constructor
1.560 + template<typename TT> EdgeMap(const EdgeMap<TT>&) { }
1.561 + ///Assignment operator
1.562 + template<typename TT> EdgeMap &operator=(const EdgeMap<TT>&)
1.563 + { return *this; }
1.564 + };
1.565 +
1.566 + ///Reference map of the edges to type \c T.
1.567 +
1.568 + /// \ingroup concept
1.569 + ///Reference map of the symmetric edges to type \c T.
1.570 + /// \sa Reference
1.571 + /// \warning Making maps that can handle bool type (EdgeMap<bool>)
1.572 + /// needs some extra attention!
1.573 + template<class T> class SymEdgeMap
1.574 + : public ReferenceMap<SymEdge,T>
1.575 + {
1.576 + public:
1.577 +
1.578 + ///\e
1.579 + SymEdgeMap(const StaticSymGraph&) { }
1.580 + ///\e
1.581 + SymEdgeMap(const StaticSymGraph&, T) { }
1.582 +
1.583 + ///Copy constructor
1.584 + template<typename TT> SymEdgeMap(const SymEdgeMap<TT>&) { }
1.585 + ///Assignment operator
1.586 + template<typename TT> SymEdgeMap &operator=(const SymEdgeMap<TT>&)
1.587 + { return *this; }
1.588 + };
1.589 + };
1.590 +
1.591 +
1.592 +
1.593 + /// An empty non-static graph class.
1.594 +
1.595 + /// This class provides everything that \ref StaticGraph
1.596 + /// with additional functionality which enables to build a
1.597 + /// graph from scratch.
1.598 + class ExtendableSymGraph : public StaticSymGraph
1.599 + {
1.600 + public:
1.601 + /// Defalult constructor.
1.602 +
1.603 + /// Defalult constructor.
1.604 + ///
1.605 + ExtendableSymGraph() { }
1.606 + ///Add a new node to the graph.
1.607 +
1.608 + /// \return the new node.
1.609 + ///
1.610 + Node addNode() { return INVALID; }
1.611 + ///Add a new edge to the graph.
1.612 +
1.613 + ///Add a new symmetric edge to the graph with tail node \c t
1.614 + ///and head node \c h.
1.615 + ///\return the new edge.
1.616 + SymEdge addEdge(Node h, Node t) { return INVALID; }
1.617 +
1.618 + /// Resets the graph.
1.619 +
1.620 + /// This function deletes all edges and nodes of the graph.
1.621 + /// It also frees the memory allocated to store them.
1.622 + /// \todo It might belong to \ref ErasableGraph.
1.623 + void clear() { }
1.624 + };
1.625 +
1.626 + /// An empty erasable graph class.
1.627 +
1.628 + /// This class is an extension of \ref ExtendableGraph. It also makes it
1.629 + /// possible to erase edges or nodes.
1.630 + class ErasableSymGraph : public ExtendableSymGraph
1.631 + {
1.632 + public:
1.633 + /// Defalult constructor.
1.634 +
1.635 + /// Defalult constructor.
1.636 + ///
1.637 + ErasableSymGraph() { }
1.638 + /// Deletes a node.
1.639 +
1.640 + /// Deletes node \c n node.
1.641 + ///
1.642 + void erase(Node n) { }
1.643 + /// Deletes an edge.
1.644 +
1.645 + /// Deletes edge \c e edge.
1.646 + ///
1.647 + void erase(SymEdge e) { }
1.648 + };
1.649 +
1.650 + // @}
1.651 + } //namespace concept
1.652 +} //namespace lemon
1.653 +
1.654 +
1.655 +
1.656 +#endif // LEMON_CONCEPT_GRAPH_H