ListDigraph::Snapshot Class Reference

Detailed Description

Class to make a snapshot of the digraph and restore it later.

The newly added nodes and arcs can be removed using the restore() function.

Note

After a state is restored, you cannot restore a later state, i.e. you cannot add the removed nodes and arcs again using another Snapshot instance.

Warning

Node and arc deletions and other modifications (e.g. reversing, contracting, splitting arcs or nodes) cannot be restored. These events invalidate the snapshot. However, the arcs and nodes that were added to the digraph after making the current snapshot can be removed without invalidating it.

#include <lemon/list_graph.h>

Public Member Functions
	Snapshot ()
	Default constructor. More...
	Snapshot (ListDigraph &gr)
	Constructor that immediately makes a snapshot. More...
void	save (ListDigraph &gr)
	Make a snapshot. More...
void	restore ()
	Undo the changes until the last snapshot. More...
bool	valid () const
	Returns true if the snapshot is valid. More...

Constructor & Destructor Documentation

Snapshot ( )

inline

Default constructor. You have to call save() to actually make a snapshot.

Snapshot ( ListDigraph &  gr )

inline

This constructor immediately makes a snapshot of the given digraph.

Member Function Documentation

void save ( ListDigraph &  gr )

inline

This function makes a snapshot of the given digraph. It can be called more than once. In case of a repeated call, the previous snapshot gets lost.

void restore ( )

inline

This function undos the changes until the last snapshot created by save() or Snapshot(ListDigraph&).

Warning

This method invalidates the snapshot, i.e. repeated restoring is not supported unless you call save() again.

bool valid ( ) const

inline

This function returns true if the snapshot is valid.