Version 5.0 The LEDA User Manual

13.14 Constant Accessors ( constant da )
1. Definition
An instance ca of class constant da is bound to a specific value of type T, and the
function get(ca, it) simply returns this value for each iterator.
#include < LEDA/graph/graph iterator.h >
2. Creation
constant da ca(T t);
introduces a variable ca of this class bound to the given value t.
3. Operations
T
get(const constant da& ca, const Iter& it)
returns the value to which ca is bound.
4. Example
With the template function of sect. 13.13 we can write a function that counts the number
of nodes in a graph:
int count_all(graph G) {
constant_da Color(red);
return count_red_t(G,Color); }
13.15 Node Member Accessors ( node member da )
1. Definition
An instance da of class node member da manages the access to a node parameter
that is organized as a member of a struct type, which is the first template argument of a
parameterized graph GRAPH. The parameter is of type T and the struct of type
Str.
Classes edge member da is defined completely analogously.
#include < LEDA/graph/graph iterator.h >