CGAL 5.2 - Profiling tools, Hash Map, Union-find, Modifiers
CGAL::Modifier_base< R > Class Template Reference

#include <CGAL/Modifier_base.h>


Modifier_base is an abstract base class providing the interface for any modifier.

A modifier is a function object derived from Modifier_base that implements the pure virtual member function operator(), which accepts a single reference parameter R& on which the modifier is allowed to work. R is the type of the internal representation that is to be modified.


The following fragment defines a class A with an internal representation i of type int. It provides a member function delegate(), which gives a modifier access to the internal variable and checks validity thereafter. The example modifier sets the internal variable to 42. The example function applies the modifier to an instance of class A.

class A {
int i; // protected internal representation
void delegate( CGAL::Modifier_base<int>& modifier) {
CGAL_postcondition( i > 0); // check validity
struct Modifier : public CGAL::Modifier_base<int> {
void operator()( int& rep) { rep = 42;}
void use_it() {
A a;
Modifier m;
a.delegate(m); // a.i == 42 and A has checked that A::i > 0.


typedef R Representation
 the internal representation type.


virtual void operator() (R &rep)

Member Function Documentation

◆ operator()()

template<typename R>
virtual void CGAL::Modifier_base< R >::operator() ( R &  rep)
rep is a valid representation.