\( \newcommand{\E}{\mathrm{E}} \) \( \newcommand{\A}{\mathrm{A}} \) \( \newcommand{\R}{\mathrm{R}} \) \( \newcommand{\N}{\mathrm{N}} \) \( \newcommand{\Q}{\mathrm{Q}} \) \( \newcommand{\Z}{\mathrm{Z}} \) \( \def\ccSum #1#2#3{ \sum_{#1}^{#2}{#3} } \def\ccProd #1#2#3{ \sum_{#1}^{#2}{#3} }\)

CGAL 4.8 - Profiling tools, Hash Map, Union-find, Modifiers

All Classes Namespaces Files Functions Variables Typedefs Enumerations Enumerator Groups Pages
List of all members
CGAL::Modifier_base< R > Class Template Reference
Profiling Tools, Hash Map, Union-find, Modifiers Reference

`#include <CGAL/Modifier_base.h>`

## Definition

`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.

Example

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
public:
void delegate( CGAL::Modifier_base<int>& modifier) {
modifier(i);
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.
}

## Types
typedef R | Representation
| the internal representation type.

## Operations
virtual void | operator() (R &rep)

## Member Function Documentation

template<typename R>

virtual void CGAL::Modifier_base< R >::operator() | ( | R & | rep) |  |
| virtual

Postcondition
  `rep` is a valid representation.