CGAL::Circulator_from_iterator< I > Class Template Reference

#include <CGAL/circulator.h>

Definition

The adaptor Circulator_from_iterator converts two iterators of type I, a begin and a past-the-end value, to a circulator of equal category.

The iterator must be at least of the forward iterator category. The circulator will be mutable or non-mutable according to the iterator. Iterators provide no size_type. This adapter assumes std::size_t instead.

Operations

The adaptor conforms to the requirements of the respective circulator category. An additional member function current_iterator() returns the current iterator pointing to the same position as the circulator does.

See Also

Container_from_circulator

Circulator_from_container

Circulator

Example

The following program composes two adaptors - from an iterator to a circulator and back to an iterator. It applies an STL sort algorithm on a STL vector containing three elements. The resulting vector will be [2 5 9] as it is checked by the assertions. The program is part of the CGAL distribution.

File Circulator/circulator_prog1.cpp

#include <CGAL/basic.h>
#include <cassert>
#include <vector>
#include <algorithm>
#include <CGAL/circulator.h>

typedef  std::vector<int>::iterator                  I;
typedef  CGAL::Circulator_from_iterator<I>           Circulator;
typedef  CGAL::Container_from_circulator<Circulator> Container;
typedef  Container::iterator                         Iterator;

int main() {
    std::vector<int> v;
    v.push_back(5);
    v.push_back(2);
    v.push_back(9);
    Circulator c( v.begin(), v.end());
    Container  container( c);
    std::sort( container.begin(), container.end());
    Iterator i = container.begin();
    assert( *i == 2);
    i++;    assert( *i == 5);
    i++;    assert( *i == 9);
    i++;    assert(  i == container.end());
    return 0;
}

Another example usage for this adaptor is a random access circulator over the built-in C arrays. Given an array of type T* with a begin pointer b and a past-the-end pointer e the adaptor Circulator_from_iterator<T*> c(b,e) is a random access circulator c over this array.

Examples:

Circulator/circulator_prog1.cpp.

Types
In addition all types required for circulators are provided.
typedef I	iterator

Creation
	Circulator_from_iterator ()
	a circulator c on an empty sequence.
	Circulator_from_iterator (const I &begin, const I &end, const I &cur=begin)
	a circulator c initialized to refer to the element *cur in a range [begin, end). More...
	Circulator_from_iterator (const Circulator_from_iterator< I, T, Size, Dist > &d, const I &cur)
	a copy of circulator d referring to the element *cur. More...

Constructor & Destructor Documentation

template<typename I>

CGAL::Circulator_from_iterator< I >::Circulator_from_iterator	(	const I &	begin,
		const I &	end,
		const I &	cur = begin
	)

a circulator c initialized to refer to the element *cur in a range [begin, end).

The circulator c refers to a empty sequence if begin==end.

template<typename I>

CGAL::Circulator_from_iterator< I >::Circulator_from_iterator	(	const Circulator_from_iterator< I, T, Size, Dist > &	d,
		const I &	cur
	)

a copy of circulator d referring to the element *cur.

The circulator c refers to a empty sequence if d does so.