CGAL::Inverse_index< IC > Class Template Reference

#include <CGAL/iterator.h>

Definition

template<typename IC>
class CGAL::Inverse_index< IC >

The class Inverse_index constructs an inverse index for a given range [i,j) of two iterators or circulators of type IC.

The first element I in the range [i,j) has the index 0. Consecutive elements are numbered incrementally. The inverse index provides a query for a given iterator or circulator k to retrieve its index number.

Precondition

The iterator or circulator must be either of the random access category or the dereference operator must return stable and distinguishable addresses for the values, e.g. proxies or non-modifiable iterator with opaque values will not work.

Implementation

For random access iterators or circulators, it is done in constant time by subtracting i. For other iterator categories, an STL map is used, which results in a log(j-i) query time. The comparisons are done using the operator operator< on pointers.

See also

CGAL::Random_access_adaptor<IC>

CGAL::Random_access_value_adaptor<IC,T>

Creation
	Inverse_index ()
	invalid index.
	Inverse_index (const IC &i)
	empty inverse index initialized to start at i.
	Inverse_index (const IC &i, const IC &j)
	inverse index initialized with range [i,j).

Operations
std::size_t	operator[] (const IC &k)
	returns inverse index of k.
void	push_back (const IC &k)
	adds k at the end of the indices.

Member Function Documentation

operator[]()

template<typename IC >

std::size_t CGAL::Inverse_index< IC >::operator[]

(

const IC &

k

)

returns inverse index of k.

Precondition

k has been stored in the inverse index.