cgal/Packages/STL_Extension/include/CGAL/iterator.h

1055 lines
31 KiB
C++

// ============================================================================
//
// Copyright (c) 2003 The CGAL Consortium
//
// This software and related documentation is part of an INTERNAL release
// of the Computational Geometry Algorithms Library (CGAL). It is not
// intended for general use.
//
// ----------------------------------------------------------------------------
//
// release : $CGAL_Revision: $
// release_date : $CGAL_Date: $
//
// file : iterator.h
// chapter : $CGAL_Chapter: STL Extensions for CGAL $
// package : $CGAL_Package: STL_Extension $
// source : stl_extension.fw
// revision : $Revision$
// revision_date : $Date$
// author(s) : Michael Hoffmann <hoffmann@inf.ethz.ch>
// Lutz Kettner <kettner@mpi-sb.mpg.de>
// Sylvain Pion <Sylvain.Pion@mpi-sb.mpg.de>
//
// maintainer : Michael Hoffmann <hoffmann@inf.ethz.ch>
// coordinator : ETH
//
// Iterators and Iterator Adaptors
// ============================================================================
#ifndef CGAL_ITERATOR_H
#define CGAL_ITERATOR_H 1
#include <CGAL/circulator.h>
#include <vector>
#include <map>
CGAL_BEGIN_NAMESPACE
// +----------------------------------------------------------------+
// | Emptyset_iterator
// +----------------------------------------------------------------+
// | sends everything to /dev/null
// +----------------------------------------------------------------+
struct Emptyset_iterator
#if defined(__GNUC__) && (__GNUC__ < 3)
: public std::output_iterator
#else
: public std::iterator< std::output_iterator_tag, void, void, void*, void >
#endif // defined(__GNUC__) && (__GNUC__ < 3)
{
Emptyset_iterator() {}
Emptyset_iterator(const Emptyset_iterator&) {}
template< class T >
Emptyset_iterator& operator=(const T&) { return *this; }
Emptyset_iterator& operator++() { return *this; }
Emptyset_iterator& operator++(int) { return *this; }
Emptyset_iterator& operator*() { return *this; }
};
// +---------------------------------------------------------------------+
// | Insert_iterator
// +---------------------------------------------------------------------+
// | Insert output iterator, which calls insert(value) on the container.
// | Similar to std::insert_iterator<> except it doesn't pass an iterator.
// +---------------------------------------------------------------------+
template < class Container >
class Insert_iterator
#if defined(__GNUC__) && (__GNUC__ < 3)
: public std::output_iterator
#else
: public std::iterator< std::output_iterator_tag, void, void, void*, void >
#endif // defined(__GNUC__) && (__GNUC__ < 3)
{
protected:
Container *container;
public:
typedef Container container_type;
explicit Insert_iterator(Container &c)
: container(&c) {}
Insert_iterator&
operator=(typename Container::const_reference value)
{
container->insert(value);
return *this;
}
Insert_iterator&
operator*() { return *this; }
Insert_iterator&
operator++() { return *this; }
Insert_iterator
operator++(int) { return *this; }
};
template < class Container >
inline Insert_iterator<Container>
inserter(Container &x)
{ return Insert_iterator<Container>(x); }
// +----------------------------------------------------------------+
// | Oneset_iterator
// +----------------------------------------------------------------+
// | stores a reference to an object of type T
// | which will be affected by operator*().
// +----------------------------------------------------------------+
template < class T >
class Oneset_iterator
#if defined(__GNUC__) && (__GNUC__ < 3)
: public std::output_iterator
#else
: public std::iterator< std::output_iterator_tag, void, void, void*, void >
#endif // defined(__GNUC__) && (__GNUC__ < 3)
{
T& t;
public:
Oneset_iterator(T& tt) : t(tt) {}
Oneset_iterator& operator++() { return *this; }
Oneset_iterator& operator++(int) { return *this; }
T& operator*() { return t; }
};
template < class I,
class Val = typename std::iterator_traits<I>::value_type >
class Counting_iterator {
protected:
I nt; // The internal iterator.
std::size_t d_i; // The internal counter.
public:
typedef I Iterator;
typedef Counting_iterator<I,Val> Self;
typedef std::input_iterator_tag iterator_category;
typedef Val value_type;
typedef std::ptrdiff_t difference_type;
typedef const value_type& reference;
typedef const value_type* pointer;
// CREATION
// --------
Counting_iterator( std::size_t i = 0) : d_i(i) {}
Counting_iterator( Iterator j, std::size_t i = 0) : nt(j), d_i(i) {}
// OPERATIONS Forward Category
// ---------------------------
Iterator current_iterator() const { return nt;}
std::size_t current_counter() const { return d_i;}
bool operator==( const Self& i) const { return ( d_i == i.d_i); }
bool operator!=( const Self& i) const { return !(*this == i); }
reference operator*() const { return *nt; }
pointer operator->() const { return nt.operator->(); }
Self& operator++() {
++nt;
++d_i;
return *this;
}
Self operator++(int) {
Self tmp = *this;
++*this;
return tmp;
}
};
template < class I, int N,
class Ref = typename std::iterator_traits<I>::reference,
class Ptr = typename std::iterator_traits<I>::pointer,
class Val = typename std::iterator_traits<I>::value_type,
class Dist = typename std::iterator_traits<I>::difference_type,
class Ctg = typename std::iterator_traits<I>::iterator_category >
class N_step_adaptor {
protected:
I nt; // The internal iterator.
public:
typedef I Iterator;
typedef N_step_adaptor<I,N> Self;
typedef std::iterator_traits<I> ITI;
typedef typename ITI::reference reference;
typedef typename ITI::pointer pointer;
typedef typename ITI::value_type value_type;
typedef typename ITI::difference_type difference_type;
typedef typename ITI::iterator_category iterator_category;
// Special for circulators.
typedef I_Circulator_size_traits<iterator_category,I> C_S_Traits;
typedef typename C_S_Traits::size_type size_type;
// CREATION
// --------
N_step_adaptor() {}
N_step_adaptor( Iterator j) : nt(j) {}
template <class II>
N_step_adaptor( const N_step_adaptor<II,N>& j)
: nt( j.current_iterator()) {}
// OPERATIONS Forward Category
// ---------------------------
// Circulator stuff.
typedef I Circulator;
Circulator current_circulator() const { return nt;}
Iterator current_iterator() const { return nt;}
bool operator==( CGAL_NULL_TYPE p) const {
CGAL_assertion( p == 0);
return ( nt == 0);
}
bool operator!=( CGAL_NULL_TYPE p) const { return !(*this == p); }
bool operator==( const Self& i) const { return ( nt == i.nt); }
bool operator!=( const Self& i) const { return !(*this == i); }
reference operator*() const { return *nt; }
pointer operator->() const { return nt.operator->(); }
Self& operator++() {
std::advance( nt, N);
return *this;
}
Self operator++(int) {
Self tmp = *this;
++*this;
return tmp;
}
// OPERATIONS Bidirectional Category
// ---------------------------------
Self& operator--() {
std::advance( nt, -N);
return *this;
}
Self operator--(int) {
Self tmp = *this;
--*this;
return tmp;
}
// OPERATIONS Random Access Category
// ---------------------------------
Self min_circulator() const { return Self( nt.min_circulator()); }
Self& operator+=( difference_type n) {
nt += difference_type(N * n);
return *this;
}
Self operator+( difference_type n) const {
Self tmp = *this;
tmp.nt += difference_type(N * n);
return tmp;
}
Self& operator-=( difference_type n) {
return operator+=( -n);
}
Self operator-( difference_type n) const {
Self tmp = *this;
return tmp += -n;
}
difference_type operator-( const Self& i) const { return (nt-i.nt)/N;}
reference operator[]( difference_type n) const {
Self tmp = *this;
tmp += n;
return tmp.operator*();
}
bool operator<( const Self& i) const { return ( nt < i.nt); }
bool operator>( const Self& i) const { return i < *this; }
bool operator<=( const Self& i) const { return !(i < *this); }
bool operator>=( const Self& i) const { return !(*this < i); }
};
template < class I, int N > inline
N_step_adaptor<I,N>
operator+( typename N_step_adaptor<I,N>::difference_type n,
N_step_adaptor<I,N> i)
{ return i += n; }
template < class I, int N>
class N_step_adaptor_derived : public I {
public:
typedef I Iterator;
typedef I Circulator;
typedef N_step_adaptor_derived<I,N> Self;
typedef typename I::iterator_category iterator_category;
typedef typename I::value_type value_type;
typedef typename I::difference_type difference_type;
typedef typename I::reference reference;
typedef typename I::pointer pointer;
// Special for circulators.
typedef I_Circulator_size_traits<iterator_category,I> C_S_Traits;
typedef typename C_S_Traits::size_type size_type;
// CREATION
// --------
N_step_adaptor_derived() {}
N_step_adaptor_derived( Iterator j) : I(j) {}
template <class II>
N_step_adaptor_derived( const N_step_adaptor_derived<II,N>& j)
: I( j.current_iterator()) {}
// OPERATIONS Forward Category
// ---------------------------
Circulator current_circulator() const { return *this;}
Iterator current_iterator() const { return *this;}
Self& operator++() {
std::advance( (I&)*this, N);
return *this;
}
Self operator++(int) {
Self tmp = *this;
++*this;
return tmp;
}
// OPERATIONS Bidirectional Category
// ---------------------------------
Self& operator--() {
std::advance( (I&)*this, -N);
return *this;
}
Self operator--(int) {
Self tmp = *this;
--*this;
return tmp;
}
// OPERATIONS Random Access Category
// ---------------------------------
Self min_circulator() const { return Self( I::min_circulator()); }
Self& operator+=( difference_type n) {
I::operator+=( difference_type(N * n));
return *this;
}
Self operator+( difference_type n) const {
Self tmp = *this;
tmp += n;
return tmp;
}
Self& operator-=( difference_type n) {
return operator+=( -n);
}
Self operator-( difference_type n) const {
Self tmp = *this;
return tmp += -n;
}
difference_type operator-( const Self& i) const {
return (I::operator-(i)) / N;
}
reference operator[]( difference_type n) const {
Self tmp = *this;
tmp += n;
return tmp.operator*();
}
};
template < class I, int N>
inline
N_step_adaptor_derived<I,N>
operator+( typename N_step_adaptor_derived<I,N>::difference_type n,
N_step_adaptor_derived<I,N> i)
{ return i += n; }
template < class I, class P > struct Filter_iterator;
template < class I, class P >
bool operator==(const Filter_iterator<I,P>&, const Filter_iterator<I,P>&);
template < class I, class P >
struct Filter_iterator {
typedef I Iterator;
typedef P Predicate;
typedef Filter_iterator<I,P> Self;
typedef std::iterator_traits<I> ITI;
typedef typename ITI::reference reference;
typedef typename ITI::pointer pointer;
typedef typename ITI::value_type value_type;
typedef typename ITI::difference_type difference_type;
typedef typename ITI::iterator_category iterator_category;
// Special for circulators.
typedef I_Circulator_size_traits<iterator_category,I> C_S_Traits;
typedef typename C_S_Traits::size_type size_type;
protected:
Iterator b_, e_; // The range.
Iterator c_; // current position.
Predicate p_; // Leave out x <==> p_(x).
public:
Filter_iterator() {}
Filter_iterator(Iterator b, Iterator e, const Predicate& p)
: b_(b), e_(e), c_(b), p_(p)
{
while (c_ != e_ && p_(c_))
++c_;
}
Filter_iterator(Iterator b, Iterator e, const Predicate& p, Iterator c)
: b_(b), e_(e), c_(c), p_(p)
{
while (c_ != e_ && p_(c_))
++c_;
}
Self& operator++() {
do { ++c_; } while (c_ != e_ && p_(c_));
return *this;
}
Self& operator--() {
if (c_ != b_)
do {
--c_;
} while (c_ != b_ && p_(c_));
return *this;
}
Self operator++(int) {
Self tmp(*this);
++(*this);
return tmp;
}
Self operator--(int) {
Self tmp(*this);
--(*this);
return tmp;
}
reference operator*() const { return *c_; }
pointer operator->() const { return &*c_; }
const Predicate& predicate() const { return p_; }
Iterator base() const { return c_; }
bool is_end() const { return (c_ == e_); }
friend bool operator== <>(const Self&, const Self&);
};
template < class I, class P >
inline Filter_iterator< I, P >
filter_iterator(I b, I e, const P& p)
{ return Filter_iterator< I, P >(b, e, p); }
template < class I, class P >
inline Filter_iterator< I, P >
filter_iterator(I b, I e, const P& p, I c)
{ return Filter_iterator< I, P >(b, e, p, c); }
template < class I, class P >
bool operator==(const Filter_iterator<I,P>& it1,
const Filter_iterator<I,P>& it2)
{
CGAL_precondition(it1.b_ == it2.b_ && it1.e_ == it2.e_);
return it1.base() == it2.base();
}
template < class I, class P >
bool operator!=(const Filter_iterator<I,P>& it1,
const Filter_iterator<I,P>& it2)
{ return !(it1 == it2); }
template < class I1, class Creator >
class Join_input_iterator_1 {
// the join of one iterator `i1'. Applies `Creator' with
// one argument `*i1'. `value_type' is equal to
// `Creator::result_type'.
public:
typedef Join_input_iterator_1<I1,Creator> Self;
typedef std::input_iterator_tag iterator_category;
typedef typename Creator::result_type value_type;
typedef std::iterator_traits<I1> ITraits;
typedef typename ITraits::difference_type difference_type;
typedef const value_type& reference;
typedef const value_type* pointer;
protected:
I1 j1; // The 1st internal iterator.
value_type val; // The current (internal) value.
public:
// CREATION
// --------
Join_input_iterator_1() {}
Join_input_iterator_1( I1 i1) : j1(i1), val(Creator()(*j1)) {}
// OPERATIONS Forward Category
// ---------------------------
I1 current_iterator1() const { return j1;}
bool operator==( const Self& i) const { return ( j1 == i.j1); }
bool operator!=( const Self& i) const { return !(*this == i); }
reference operator*() const { return val; }
pointer operator->() const { return &val; }
Self& operator++() {
++j1;
val = Creator()(*j1);
return *this;
}
Self operator++(int) {
Self tmp = *this;
++*this;
return tmp;
}
};
template < class I1, class I2, class Creator >
class Join_input_iterator_2 {
// the join of two iterators `i1' and `i2'. Applies `Creator' with
// two arguments `*i1' and `*i2'. `value_type' is equal to
// `Creator::result_type'.
public:
typedef Join_input_iterator_2<I1,I2,Creator> Self;
typedef std::input_iterator_tag iterator_category;
typedef typename Creator::result_type value_type;
typedef std::iterator_traits<I1> ITraits;
typedef typename ITraits::difference_type difference_type;
typedef const value_type& reference;
typedef const value_type* pointer;
protected:
I1 j1; // The 1st internal iterator.
I2 j2; // The 2nd internal iterator.
value_type val; // The current (internal) value.
public:
// CREATION
// --------
Join_input_iterator_2() {}
Join_input_iterator_2( I1 i1, I2 i2)
: j1(i1), j2(i2), val(Creator()(*j1,*j2)) {}
// OPERATIONS Forward Category
// ---------------------------
I1 current_iterator1() const { return j1;}
I2 current_iterator2() const { return j2;}
bool operator==( const Self& i) const {
return ( j1 == i.j1 && j2 == i.j2);
}
bool operator!=( const Self& i) const { return !(*this == i); }
reference operator*() const { return val; }
pointer operator->() const { return &val; }
Self& operator++() {
++j1;
++j2;
val = Creator()(*j1,*j2);
return *this;
}
Self operator++(int) {
Self tmp = *this;
++*this;
return tmp;
}
};
template < class I1, class I2, class I3, class Creator >
class Join_input_iterator_3 {
// the join of two iterators `i1' up to `i3'. Applies `Creator' with
// three arguments `*i1' up to `*i3'. `value_type' is equal to
// `Creator::result_type'.
public:
typedef Join_input_iterator_3<I1,I2,I3,Creator> Self;
typedef std::input_iterator_tag iterator_category;
typedef typename Creator::result_type value_type;
typedef std::iterator_traits<I1> ITraits;
typedef typename ITraits::difference_type difference_type;
typedef const value_type& reference;
typedef const value_type* pointer;
protected:
I1 j1; // The 1st internal iterator.
I2 j2; // The 2nd internal iterator.
I3 j3; // The 3rd internal iterator.
value_type val; // The current (internal) value.
public:
// CREATION
// --------
Join_input_iterator_3() {}
Join_input_iterator_3( I1 i1, I2 i2, I3 i3)
: j1(i1), j2(i2), j3(i3), val(Creator()(*j1,*j2,*j3)) {}
// OPERATIONS Forward Category
// ---------------------------
I1 current_iterator1() const { return j1;}
I2 current_iterator2() const { return j2;}
I3 current_iterator3() const { return j3;}
bool operator==( const Self& i) const {
return ( j1 == i.j1 && j2 == i.j2 && j3 == i.j3);
}
bool operator!=( const Self& i) const { return !(*this == i); }
reference operator*() const { return val; }
pointer operator->() const { return &val; }
Self& operator++() {
++j1;
++j2;
++j3;
val = Creator()(*j1,*j2,*j3);
return *this;
}
Self operator++(int) {
Self tmp = *this;
++*this;
return tmp;
}
};
template < class I1, class I2, class I3, class I4, class Creator >
class Join_input_iterator_4 {
// the join of two iterators `i1' up to `i4'. Applies `Creator' with
// four arguments `*i1' up to `*i4'. `value_type' is equal to
// `Creator::result_type'.
public:
typedef Join_input_iterator_4<I1,I2,I3,I4,Creator> Self;
typedef std::input_iterator_tag iterator_category;
typedef typename Creator::result_type value_type;
typedef std::iterator_traits<I1> ITraits;
typedef typename ITraits::difference_type difference_type;
typedef const value_type& reference;
typedef const value_type* pointer;
protected:
I1 j1; // The 1st internal iterator.
I2 j2; // The 2nd internal iterator.
I3 j3; // The 3rd internal iterator.
I4 j4; // The 4th internal iterator.
value_type val; // The current (internal) value.
public:
// CREATION
// --------
Join_input_iterator_4() {}
Join_input_iterator_4( I1 i1, I2 i2, I3 i3, I4 i4)
: j1(i1), j2(i2), j3(i3), j4(i4), val(Creator()(*j1,*j2,*j3,*j4)){}
// OPERATIONS Forward Category
// ---------------------------
I1 current_iterator1() const { return j1;}
I2 current_iterator2() const { return j2;}
I3 current_iterator3() const { return j3;}
I4 current_iterator4() const { return j4;}
bool operator==( const Self& i) const {
return ( j1 == i.j1 &&
j2 == i.j2 &&
j3 == i.j3 &&
j4 == i.j4);
}
bool operator!=( const Self& i) const { return !(*this == i); }
reference operator*() const { return val; }
pointer operator->() const { return &val; }
Self& operator++() {
++j1;
++j2;
++j3;
++j4;
val = Creator()(*j1,*j2,*j3,*j4);
return *this;
}
Self operator++(int) {
Self tmp = *this;
++*this;
return tmp;
}
};
template < class I1, class I2, class I3, class I4, class I5,
class Creator >
class Join_input_iterator_5 {
// the join of two iterators `i1' up to `i5'. Applies `Creator' with
// five arguments `*i1' up to `*i5'. `value_type' is equal to
// `Creator::result_type'.
public:
typedef Join_input_iterator_5<I1,I2,I3,I4,I5,Creator> Self;
typedef std::input_iterator_tag iterator_category;
typedef typename Creator::result_type value_type;
typedef std::iterator_traits<I1> ITraits;
typedef typename ITraits::difference_type difference_type;
typedef const value_type& reference;
typedef const value_type* pointer;
protected:
I1 j1; // The 1st internal iterator.
I2 j2; // The 2nd internal iterator.
I3 j3; // The 3rd internal iterator.
I4 j4; // The 4th internal iterator.
I5 j5; // The 5th internal iterator.
value_type val; // The current (internal) value.
public:
// CREATION
// --------
Join_input_iterator_5() {}
Join_input_iterator_5( I1 i1, I2 i2, I3 i3, I4 i4, I5 i5)
: j1(i1), j2(i2), j3(i3), j4(i4), j5(i5),
val(Creator()(*j1,*j2,*j3,*j4,*j5)) {}
// OPERATIONS Forward Category
// ---------------------------
I1 current_iterator1() const { return j1;}
I2 current_iterator2() const { return j2;}
I3 current_iterator3() const { return j3;}
I4 current_iterator4() const { return j4;}
I5 current_iterator5() const { return j5;}
bool operator==( const Self& i) const {
return ( j1 == i.j1 &&
j2 == i.j2 &&
j3 == i.j3 &&
j4 == i.j4 &&
j5 == i.j5);
}
bool operator!=( const Self& i) const { return !(*this == i); }
reference operator*() const { return val; }
pointer operator->() const { return &val; }
Self& operator++() {
++j1;
++j2;
++j3;
++j4;
++j5;
val = Creator()(*j1,*j2,*j3,*j4,*j5);
return *this;
}
Self operator++(int) {
Self tmp = *this;
++*this;
return tmp;
}
};
template < class IC>
class Inverse_index {
// DEFINITION
//
// The class Inverse_index<IC,T> constructs an inverse index for a
// given range [i,j) of two iterators or circulators of type `IC' with the
// value type `T'. 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. 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. A comparison operator `operator<' is needed for
// `T*'.
//
// CREATION
protected:
typedef std::map< const void*, std::size_t, std::less<const void*> >
Index;
Index idx;
IC start;
typedef typename Index::iterator Index_iterator;
typedef typename Index::const_iterator Index_const_iterator;
typedef typename Index::value_type Item;
protected:
void ini_idx( IC i, const IC& j, std::input_iterator_tag);
void ini_idx( const IC& i, const IC& j, std::forward_iterator_tag){
ini_idx( i, j, std::input_iterator_tag());
}
void ini_idx(const IC& i,const IC& j, std::bidirectional_iterator_tag){
ini_idx( i, j, std::input_iterator_tag());
}
void ini_idx( const IC& i, const IC& j, Forward_circulator_tag) {
ini_idx( i, j, std::input_iterator_tag());
}
void ini_idx( const IC& i, const IC& j, Bidirectional_circulator_tag){
ini_idx( i, j, std::input_iterator_tag());
}
void ini_idx( const IC&, const IC&, std::random_access_iterator_tag){}
void ini_idx( const IC&, const IC&, Random_access_circulator_tag){}
public:
void init_index( const IC& i, const IC& j) {
typedef typename std::iterator_traits<IC>::iterator_category ICC;
ini_idx( i, j, ICC());
}
protected:
void push_back( const IC& k, std::input_iterator_tag) {
std::size_t d = idx.size();
idx[ &*k] = d;
}
void push_back( const IC& k, std::forward_iterator_tag){
push_back( k, std::input_iterator_tag());
}
void push_back( const IC& k, std::bidirectional_iterator_tag){
push_back( k, std::input_iterator_tag());
}
void push_back( const IC& k, Forward_circulator_tag){
push_back( k, std::input_iterator_tag());
}
void push_back( const IC& k, Bidirectional_circulator_tag){
push_back( k, std::input_iterator_tag());
}
void push_back( const IC&, std::random_access_iterator_tag){}
void push_back( const IC&, Random_access_circulator_tag){}
public:
void push_back( const IC& k) {
// adds k at the end of the indices.
typedef typename std::iterator_traits<IC>::iterator_category ICC;
push_back( k, ICC());
}
std::size_t find( const IC& k, std::random_access_iterator_tag) const {
return std::size_t(k - start);
}
std::size_t find( const IC& k, Random_access_circulator_tag) const {
return std::size_t(k - start);
}
std::size_t find( const IC& k, std::input_iterator_tag) const {
// returns inverse index of k.
Index_const_iterator i = idx.find( &*k);
CGAL_assertion( i != idx.end());
return (*i).second;
}
std::size_t find( const IC& k, std::forward_iterator_tag) const {
return find( k, std::input_iterator_tag());
}
std::size_t find( const IC& k, std::bidirectional_iterator_tag) const {
return find( k, std::input_iterator_tag());
}
std::size_t find( const IC& k, Forward_circulator_tag) const {
return find( k, std::input_iterator_tag());
}
std::size_t find( const IC& k, Bidirectional_circulator_tag) const {
return find( k, std::input_iterator_tag());
}
typedef IC iterator;
typedef IC Circulator;
typedef std::size_t size_type;
Inverse_index() : start(IC()) {}
// invalid index.
Inverse_index( const IC& i) : start(i) {};
// empty inverse index initialized to start at i.
Inverse_index( const IC& i, const IC& j) : start(i) {
// inverse index initialized with range [i,j).
init_index( i, j);
}
// OPERATIONS
std::size_t operator[]( const IC& k) const {
// returns inverse index of k.
typedef typename std::iterator_traits<IC>::iterator_category
category;
return find( k, category());
}
};
#if (defined(__GNUC__) && (__GNUC__ >= 3))
template < class IC>
void
Inverse_index< IC>::ini_idx( IC i, const IC& j, std::input_iterator_tag) {
std::size_t n = 0;
if ( ! is_empty_range( i, j)) {
do {
idx.insert(Item( &*i, n));
n++;
} while ((++i) != (j));
}
}
#else
template < class IC>
void
Inverse_index< IC>::ini_idx( IC i, const IC& j, std::input_iterator_tag) {
std::size_t n = 0;
Index_iterator hint = idx.begin();
if ( ! is_empty_range( i, j)) {
do {
hint = idx.insert( hint, Item( &*i, n));
n++;
} while ((++i) != (j));
}
}
#endif // (__GNUC__ >= 3)
template < class IC>
class Random_access_adaptor {
// DEFINITION
//
// The class Random_access_adaptor<IC> provides a random access
// for data structures. Either the data structure supports random access
// iterators or circulators where this class maps function calls to the
// iterator or circulator, or a STL `vector' is used to provide the random
// access. The iterator or circulator of the data structure are of type
// `IC'.
//
// CREATION
protected:
typedef std::vector< IC> Index;
Index index;
IC start;
public:
typedef typename Index::size_type size_type;
void init_index( IC i, const IC& j, std::forward_iterator_tag);
void init_index( const IC& i, const IC& j,
std::bidirectional_iterator_tag){
init_index( i, j, std::forward_iterator_tag());
}
void init_index( const IC& i, const IC&,
std::random_access_iterator_tag){
start = i;
}
void init_index( const IC& i, const IC& j) {
typedef typename std::iterator_traits<IC>::iterator_category ICC;
init_index( i, j, ICC());
}
void reserve( size_type r, std::forward_iterator_tag) {
index.reserve( r);
}
void reserve( size_type r, std::bidirectional_iterator_tag){
reserve( r, std::forward_iterator_tag());
}
void reserve( size_type, std::random_access_iterator_tag){}
void push_back( const IC& k, std::forward_iterator_tag) {
index.push_back(k);
}
void push_back( const IC& k, std::bidirectional_iterator_tag){
push_back( k, std::forward_iterator_tag());
}
void push_back( const IC&, std::random_access_iterator_tag){}
const IC& find( size_type n, std::forward_iterator_tag) const {
// returns inverse index of k.
CGAL_assertion( n < index.size());
return index[n];
}
const IC& find( size_type n, std::bidirectional_iterator_tag) const {
return find( n, std::forward_iterator_tag());
}
IC find( size_type n, std::random_access_iterator_tag) const {
return start + n;
}
typedef IC iterator;
typedef IC Circulator;
Random_access_adaptor() : start(IC()) {}
// invalid index.
Random_access_adaptor( const IC& i) : start(i) {}
// empty random access index initialized to start at i.
Random_access_adaptor( const IC& i, const IC& j) : start(i) {
// random access index initialized with range [i,j).
init_index( i, j);
}
void reserve( size_type r) {
// reserve r entries, if a `vector' is used internally.
typedef typename std::iterator_traits<IC>::iterator_category ICC;
reserve( r, ICC());
}
// OPERATIONS
IC find( size_type n) const {
// returns inverse index of k.
typedef typename std::iterator_traits<IC>::iterator_category ICC;
return find( n, ICC());
}
IC operator[]( size_type n) const { return find(n); }
void push_back( const IC& k) {
// adds k at the end of the indices.
typedef typename std::iterator_traits<IC>::iterator_category ICC;
push_back( k, ICC());
}
};
template < class IC>
void
Random_access_adaptor< IC>::init_index( IC i, const IC& j,
std::forward_iterator_tag) {
if ( ! is_empty_range( i, j)) {
do {
index.push_back( i);
} while ((++i) != (j));
}
}
template < class IC, class T >
class Random_access_value_adaptor : public Random_access_adaptor<IC> {
public:
typedef typename Random_access_adaptor<IC>::size_type size_type;
Random_access_value_adaptor() {}
// invalid index.
Random_access_value_adaptor( const IC& i)
: Random_access_adaptor<IC>(i) {}
// empty random access index initialized to start at i.
Random_access_value_adaptor( const IC& i, const IC& j)
: Random_access_adaptor<IC>(i,j) {}
// random access index initialized with range [i,j).
// OPERATIONS
T& operator[]( size_type n) const {
// returns inverse index of k.
return *(Random_access_adaptor<IC>::operator[](n));
}
};
CGAL_END_NAMESPACE
#endif // CGAL_ITERATOR_H //
// EOF //