boost/multi_index/detail/rnd_index_node.hpp
/* Copyright 2003-2006 Joaqu�n M L�pez Mu�oz.
* Distributed under the Boost Software License, Version 1.0.
* (See accompanying file LICENSE_1_0.txt or copy at
* http://www.boost.org/LICENSE_1_0.txt)
*
* See http://www.boost.org/libs/multi_index for library home page.
*/
#ifndef BOOST_MULTI_INDEX_DETAIL_RND_INDEX_NODE_HPP
#define BOOST_MULTI_INDEX_DETAIL_RND_INDEX_NODE_HPP
#if defined(_MSC_VER)&&(_MSC_VER>=1200)
#pragma once
#endif
#include <boost/config.hpp> /* keep it first to prevent nasty warns in MSVC */
#include <algorithm>
#include <boost/math/common_factor_rt.hpp>
#include <cstddef>
#include <functional>
namespace boost{
namespace multi_index{
namespace detail{
struct random_access_index_node_impl
{
random_access_index_node_impl**& up(){return up_;}
random_access_index_node_impl** up()const{return up_;}
/* interoperability with rnd_node_iterator */
static void increment(random_access_index_node_impl*& x)
{
x=*(x->up()+1);
}
static void decrement(random_access_index_node_impl*& x)
{
x=*(x->up()-1);
}
static void advance(
random_access_index_node_impl*& x,std::ptrdiff_t n)
{
x=*(x->up()+n);
}
static std::ptrdiff_t distance(
random_access_index_node_impl* x,random_access_index_node_impl* y)
{
return y->up()-x->up();
}
/* algorithmic stuff */
static void relocate(
random_access_index_node_impl** pos,
random_access_index_node_impl** x)
{
random_access_index_node_impl* n=*x;
if(x<pos){
extract(x,pos);
*(pos-1)=n;
n->up()=pos-1;
}
else{
while(x!=pos){
*x=*(x-1);
(*x)->up()=x;
--x;
}
*pos=n;
n->up()=pos;
}
};
static void relocate(
random_access_index_node_impl** pos,
random_access_index_node_impl** first,
random_access_index_node_impl** last)
{
random_access_index_node_impl** begin,**middle,**end;
if(pos<first){
begin=pos;
middle=first;
end=last;
}
else{
begin=first;
middle=last;
end=pos;
}
std::ptrdiff_t n=end-begin;
std::ptrdiff_t m=middle-begin;
std::ptrdiff_t n_m=n-m;
std::ptrdiff_t p=math::gcd(n,m);
for(std::ptrdiff_t i=0;i<p;++i){
random_access_index_node_impl* tmp=begin[i];
for(std::ptrdiff_t j=i,k;;){
if(j<n_m)k=j+m;
else k=j-n_m;
if(k==i){
begin[j]=tmp;
begin[j]->up()=&begin[j];
break;
}
else{
begin[j]=begin[k];
begin[j]->up()=&begin[j];
}
if(k<n_m)j=k+m;
else j=k-n_m;
if(j==i){
begin[k]=tmp;
begin[k]->up()=&begin[k];
break;
}
else{
begin[k]=begin[j];
begin[k]->up()=&begin[k];
}
}
}
};
static void extract(
random_access_index_node_impl** x,
random_access_index_node_impl** pend)
{
--pend;
while(x!=pend){
*x=*(x+1);
(*x)->up()=x;
++x;
}
}
static void transfer(
random_access_index_node_impl** pbegin0,
random_access_index_node_impl** pend0,
random_access_index_node_impl** pbegin1)
{
while(pbegin0!=pend0){
*pbegin1=*pbegin0++;
(*pbegin1)->up()=pbegin1;
++pbegin1;
}
}
static void reverse(
random_access_index_node_impl** pbegin,
random_access_index_node_impl** pend)
{
std::ptrdiff_t d=(pend-pbegin)/2;
for(std::ptrdiff_t i=0;i<d;++i){
std::swap(*pbegin,*--pend);
(*pbegin)->up()=pbegin;
(*pend)->up()=pend;
++pbegin;
}
}
private:
random_access_index_node_impl** up_;
};
template<typename Super>
struct random_access_index_node_trampoline:random_access_index_node_impl{};
template<typename Super>
struct random_access_index_node:
Super,random_access_index_node_trampoline<Super>
{
random_access_index_node_impl**& up(){return impl_type::up();}
random_access_index_node_impl** up()const{return impl_type::up();}
random_access_index_node_impl* impl()
{return static_cast<impl_type*>(this);}
const random_access_index_node_impl* impl()const
{return static_cast<const impl_type*>(this);}
static random_access_index_node* from_impl(random_access_index_node_impl *x)
{
return static_cast<random_access_index_node*>(
static_cast<impl_type*>(x));
}
static const random_access_index_node* from_impl(
const random_access_index_node_impl* x)
{
return static_cast<const random_access_index_node*>(
static_cast<const impl_type*>(x));
}
/* interoperability with rnd_node_iterator */
static void increment(random_access_index_node*& x)
{
random_access_index_node_impl* xi=x->impl();
impl_type::increment(xi);
x=from_impl(xi);
}
static void decrement(random_access_index_node*& x)
{
random_access_index_node_impl* xi=x->impl();
impl_type::decrement(xi);
x=from_impl(xi);
}
static void advance(random_access_index_node*& x,std::ptrdiff_t n)
{
random_access_index_node_impl* xi=x->impl();
impl_type::advance(xi,n);
x=from_impl(xi);
}
static std::ptrdiff_t distance(
random_access_index_node* x,random_access_index_node* y)
{
return impl_type::distance(x->impl(),y->impl());
}
private:
typedef random_access_index_node_trampoline<Super> impl_type;
};
} /* namespace multi_index::detail */
} /* namespace multi_index */
} /* namespace boost */
#endif