Files
cgal/Hash_map/include/CGAL/Unique_hash_map.h
T
Mael Rouxel-Labbé 590ddf8015 Various fixes for pmaps:
- Use `value_type` when the returned type is not a reference
- Enforce `reference = value_type` if the returned type is not
  a reference (to avoid `typename PM::reference r = get(m, k)`,
  which will take a ref to a temporary if the `reference`
  typedef is an actualy reference)
- Do not use `put_get_helper` if the property map is not a `lvalue`
  **mutable** property map: the `put()` is `map[k] = v`, which
  is broken if `operator[]` does not return a reference
- The concept `boost::lvalue_property_map_tag` requires `operator[](key)`,
  not a reference in `get(map, key)`. You can have a readable property map
  returning a reference through its `get(map, key)`, but if there is
  no `operator[]`, it's just a `boost::readable_property_map_tag`
- Some const correctness to avoid copying maps with state
  or heavy keys in `get(map, key)` / `put(map, key, value)`
- Base the category of a wrapping pmap on what it offers instead
  of just forwarding the base property map's category
- Tried to do something like mutable lvalue pmap:
  * `value_type& operator[](key&)`
  * `ref get(map, const key&)`
  * `put(map, const key&, const value_type&)`
  and non-mutable lvalue pmap:
  * `const value_type& operator[](const key&)`
  * `ref get(map, const key&)`
  but not everything fits properly...
2021-10-08 15:38:47 +02:00

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C++

// Copyright (c) 1997-2000
// Utrecht University (The Netherlands),
// ETH Zurich (Switzerland),
// INRIA Sophia-Antipolis (France),
// Max-Planck-Institute Saarbruecken (Germany),
// and Tel-Aviv University (Israel). All rights reserved.
//
// This file is part of CGAL (www.cgal.org)
//
// $URL$
// $Id$
// SPDX-License-Identifier: LGPL-3.0-or-later OR LicenseRef-Commercial
//
//
// Author(s) : Michael Seel <seel@mpi-sb.mpg.de>
// Lutz Kettner <kettner@inf.ethz.ch>
#ifndef CGAL_UNIQUE_HASH_MAP_H
#define CGAL_UNIQUE_HASH_MAP_H
#include <CGAL/disable_warnings.h>
#include <CGAL/config.h>
#include <CGAL/memory.h>
#include <CGAL/Handle_hash_function.h>
#include <CGAL/Tools/chained_map.h>
#include <cstddef>
namespace CGAL {
template <class Key_, class Data_,
class UniqueHashFunction = Handle_hash_function,
class Allocator_ = CGAL_ALLOCATOR(Data_) >
class Unique_hash_map {
public:
typedef Key_ Key;
typedef Data_ Data;
typedef UniqueHashFunction Hash_function;
typedef Allocator_ Allocator;
// STL compliance
typedef Key_ key_type;
typedef Data_ data_type;
typedef UniqueHashFunction hasher;
typedef Unique_hash_map<Key,Data,Hash_function,Allocator> Self;
private:
typedef internal::chained_map<Data, Allocator> Map;
typedef typename Map::item Item;
private:
Hash_function m_hash_function;
Map m_map;
public:
Unique_hash_map() { m_map.xdef() = Data(); }
Unique_hash_map( const Data& deflt, std::size_t table_size = 1)
: m_map( table_size) { m_map.xdef() = deflt; }
Unique_hash_map( const Data& deflt,
std::size_t table_size,
const Hash_function& fct)
: m_hash_function(fct), m_map( table_size) { m_map.xdef() = deflt; }
Unique_hash_map( Key first1, Key beyond1, Data first2) {
m_map.xdef() = Data();
insert( first1, beyond1, first2);
}
Unique_hash_map( Key first1, Key beyond1, Data first2,
const Data& deflt,
std::size_t table_size = 1,
const Hash_function& fct = Hash_function())
: m_hash_function(fct), m_map( table_size) {
m_map.xdef() = deflt;
insert( first1, beyond1, first2);
}
Data default_value() const { return m_map.cxdef(); }
Hash_function hash_function() const { return m_hash_function; }
void clear() { m_map.clear(); }
void clear( const Data& deflt) {
m_map.clear();
m_map.xdef() = deflt; }
bool is_defined( const Key& key) const {
return m_map.lookup( m_hash_function(key)) != 0;
}
const Data& operator[]( const Key& key) const {
Item p = m_map.lookup( m_hash_function(key));
if ( p != 0 )
return m_map.inf(p);
return m_map.cxdef();
}
Data& operator[]( const Key& key) {
return m_map.access( m_hash_function(key));
}
Data insert( Key first1, Key beyond1, Data first2) {
for ( ; first1 != beyond1; (++first1, ++first2)) {
operator[]( first1) = first2;
}
return first2;
}
void statistics() const { m_map.statistics(); }
};
} //namespace CGAL
namespace boost {
template <typename UniquePairAssociativeContainer>
class associative_property_map;
struct lvalue_property_map_tag;
template <typename KeyType, typename ValueType,
typename HashFunction, typename Allocator>
class associative_property_map<CGAL::Unique_hash_map<KeyType, ValueType,
HashFunction, Allocator> >
{
typedef CGAL::Unique_hash_map<KeyType, ValueType, HashFunction, Allocator> C;
public:
typedef KeyType key_type;
typedef ValueType value_type;
typedef value_type& reference;
typedef lvalue_property_map_tag category;
associative_property_map() : m_c(0) { }
associative_property_map(C& c) : m_c(&c) { }
reference operator[](const key_type& k) const {
return (*m_c)[k];
}
friend
reference
get(const associative_property_map<C>& uhm, const key_type& key)
{
return uhm[key];
}
friend
void
put(associative_property_map<C>& uhm, const key_type& key, const value_type& val)
{
uhm[key] = val;
}
private:
C* m_c;
};
template <typename KeyType, typename ValueType,
typename HashFunction, typename Allocator>
associative_property_map<CGAL::Unique_hash_map<KeyType, ValueType,
HashFunction, Allocator> >
make_assoc_property_map(CGAL::Unique_hash_map<KeyType, ValueType,
HashFunction, Allocator>& c)
{
return associative_property_map<CGAL::Unique_hash_map<KeyType, ValueType,
HashFunction, Allocator> >(c);
}
}
#include <CGAL/enable_warnings.h>
#endif // CGAL_UNIQUE_HASH_MAP_H
// EOF