path: root/shared/loki/AssocVector.h

////////////////////////////////////////////////////////////////////////////////
// The Loki Library
// Copyright (c) 2001 by Andrei Alexandrescu
// This code accompanies the book:
// Alexandrescu, Andrei. "Modern C++ Design: Generic Programming and Design
//     Patterns Applied". Copyright (c) 2001. Addison-Wesley.
// Permission to use, copy, modify, distribute and sell this software for any
//     purpose is hereby granted without fee, provided that the above copyright
//     notice appear in all copies and that both that copyright notice and this
//     permission notice appear in supporting documentation.
// The author or Addison-Wesley Longman make no representations about the
//     suitability of this software for any purpose. It is provided "as is"
//     without express or implied warranty.
////////////////////////////////////////////////////////////////////////////////
#ifndef LOKI_ASSOCVECTOR_INC_
#define LOKI_ASSOCVECTOR_INC_

// $Id: AssocVector.h 765 2006-10-18 13:55:32Z syntheticpp $


#include <algorithm>
#include <functional>
#include <vector>
#include <utility>

namespace Loki
{
////////////////////////////////////////////////////////////////////////////////
// class template AssocVectorCompare
// Used by AssocVector
////////////////////////////////////////////////////////////////////////////////

namespace Private
{
template <class Value, class C>
class AssocVectorCompare : public C
{
    typedef std::pair<typename C::first_argument_type, Value>
    Data;
    typedef typename C::first_argument_type first_argument_type;

public:
    AssocVectorCompare()
    {}

    AssocVectorCompare(const C& src) : C(src)
    {}

    bool operator()(const first_argument_type& lhs,
                    const first_argument_type& rhs) const
    { return C::operator()(lhs, rhs); }

    bool operator()(const Data& lhs, const Data& rhs) const
    { return operator()(lhs.first, rhs.first); }

    bool operator()(const Data& lhs,
                    const first_argument_type& rhs) const
    { return operator()(lhs.first, rhs); }

    bool operator()(const first_argument_type& lhs,
                    const Data& rhs) const
    { return operator()(lhs, rhs.first); }
};
}

////////////////////////////////////////////////////////////////////////////////
// class template AssocVector
// An associative vector built as a syntactic drop-in replacement for std::map
// BEWARE: AssocVector doesn't respect all map's guarantees, the most important
//     being:
// * iterators are invalidated by insert and erase operations
// * the complexity of insert/erase is O(N) not O(log N)
// * value_type is std::pair<K, V> not std::pair<const K, V>
// * iterators are random
////////////////////////////////////////////////////////////////////////////////


template
<
class K,
      class V,
      class C = std::less<K>,
      class A = std::allocator< std::pair<K, V> >
      >
class AssocVector
    : private std::vector< std::pair<K, V>, A >
    , private Private::AssocVectorCompare<V, C>
{
    typedef std::vector<std::pair<K, V>, A> Base;
    typedef Private::AssocVectorCompare<V, C> MyCompare;

public:
    typedef K key_type;
    typedef V mapped_type;
    typedef typename Base::value_type value_type;

    typedef C key_compare;
    typedef A allocator_type;
    typedef typename A::reference reference;
    typedef typename A::const_reference const_reference;
    typedef typename Base::iterator iterator;
    typedef typename Base::const_iterator const_iterator;
    typedef typename Base::size_type size_type;
    typedef typename Base::difference_type difference_type;
    typedef typename A::pointer pointer;
    typedef typename A::const_pointer const_pointer;
    typedef typename Base::reverse_iterator reverse_iterator;
    typedef typename Base::const_reverse_iterator const_reverse_iterator;

    class value_compare
        : public std::binary_function<value_type, value_type, bool>
        , private key_compare
    {
        friend class AssocVector;

    protected:
        value_compare(key_compare pred) : key_compare(pred)
        {}

    public:
        bool operator()(const value_type& lhs, const value_type& rhs) const
        { return key_compare::operator()(lhs.first, rhs.first); }
    };

    // 23.3.1.1 construct/copy/destroy

    explicit AssocVector(const key_compare& comp = key_compare(),
                         const A& alloc = A())
        : Base(alloc), MyCompare(comp)
    {}

    template <class InputIterator>
    AssocVector(InputIterator first, InputIterator last,
                const key_compare& comp = key_compare(),
                const A& alloc = A())
        : Base(first, last, alloc), MyCompare(comp)
    {
        MyCompare& me = *this;
        std::sort(begin(), end(), me);
    }

    AssocVector& operator=(const AssocVector& rhs)
    {
        AssocVector(rhs).swap(*this);
        return *this;
    }

    // iterators:
    // The following are here because MWCW gets 'using' wrong
    iterator begin() { return Base::begin(); }
    const_iterator begin() const { return Base::begin(); }
    iterator end() { return Base::end(); }
    const_iterator end() const { return Base::end(); }
    reverse_iterator rbegin() { return Base::rbegin(); }
    const_reverse_iterator rbegin() const { return Base::rbegin(); }
    reverse_iterator rend() { return Base::rend(); }
    const_reverse_iterator rend() const { return Base::rend(); }

    // capacity:
    bool empty() const { return Base::empty(); }
    size_type size() const { return Base::size(); }
    size_type max_size() { return Base::max_size(); }

    // 23.3.1.2 element access:
    mapped_type& operator[](const key_type& key)
    { return insert(value_type(key, mapped_type())).first->second; }

    // modifiers:
    std::pair<iterator, bool> insert(const value_type& val)
    {
        bool found(true);
        iterator i(lower_bound(val.first));

        if (i == end() || this->operator()(val.first, i->first))
        {
            i = Base::insert(i, val);
            found = false;
        }
        return std::make_pair(i, !found);
    }
    //Section [23.1.2], Table 69
    //http://developer.apple.com/documentation/DeveloperTools/gcc-3.3/libstdc++/23_containers/howto.html#4
    iterator insert(iterator pos, const value_type& val)
    {
        if ( (pos == begin() || this->operator()(*(pos - 1), val)) &&
             (pos == end()    || this->operator()(val, *pos)) )
        {
            return Base::insert(pos, val);
        }
        return insert(val).first;
    }

    template <class InputIterator>
    void insert(InputIterator first, InputIterator last)
    { for (; first != last; ++first) insert(*first); }

    void erase(iterator pos)
    { Base::erase(pos); }

    size_type erase(const key_type& k)
    {
        iterator i(find(k));
        if (i == end()) return 0;
        erase(i);
        return 1;
    }

    void erase(iterator first, iterator last)
    { Base::erase(first, last); }

    void swap(AssocVector& other)
    {
        Base::swap(other);
        MyCompare& me = *this;
        MyCompare& rhs = other;
        std::swap(me, rhs);
    }

    void clear()
    { Base::clear(); }

    // observers:
    key_compare key_comp() const
    { return *this; }

    value_compare value_comp() const
    {
        const key_compare& comp = *this;
        return value_compare(comp);
    }

    // 23.3.1.3 map operations:
    iterator find(const key_type& k)
    {
        iterator i(lower_bound(k));
        if (i != end() && this->operator()(k, i->first))
        {
            i = end();
        }
        return i;
    }

    const_iterator find(const key_type& k) const
    {
        const_iterator i(lower_bound(k));
        if (i != end() && this->operator()(k, i->first))
        {
            i = end();
        }
        return i;
    }

    size_type count(const key_type& k) const
    { return find(k) != end(); }

    iterator lower_bound(const key_type& k)
    {
        MyCompare& me = *this;
        return std::lower_bound(begin(), end(), k, me);
    }

    const_iterator lower_bound(const key_type& k) const
    {
        const MyCompare& me = *this;
        return std::lower_bound(begin(), end(), k, me);
    }

    iterator upper_bound(const key_type& k)
    {
        MyCompare& me = *this;
        return std::upper_bound(begin(), end(), k, me);
    }

    const_iterator upper_bound(const key_type& k) const
    {
        const MyCompare& me = *this;
        return std::upper_bound(begin(), end(), k, me);
    }

    std::pair<iterator, iterator> equal_range(const key_type& k)
    {
        MyCompare& me = *this;
        return std::equal_range(begin(), end(), k, me);
    }

    std::pair<const_iterator, const_iterator> equal_range(
        const key_type& k) const
    {
        const MyCompare& me = *this;
        return std::equal_range(begin(), end(), k, me);
    }

    template <class K1, class V1, class C1, class A1>
    friend bool operator==(const AssocVector<K1, V1, C1, A1>& lhs,
                           const AssocVector<K1, V1, C1, A1>& rhs);

    bool operator<(const AssocVector& rhs) const
    {
        const Base& me = *this;
        const Base& yo = rhs;
        return me < yo;
    }

    template <class K1, class V1, class C1, class A1>
    friend bool operator!=(const AssocVector<K1, V1, C1, A1>& lhs,
                           const AssocVector<K1, V1, C1, A1>& rhs);

    template <class K1, class V1, class C1, class A1>
    friend bool operator>(const AssocVector<K1, V1, C1, A1>& lhs,
                          const AssocVector<K1, V1, C1, A1>& rhs);

    template <class K1, class V1, class C1, class A1>
    friend bool operator>=(const AssocVector<K1, V1, C1, A1>& lhs,
                           const AssocVector<K1, V1, C1, A1>& rhs);

    template <class K1, class V1, class C1, class A1>
    friend bool operator<=(const AssocVector<K1, V1, C1, A1>& lhs,
                           const AssocVector<K1, V1, C1, A1>& rhs);
};

template <class K, class V, class C, class A>
inline bool operator==(const AssocVector<K, V, C, A>& lhs,
                       const AssocVector<K, V, C, A>& rhs)
{
    const std::vector<std::pair<K, V>, A>& me = lhs;
    return me == rhs;
}

template <class K, class V, class C, class A>
inline bool operator!=(const AssocVector<K, V, C, A>& lhs,
                       const AssocVector<K, V, C, A>& rhs)
{ return !(lhs == rhs); }

template <class K, class V, class C, class A>
inline bool operator>(const AssocVector<K, V, C, A>& lhs,
                      const AssocVector<K, V, C, A>& rhs)
{ return rhs < lhs; }

template <class K, class V, class C, class A>
inline bool operator>=(const AssocVector<K, V, C, A>& lhs,
                       const AssocVector<K, V, C, A>& rhs)
{ return !(lhs < rhs); }

template <class K, class V, class C, class A>
inline bool operator<=(const AssocVector<K, V, C, A>& lhs,
                       const AssocVector<K, V, C, A>& rhs)
{ return !(rhs < lhs); }


// specialized algorithms:
template <class K, class V, class C, class A>
void swap(AssocVector<K, V, C, A>& lhs, AssocVector<K, V, C, A>& rhs)
{ lhs.swap(rhs); }

} // namespace Loki

#endif // end file guardian