stlsoft/containers/frequency_map.hpp

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/* /////////////////////////////////////////////////////////////////////////
 * File:        stlsoft/containers/frequency_map.hpp
 *
 * Purpose:     A container that measures the frequency of the unique elements it contains.
 *
 * Created:     1st October 2005
 * Updated:     6th May 2010
 *
 * Home:        http://stlsoft.org/
 *
 * Copyright (c) 2005-2010, Matthew Wilson and Synesis Software
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * - Redistributions of source code must retain the above copyright notice, this
 *   list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright notice,
 *   this list of conditions and the following disclaimer in the documentation
 *   and/or other materials provided with the distribution.
 * - Neither the name(s) of Matthew Wilson and Synesis Software nor the names of
 *   any contributors may be used to endorse or promote products derived from
 *   this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 * ////////////////////////////////////////////////////////////////////// */


#ifndef STLSOFT_INCL_STLSOFT_CONTAINERS_HPP_FREQUENCY_MAP
#define STLSOFT_INCL_STLSOFT_CONTAINERS_HPP_FREQUENCY_MAP

#ifndef STLSOFT_DOCUMENTATION_SKIP_SECTION
# define STLSOFT_VER_STLSOFT_CONTAINERS_HPP_FREQUENCY_MAP_MAJOR    2
# define STLSOFT_VER_STLSOFT_CONTAINERS_HPP_FREQUENCY_MAP_MINOR    1
# define STLSOFT_VER_STLSOFT_CONTAINERS_HPP_FREQUENCY_MAP_REVISION 1
# define STLSOFT_VER_STLSOFT_CONTAINERS_HPP_FREQUENCY_MAP_EDIT     23
#endif /* !STLSOFT_DOCUMENTATION_SKIP_SECTION */

/* /////////////////////////////////////////////////////////////////////////
 * Auto-generation and compatibility
 */

/* /////////////////////////////////////////////////////////////////////////
 * Includes
 */

#ifndef STLSOFT_INCL_STLSOFT_H_STLSOFT
# include <stlsoft/stlsoft.h>
#endif /* !STLSOFT_INCL_STLSOFT_H_STLSOFT */
#ifndef STLSOFT_INCL_STLSOFT_COLLECTIONS_UTIL_HPP_COLLECTIONS
# include <stlsoft/collections/util/collections.hpp>
#endif /* !STLSOFT_INCL_STLSOFT_COLLECTIONS_UTIL_HPP_COLLECTIONS */
#ifndef STLSOFT_INCL_STLSOFT_META_HPP_IS_INTEGRAL_TYPE
# include <stlsoft/meta/is_integral_type.hpp>
#endif /* !STLSOFT_INCL_STLSOFT_META_HPP_IS_INTEGRAL_TYPE */
#ifndef STLSOFT_INCL_STLSOFT_UTIL_HPP_STD_SWAP
# include <stlsoft/util/std_swap.hpp>
#endif /* !STLSOFT_INCL_STLSOFT_UTIL_HPP_STD_SWAP */

#ifndef STLSOFT_INCL_MAP
# define STLSOFT_INCL_MAP
# include <map>
#endif /* !STLSOFT_INCL_MAP */

/* /////////////////////////////////////////////////////////////////////////
 * Namespace
 */

#ifndef _STLSOFT_NO_NAMESPACE
namespace stlsoft
{
#endif /* _STLSOFT_NO_NAMESPACE */

/* /////////////////////////////////////////////////////////////////////////
 * Classes
 */

template<   ss_typename_param_k T
#if defined(STLSOFT_COMPILER_IS_MSVC) && \
    _MSC_VER < 1300
        ,   ss_typename_param_k N = unsigned int
#else
        ,   ss_typename_param_k N = uint32_t
#endif
        >
class frequency_map
    : public stl_collection_tag
{
private: // Member Types
    typedef stlsoft_ns_qual_std(map)<T, N>                  map_type_;
public:
    typedef frequency_map<T, N>                             class_type;
    typedef ss_typename_param_k map_type_::value_type       value_type;
    typedef ss_typename_param_k map_type_::const_iterator   const_iterator;
//    typedef ss_typename_param_k map_type_::const_pointer    const_pointer;
    typedef ss_typename_param_k map_type_::const_reference  const_reference;

    typedef ss_typename_param_k map_type_::key_type         key_type;
//    typedef ss_typename_param_k map_type_::mapped_type      mapped_type
    typedef N                                               count_type;
    typedef ss_size_t                                       size_type;
    typedef ss_ptrdiff_t                                    difference_type;
    typedef ss_bool_t                                       bool_type;

public: // Construction
    frequency_map()
    {
        STLSOFT_STATIC_ASSERT(0 != stlsoft::is_integral_type<N>::value);
    }

public: // Modifiers
    count_type push(key_type const& key)
    {
        return ++m_map[key];

#if 0
        // NOTE: Because the count type N must be an integer, the code above
        // is equivalent to the following "full" thread-safe implementation.
        ss_typename_param_k map_type_::iterator it = m_map.find(key);
        if(m_map.end() == it)
        {
            value_type  value(key, 1);

            m_map.insert(value);

            return 1;
        }
        else
        {
            value_type& value = *it;

            return ++(*it).second;
        }
#endif /* 0 */
    }

    void clear()
    {
        m_map.clear();
    }

    class_type& merge(class_type const& rhs)
    {
        class_type  t(*this);

        { for(const_iterator i = rhs.begin(); i != rhs.end(); ++i)
        {
            t.m_map[(*i).first] += (*i).second;
        }}

        t.swap(*this);

        return *this;
    }

    void swap(class_type& rhs) stlsoft_throw_0()
    {
        std_swap(m_map, rhs.m_map);
    }

public: // Search
    const_iterator find(key_type const& key) const
    {
        return m_map.find(key);
    }

public: // Element Access
    count_type operator [](key_type const& key) const
    {
        return count(key);
    }

    count_type count(key_type const& key) const
    {
        const_iterator it = m_map.find(key);

        return (m_map.end() != it) ? (*it).second : 0;
    }

public: // Size
    bool_type empty() const
    {
        return m_map.empty();
    }

    size_type size() const
    {
        return m_map.size();
    }

public: // Iteration
    const_iterator begin() const
    {
        return m_map.begin();
    }
    const_iterator end() const
    {
        return m_map.end();
    }

private: // Member Variables
    map_type_   m_map;
};

/* /////////////////////////////////////////////////////////////////////////
 * swapping
 */

#if !defined(STLSOFT_COMPILER_IS_WATCOM)

template<   ss_typename_param_k T
        ,   ss_typename_param_k N
        >
inline void swap(
    frequency_map<T, N>& lhs
,   frequency_map<T, N>& rhs
)
{
    lhs.swap(rhs);
}
#endif /* compiler */

/* /////////////////////////////////////////////////////////////////////////
 * Unit-testing
 */

#ifdef STLSOFT_UNITTEST
# include "./unittest/frequency_map_unittest_.h"
#endif /* STLSOFT_UNITTEST */

/* ////////////////////////////////////////////////////////////////////// */

#ifndef _STLSOFT_NO_NAMESPACE
} // namespace stlsoft
#endif /* _STLSOFT_NO_NAMESPACE */

/* ////////////////////////////////////////////////////////////////////// */

#endif /* !STLSOFT_INCL_STLSOFT_CONTAINERS_HPP_FREQUENCY_MAP */

/* ///////////////////////////// end of file //////////////////////////// */

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