frequency_map.hpp

新版本TR1的stl

/* /////////////////////////////////////////////////////////////////////////
 * File:        stlsoft/containers/frequency_map.hpp
 *
 * Purpose:     A container that measures the frequency of the unique elements it contains.
 *
 * Created:     1st October 2005
 * Updated:     5th September 2007
 *
 * Home:        http://stlsoft.org/
 *
 * Copyright (c) 2005-2007, 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.
 *
 * ////////////////////////////////////////////////////////////////////// */


/** \file stlsoft/containers/frequency_map.hpp
 *
 * \brief [C++ only] Definition of the stlsoft::frequency_map container
 *   class template
 *   (\ref group__library__containers "Containers" Library).
 */

#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    0
# define STLSOFT_VER_STLSOFT_CONTAINERS_HPP_FREQUENCY_MAP_REVISION 8
# define STLSOFT_VER_STLSOFT_CONTAINERS_HPP_FREQUENCY_MAP_EDIT     17
#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 */
#include <map>

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

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

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

/** \brief A container that measures the frequency of the unique elements it
 *    contains.
 *
 * \ingroup group__library__containers
 *
 */
template<   ss_typename_param_k T
        ,   ss_typename_param_k N = uint32_t
        >
class frequency_map
    : public stl_collection_tag
{
private:
    typedef stlsoft_ns_qual_std(map)<T, N>                  map_type;

public:
    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;

public: // Construction
    /// Creates an instance of the map
    frequency_map()
    {
        STLSOFT_STATIC_ASSERT(0 != stlsoft::is_integral_type<N>::value);
    }

public: // Modifiers
    /// Pushes an entry onto the map
    ///
    /// If the entry already exists in the map, its count will be increased
    /// by 1. If it does not previously exist, it will be added with an
    /// initial count of one
    ///
    /// \note <b>Thread-safety</b>: it is strongly exception-safe - if an
    ///   entry cannot be added, 
    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 */
    }

    /// Removes all entries from the map
    void clear()
    {
        m_map.clear();
    }

public: // 
    /// Returns an iterator for the entry representing the given key, or
    /// <code>end()</code> if no such entry exists.
    const_iterator find(key_type const& key) const
    {
        return m_map.find(key);
    }

public: // Element Access
    /// Returns the count associated with the entry representing the given
    /// key, or 0 if no such entry exists.
    count_type operator [](key_type const& key) const
    {
        return count(key);
    }

    /// Returns the count associated with the entry representing the given
    /// key, or 0 if no such entry exists.
    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
    /// Indicates whether the map is empty
    ss_bool_t empty() const
    {
        return m_map.empty();
    }

    /// The number of entries in the map
    ///
    /// \remarks This may not be the same as the number of calls to
    ///   <code>push()</code>
    size_type size() const
    {
        return m_map.size();
    }

public:
    /// A non-mutating (const) iterator representing the start of the sequence
    const_iterator begin() const
    {
        return m_map.begin();
    }
    /// A non-mutating (const) iterator representing the end-point of the sequence
    const_iterator end() const
    {
        return m_map.end();
    }

private:
    map_type    m_map;
};

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

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