transform_iterator.hpp

新版本TR1的stl

/// \name Bidirectional Iterator methods
/// @{
public:
    class_type& operator --()
    {
        ++m_it;

        return *this;
    }
    class_type operator --(int)
    {
        class_type  ret(*this);

        operator --();

        return ret;
    }
/// @}

#ifndef STLSOFT_ITER_TXFM_ITER_OLD_DW
/// \name Random Access Iterator methods
/// @{
public:
    class_type& operator +=(difference_type d)
    {
        m_it += d;

        return *this;
    }
    class_type& operator -=(difference_type d)
    {
        m_it -= d;

        return *this;
    }

    // NOTE: Can't be reference, since what would it reference??
    effective_reference         operator [](difference_type index)
    {
        return m_transformer(m_it[index]);
    }
    // NOTE: Can't be reference, since what would it reference??
    effective_const_reference   operator [](difference_type index) const
    {
        return m_transformer(m_it[index]);
    }
/// @}
#endif /* !STLSOFT_ITER_TXFM_ITER_OLD_DW */

/// \name Comparison
/// @{
public:
    /// Evaluates whether \c this and \c rhs are equivalent
    ss_bool_t equal(class_type const& rhs) const
    {
        return m_it == rhs.m_it;
    }
#if 0
    ss_bool_t equal(iterator_type rhs) const
    {
        return m_it == rhs;
    }
#endif /* 0 */
    /// Compares \c this with the given string
    ss_sint_t compare(class_type const& rhs) const
    {
        return (m_it < rhs.m_it) ? -1 : (rhs.m_it < m_it) ? +1 : 0;
    }
#ifndef STLSOFT_ITER_TXFM_ITER_OLD_DW
    /// Calculate the distance between \c this and \c rhs
    difference_type distance(class_type const& rhs) const
    {
        return m_it - rhs.m_it;
    }
#endif /* !STLSOFT_ITER_TXFM_ITER_OLD_DW */
/// @}

/// \name Members
/// @{
private:
#if 0
public:
#endif /* 0 */
    iterator_type           m_it;
private:
    transform_function_type m_transformer;
    value_type              m_current;
/// @}

/// \name Not to be implemented
/// @{
private:
    struct transform_iterator_is_BVT_so_no_member_selection_operators
    {};

    transform_iterator_is_BVT_so_no_member_selection_operators *operator ->() const;
/// @}
};

/* /////////////////////////////////////////////////////////////////////////
 * Creator functions
 */

/** \brief Creator function for transform_iterator
 *
 * \ingroup group__library__iterators
 *
 * \param it The iterator to transform
 * \param fn The function object used to effect the transformation
 *
 * \return An instance of the specialisation transform_iterator&lt;T, F&gt;
 */
template<   ss_typename_param_k I
        ,   ss_typename_param_k F
        >
inline transform_iterator<I, F> make_transform_iterator(I it, F fn)
{
    return transform_iterator<I, F>(it, fn);
}

/** \brief Creator function for transform_iterator
 *
 * \ingroup group__library__iterators
 *
 * \param it The iterator to transform
 * \param fn The function object used to effect the transformation
 *
 * \return An instance of the specialisation transform_iterator&lt;T, F&gt;
 *
 * \note Short-hand for make_transform_iterator()
 */
template<   ss_typename_param_k I
        ,   ss_typename_param_k F
        >
inline transform_iterator<I, F> transformer(I it, F fn)
{
    return make_transform_iterator(it, fn);
}

#if 0
template<   ss_typename_param_k I
        >
inline transform_iterator<I, null_function> transformer(I it)
{
    return transform_iterator<I, null_function>(it, null_function());
}
#endif

#if 0
template<   ss_typename_param_k I
        ,   ss_typename_param_k F
        >
inline transform_iterator<I, F> transform(I it, F fn)
{
    return transform_iterator<I, F>(it, fn);
}
#endif /* 0 */

/* /////////////////////////////////////////////////////////////////////////
 * Operators
 */

// operator ==

template<   ss_typename_param_k I
        ,   ss_typename_param_k F
        >
inline ss_bool_t operator ==(transform_iterator<I, F> const& lhs, transform_iterator<I, F> const& rhs)
{
    return lhs.equal(rhs);
}

// operator !=

template<   ss_typename_param_k I
        ,   ss_typename_param_k F
        >
inline ss_bool_t operator !=(transform_iterator<I, F> const& lhs, transform_iterator<I, F> const& rhs)
{
    return !lhs.equal(rhs);
}

#if 0
template<   ss_typename_param_k I
        ,   ss_typename_param_k F
        >
inline ss_bool_t operator !=(transform_iterator<I, F> const& lhs, I rhs)
{
    return !lhs.equal(rhs);
}
#endif /* 0 */

#ifndef STLSOFT_ITER_TXFM_ITER_OLD_DW
// operator +

template<   ss_typename_param_k I
        ,   ss_typename_param_k F
        >
inline transform_iterator<I, F> operator +(transform_iterator<I, F> const& lhs, ss_typename_type_k transform_iterator<I, F>::difference_type rhs)
{
    return transform_iterator<I, F>(lhs) += rhs;
}

// operator -

template<   ss_typename_param_k I
        ,   ss_typename_param_k F
        >
#if 0
inline transform_iterator<I, F> operator -(transform_iterator<I, F> const& lhs, ss_typename_type_k transform_iterator<I, F>::difference_type rhs)
#else /* ? 0 */
inline transform_iterator<I, F> operator -(transform_iterator<I, F> const& lhs, ss_ptrdiff_t rhs)
#endif /* 0 */
{
    return transform_iterator<I, F>(lhs) -= rhs;
}

template<   ss_typename_param_k I
        ,   ss_typename_param_k F
        >
inline ss_typename_type_k transform_iterator<I, F>::difference_type operator -(transform_iterator<I, F> const& lhs, transform_iterator<I, F> const& rhs)
{
    return lhs.distance(rhs);
}

// operator <

template<   ss_typename_param_k I
        ,   ss_typename_param_k F
        >
inline ss_bool_t operator <(transform_iterator<I, F> const& lhs, transform_iterator<I, F> const& rhs)
{
    return lhs.compare(rhs) < 0;
}

// operator <=

template<   ss_typename_param_k I
        ,   ss_typename_param_k F
        >
inline ss_bool_t operator <=(transform_iterator<I, F> const& lhs, transform_iterator<I, F> const& rhs)
{
    return lhs.compare(rhs) <= 0;
}

// operator >

template<   ss_typename_param_k I
        ,   ss_typename_param_k F
        >
inline ss_bool_t operator >(transform_iterator<I, F> const& lhs, transform_iterator<I, F> const& rhs)
{
    return lhs.compare(rhs) > 0;
}

// operator >=

template<   ss_typename_param_k I
        ,   ss_typename_param_k F
        >
inline ss_bool_t operator >=(transform_iterator<I, F> const& lhs, transform_iterator<I, F> const& rhs)
{
    return lhs.compare(rhs) >= 0;
}

#endif /* !STLSOFT_ITER_TXFM_ITER_OLD_DW */

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

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

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

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

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

#endif /* !STLSOFT_INCL_STLSOFT_ITERATORS_HPP_TRANSFORM_ITERATOR */

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