vector_expression.hpp

C++的一个好库。。。现在很流行

//
//  Copyright (c) 2000-2002
//  Joerg Walter, Mathias Koch
//
//  Permission to use, copy, modify, distribute and sell this software
//  and its documentation 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 authors make no representations
//  about the suitability of this software for any purpose.
//  It is provided "as is" without express or implied warranty.
//
//  The authors gratefully acknowledge the support of
//  GeNeSys mbH & Co. KG in producing this work.
//

#ifndef _BOOST_UBLAS_VECTOR_EXPRESSION_
#define _BOOST_UBLAS_VECTOR_EXPRESSION_

#include <boost/numeric/ublas/expression_types.hpp>


// Expression templates based on ideas of Todd Veldhuizen and Geoffrey Furnish
// Iterators based on ideas of Jeremy Siek
//
// Classes that model the Vector Expression concept

namespace boost { namespace numeric { namespace ublas {

    template<class E>
    class vector_reference:
        public vector_expression<vector_reference<E> > {

        typedef vector_reference<E> self_type;
    public:
#ifdef BOOST_UBLAS_ENABLE_PROXY_SHORTCUTS
        using vector_expression<vector_reference<E> >::operator ();
#endif
        typedef typename E::size_type size_type;
        typedef typename E::difference_type difference_type;
        typedef typename E::value_type value_type;
        typedef typename E::const_reference const_reference;
        typedef typename boost::mpl::if_<boost::is_const<E>,
                                          typename E::const_reference,
                                          typename E::reference>::type reference;
        typedef E refered_type;
        typedef const self_type const_closure_type;
        typedef const_closure_type closure_type;
        typedef typename E::storage_category storage_category;

        // Construction and destruction
        BOOST_UBLAS_INLINE
        explicit vector_reference (refered_type &e):
            e_ (e) {}

        // Accessors
        BOOST_UBLAS_INLINE
        size_type size () const {
            return expression ().size ();
        }

    public:
        // Expression accessors - const correct
        BOOST_UBLAS_INLINE
        const refered_type &expression () const {
            return e_;
        }
        BOOST_UBLAS_INLINE
        refered_type &expression () {
            return e_;
        }

    public:
        // Element access
#ifndef BOOST_UBLAS_REFERENCE_CONST_MEMBER
        BOOST_UBLAS_INLINE
        const_reference operator () (size_type i) const {
            return expression () (i);
        }
        BOOST_UBLAS_INLINE
        reference operator () (size_type i) {
            return expression () (i);
        }

        BOOST_UBLAS_INLINE
        const_reference operator [] (size_type i) const {
            return expression () [i];
        }
        BOOST_UBLAS_INLINE
        reference operator [] (size_type i) {
            return expression () [i];
        }
#else
        BOOST_UBLAS_INLINE
        reference operator () (size_type i) const {
            return expression () (i);
        }

        BOOST_UBLAS_INLINE
        reference operator [] (size_type i) const {
            return expression () [i];
        }
#endif

        // Assignment
        BOOST_UBLAS_INLINE
        vector_reference &operator = (const vector_reference &v) {
            expression ().operator = (v);
            return *this;
        }
        template<class AE>
        BOOST_UBLAS_INLINE
        vector_reference &operator = (const vector_expression<AE> &ae) {
            expression ().operator = (ae);
            return *this;
        }
        template<class AE>
        BOOST_UBLAS_INLINE
        vector_reference &assign (const vector_expression<AE> &ae) {
            expression ().assign (ae);
            return *this;
        }
        template<class AE>
        BOOST_UBLAS_INLINE
        vector_reference &operator += (const vector_expression<AE> &ae) {
            expression ().operator += (ae);
            return *this;
        }
        template<class AE>
        BOOST_UBLAS_INLINE
        vector_reference &plus_assign (const vector_expression<AE> &ae) {
            expression ().plus_assign (ae);
            return *this;
        }
        template<class AE>
        BOOST_UBLAS_INLINE
        vector_reference &operator -= (const vector_expression<AE> &ae) {
            expression ().operator -= (ae);
            return *this;
        }
        template<class AE>
        BOOST_UBLAS_INLINE
        vector_reference &minus_assign (const vector_expression<AE> &ae) {
            expression ().minus_assign (ae);
            return *this;
        }
        template<class AT>
        BOOST_UBLAS_INLINE
        vector_reference &operator *= (const AT &at) {
            expression ().operator *= (at);
            return *this;
        }
        template<class AT>
        BOOST_UBLAS_INLINE
        vector_reference &operator /= (const AT &at) {
            expression ().operator /= (at);
            return *this;
        }

        // Swapping
        BOOST_UBLAS_INLINE
        void swap (vector_reference &v) {
            expression ().swap (v.expression ());
        }

        // Closure comparison
        BOOST_UBLAS_INLINE
        bool same_closure (const vector_reference &vr) const {
            return &(*this).e_ == &vr.e_;
        }

        // Iterator types
        typedef typename E::const_iterator const_iterator;
        typedef typename boost::mpl::if_<boost::is_const<E>,
                                          typename E::const_iterator,
                                          typename E::iterator>::type iterator;

        // Element lookup
        BOOST_UBLAS_INLINE
        const_iterator find (size_type i) const {
            return expression ().find (i);
        }
        BOOST_UBLAS_INLINE
        iterator find (size_type i) {
            return expression ().find (i);
        }

        // Iterator is the iterator of the referenced expression.

        BOOST_UBLAS_INLINE
        const_iterator begin () const {
            return expression ().begin ();
        }
        BOOST_UBLAS_INLINE
        const_iterator end () const {
            return expression ().end ();
        }

        BOOST_UBLAS_INLINE
        iterator begin () {
            return expression ().begin ();
        }
        BOOST_UBLAS_INLINE
        iterator end () {
            return expression ().end ();
        }

        // Reverse iterator
        typedef reverse_iterator_base<const_iterator> const_reverse_iterator;
        typedef reverse_iterator_base<iterator> reverse_iterator;

        BOOST_UBLAS_INLINE
        const_reverse_iterator rbegin () const {
            return const_reverse_iterator (end ());
        }
        BOOST_UBLAS_INLINE
        const_reverse_iterator rend () const {
            return const_reverse_iterator (begin ());
        }
        BOOST_UBLAS_INLINE
        reverse_iterator rbegin () {
            return reverse_iterator (end ());
        }
        BOOST_UBLAS_INLINE
        reverse_iterator rend () {
            return reverse_iterator (begin ());
        }

    private:
        refered_type &e_;
    };


    template<class E, class F>
    class vector_unary:
        public vector_expression<vector_unary<E, F> > {

        typedef F functor_type;
        typedef typename boost::mpl::if_<boost::is_same<F, scalar_identity<typename E::value_type> >,
                                          E,
                                          const E>::type expression_type;
        typedef typename boost::mpl::if_<boost::is_const<expression_type>,
                                          typename E::const_closure_type,
                                          typename E::closure_type>::type expression_closure_type;
        typedef vector_unary<E, F> self_type;
    public:
#ifdef BOOST_UBLAS_ENABLE_PROXY_SHORTCUTS
        using vector_expression<vector_unary<E, F> >::operator ();
#endif
        typedef typename E::size_type size_type;
        typedef typename E::difference_type difference_type;
        typedef typename F::result_type value_type;
        typedef value_type const_reference;
        typedef typename boost::mpl::if_<boost::is_same<F, scalar_identity<value_type> >,
                                          typename E::reference,
                                          value_type>::type reference;
        typedef const self_type const_closure_type;
        typedef self_type closure_type;
        typedef unknown_storage_tag storage_category;

        // Construction and destruction
        BOOST_UBLAS_INLINE
        // May be used as mutable expression.
        explicit vector_unary (expression_type &e):
            e_ (e) {}

        // Accessors
        BOOST_UBLAS_INLINE
        size_type size () const {
            return e_.size ();
        }

    public:
        // Expression accessors
        BOOST_UBLAS_INLINE
        const expression_closure_type &expression () const {
            return e_;
        }

    public:
        // Element access
        BOOST_UBLAS_INLINE
        const_reference operator () (size_type i) const {
            return functor_type::apply (e_ (i));
        }
        BOOST_UBLAS_INLINE
        reference operator () (size_type i) {
            BOOST_STATIC_ASSERT ((boost::is_same<functor_type, scalar_identity<value_type > >::value));
            return e_ (i);
        }

        BOOST_UBLAS_INLINE
        const_reference operator [] (size_type i) const {
            return functor_type::apply (e_ [i]);
        }
        BOOST_UBLAS_INLINE
        reference operator [] (size_type i) {
            BOOST_STATIC_ASSERT ((boost::is_same<functor_type, scalar_identity<value_type > >::value));
            return e_ [i];
        }

        // Closure comparison
        BOOST_UBLAS_INLINE
        bool same_closure (const vector_unary &vu) const {
            return (*this).expression ().same_closure (vu.expression ());
        }

        // Iterator types
    private:
        typedef typename E::const_iterator const_subiterator_type;
        typedef const value_type *const_pointer;

    public:
#ifdef BOOST_UBLAS_USE_INDEXED_ITERATOR
        typedef indexed_const_iterator<const_closure_type, typename const_subiterator_type::iterator_category> const_iterator;
        typedef const_iterator iterator;
#else
        class const_iterator;
        typedef const_iterator iterator;
#endif