3 * Interface to GiNaC's light-weight expression handles. */
6 * GiNaC Copyright (C) 1999-2004 Johannes Gutenberg University Mainz, Germany
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 #ifndef __GINAC_EX_H__
24 #define __GINAC_EX_H__
37 /** Helper class to initialize the library. There must be one static object
38 * of this class in every object file that makes use of our flyweights in
39 * order to guarantee proper initialization. Hence we put it into this
40 * file which is included by every relevant file anyways. This is modeled
41 * after section 27.4.2.1.6 of the C++ standard, where cout and friends are
52 /** For construction of flyweights, etc. */
53 static library_init library_initializer;
56 class scalar_products;
58 class const_preorder_iterator;
59 class const_postorder_iterator;
62 /** Lightweight wrapper for GiNaC's symbolic objects. Basically all it does is
63 * to hold a pointer to the other objects, manage the reference counting and
64 * provide methods for manipulation of these objects. (Some people call such
65 * a thing a proxy class.) */
67 friend class archive_node;
68 friend inline bool are_ex_trivially_equal(const ex &, const ex &);
69 template<class T> friend inline const T &ex_to(const ex &);
70 template<class T> friend inline bool is_a(const ex &);
71 template<class T> friend inline bool is_exactly_a(const ex &);
73 // default constructor, copy constructor and assignment operator
76 #ifdef OBSCURE_CINT_HACK
78 ex & operator=(const ex & other);
83 ex(const basic & other);
90 /** Construct ex from string and a list of symbols. The input grammar is
91 * similar to the GiNaC output format. All symbols and indices to be used
92 * in the expression must be specified in a lst in the second argument.
93 * Undefined symbols and other parser errors will throw an exception. */
94 ex(const std::string &s, const ex &l);
97 // non-virtual functions in this class
99 /** Efficiently swap the contents of two expressions. */
100 void swap(ex & other) throw()
102 GINAC_ASSERT(bp->flags & status_flags::dynallocated);
103 GINAC_ASSERT(other.bp->flags & status_flags::dynallocated);
108 const_iterator begin() const throw();
109 const_iterator end() const throw();
110 const_preorder_iterator preorder_begin() const;
111 const_preorder_iterator preorder_end() const throw();
112 const_postorder_iterator postorder_begin() const;
113 const_postorder_iterator postorder_end() const throw();
116 ex eval(int level = 0) const { return bp->eval(level); }
117 ex evalf(int level = 0) const { return bp->evalf(level); }
118 ex evalm() const { return bp->evalm(); }
119 ex eval_ncmul(const exvector & v) const { return bp->eval_ncmul(v); }
122 void print(const print_context & c, unsigned level = 0) const;
123 void dbgprint() const;
124 void dbgprinttree() const;
127 bool info(unsigned inf) const { return bp->info(inf); }
130 size_t nops() const { return bp->nops(); }
131 ex op(size_t i) const { return bp->op(i); }
132 ex operator[](const ex & index) const { return (*bp)[index]; }
133 ex operator[](size_t i) const { return (*bp)[i]; }
134 ex & let_op(size_t i);
135 ex & operator[](const ex & index);
136 ex & operator[](size_t i);
140 // complex conjugation
141 ex conjugate() const { return bp->conjugate(); }
144 bool has(const ex & pattern) const { return bp->has(pattern); }
145 bool find(const ex & pattern, lst & found) const;
146 bool match(const ex & pattern) const;
147 bool match(const ex & pattern, lst & repl_lst) const { return bp->match(pattern, repl_lst); }
150 ex subs(const exmap & m, unsigned options = 0) const;
151 ex subs(const lst & ls, const lst & lr, unsigned options = 0) const;
152 ex subs(const ex & e, unsigned options = 0) const;
155 ex map(map_function & f) const { return bp->map(f); }
156 ex map(ex (*f)(const ex & e)) const;
158 // visitors and tree traversal
159 void accept(visitor & v) const { bp->accept(v); }
160 void traverse_preorder(visitor & v) const;
161 void traverse_postorder(visitor & v) const;
162 void traverse(visitor & v) const { traverse_preorder(v); }
165 int degree(const ex & s) const { return bp->degree(s); }
166 int ldegree(const ex & s) const { return bp->ldegree(s); }
167 ex coeff(const ex & s, int n = 1) const { return bp->coeff(s, n); }
168 ex lcoeff(const ex & s) const { return coeff(s, degree(s)); }
169 ex tcoeff(const ex & s) const { return coeff(s, ldegree(s)); }
172 ex expand(unsigned options=0) const;
173 ex collect(const ex & s, bool distributed = false) const { return bp->collect(s, distributed); }
175 // differentiation and series expansion
176 ex diff(const symbol & s, unsigned nth = 1) const;
177 ex series(const ex & r, int order, unsigned options = 0) const;
179 // rational functions
180 ex normal(int level = 0) const;
181 ex to_rational(exmap & repl) const;
182 ex to_rational(lst & repl_lst) const;
183 ex to_polynomial(exmap & repl) const;
184 ex to_polynomial(lst & repl_lst) const;
187 ex numer_denom() const;
189 // polynomial algorithms
190 ex unit(const ex &x) const;
191 ex content(const ex &x) const;
192 numeric integer_content() const;
193 ex primpart(const ex &x) const;
194 ex primpart(const ex &x, const ex &cont) const;
195 void unitcontprim(const ex &x, ex &u, ex &c, ex &p) const;
196 ex smod(const numeric &xi) const { return bp->smod(xi); }
197 numeric max_coefficient() const;
200 exvector get_free_indices() const { return bp->get_free_indices(); }
201 ex simplify_indexed(unsigned options = 0) const;
202 ex simplify_indexed(const scalar_products & sp, unsigned options = 0) const;
205 int compare(const ex & other) const;
206 bool is_equal(const ex & other) const;
207 bool is_zero() const { extern const ex _ex0; return is_equal(_ex0); }
210 ex symmetrize() const;
211 ex symmetrize(const lst & l) const;
212 ex antisymmetrize() const;
213 ex antisymmetrize(const lst & l) const;
214 ex symmetrize_cyclic() const;
215 ex symmetrize_cyclic(const lst & l) const;
218 unsigned return_type() const { return bp->return_type(); }
219 unsigned return_type_tinfo() const { return bp->return_type_tinfo(); }
221 unsigned gethash() const { return bp->gethash(); }
224 static ptr<basic> construct_from_basic(const basic & other);
225 static basic & construct_from_int(int i);
226 static basic & construct_from_uint(unsigned int i);
227 static basic & construct_from_long(long i);
228 static basic & construct_from_ulong(unsigned long i);
229 static basic & construct_from_double(double d);
230 static ptr<basic> construct_from_string_and_lst(const std::string &s, const ex &l);
231 void makewriteable();
232 void share(const ex & other) const;
234 #ifdef OBSCURE_CINT_HACK
236 static bool last_created_or_assigned_bp_can_be_converted_to_ex()
238 if (last_created_or_assigned_bp==0) return false;
239 if ((last_created_or_assigned_bp->flags &
240 status_flags::dynallocated)==0) return false;
241 if ((last_created_or_assigned_bp->flags &
242 status_flags::evaluated)==0) return false;
246 void update_last_created_or_assigned_bp()
248 last_created_or_assigned_bp = bp;
249 last_created_or_assigned_exp = (long)(void *)(this);
251 #endif // def OBSCURE_CINT_HACK
256 mutable ptr<basic> bp; ///< pointer to basic object managed by this
258 #ifdef OBSCURE_CINT_HACK
260 static ptr<basic> last_created_or_assigned_bp;
261 static basic * dummy_bp;
262 static long last_created_or_assigned_exp;
263 #endif // def OBSCURE_CINT_HACK
267 // performance-critical inlined method implementations
269 // This needs to be a basic* because we don't know that numeric is derived
270 // from basic and we need a basic& for the ex default constructor
271 extern const basic *_num0_bp;
274 ex::ex() throw() : bp(*const_cast<basic *>(_num0_bp))
276 GINAC_ASSERT(bp->flags & status_flags::dynallocated);
277 #ifdef OBSCURE_CINT_HACK
278 update_last_created_or_assigned_bp();
279 #endif // def OBSCURE_CINT_HACK
282 #ifdef OBSCURE_CINT_HACK
284 ex::ex(const ex & other) : bp(other.bp)
286 GINAC_ASSERT((bp->flags) & status_flags::dynallocated);
287 update_last_created_or_assigned_bp();
291 ex & ex::operator=(const ex & other)
293 GINAC_ASSERT(bp->flags & status_flags::dynallocated);
294 GINAC_ASSERT(other.bp->flags & status_flags::dynallocated);
296 update_last_created_or_assigned_bp();
299 #endif // def OBSCURE_CINT_HACK
302 ex::ex(const basic & other) : bp(construct_from_basic(other))
304 GINAC_ASSERT(bp->flags & status_flags::dynallocated);
305 #ifdef OBSCURE_CINT_HACK
306 update_last_created_or_assigned_bp();
307 #endif // def OBSCURE_CINT_HACK
311 ex::ex(int i) : bp(construct_from_int(i))
313 GINAC_ASSERT(bp->flags & status_flags::dynallocated);
314 #ifdef OBSCURE_CINT_HACK
315 update_last_created_or_assigned_bp();
316 #endif // def OBSCURE_CINT_HACK
320 ex::ex(unsigned int i) : bp(construct_from_uint(i))
322 GINAC_ASSERT(bp->flags & status_flags::dynallocated);
323 #ifdef OBSCURE_CINT_HACK
324 update_last_created_or_assigned_bp();
325 #endif // def OBSCURE_CINT_HACK
329 ex::ex(long i) : bp(construct_from_long(i))
331 GINAC_ASSERT(bp->flags & status_flags::dynallocated);
332 #ifdef OBSCURE_CINT_HACK
333 update_last_created_or_assigned_bp();
334 #endif // def OBSCURE_CINT_HACK
338 ex::ex(unsigned long i) : bp(construct_from_ulong(i))
340 GINAC_ASSERT(bp->flags & status_flags::dynallocated);
341 #ifdef OBSCURE_CINT_HACK
342 update_last_created_or_assigned_bp();
343 #endif // def OBSCURE_CINT_HACK
347 ex::ex(double const d) : bp(construct_from_double(d))
349 GINAC_ASSERT(bp->flags & status_flags::dynallocated);
350 #ifdef OBSCURE_CINT_HACK
351 update_last_created_or_assigned_bp();
352 #endif // def OBSCURE_CINT_HACK
356 ex::ex(const std::string &s, const ex &l) : bp(construct_from_string_and_lst(s, l))
358 GINAC_ASSERT(bp->flags & status_flags::dynallocated);
359 #ifdef OBSCURE_CINT_HACK
360 update_last_created_or_assigned_bp();
361 #endif // def OBSCURE_CINT_HACK
365 int ex::compare(const ex & other) const
367 #ifdef GINAC_COMPARE_STATISTICS
368 compare_statistics.total_compares++;
370 if (bp == other.bp) // trivial case: both expressions point to same basic
372 #ifdef GINAC_COMPARE_STATISTICS
373 compare_statistics.nontrivial_compares++;
375 const int cmpval = bp->compare(*other.bp);
378 // Expressions point to different, but equal, trees: conserve
379 // memory and make subsequent compare() operations faster by
380 // making both expressions point to the same tree.
388 bool ex::is_equal(const ex & other) const
390 #ifdef GINAC_COMPARE_STATISTICS
391 compare_statistics.total_is_equals++;
393 if (bp == other.bp) // trivial case: both expressions point to same basic
395 #ifdef GINAC_COMPARE_STATISTICS
396 compare_statistics.nontrivial_is_equals++;
398 const bool equal = bp->is_equal(*other.bp);
401 // Expressions point to different, but equal, trees: conserve
402 // memory and make subsequent compare() operations faster by
403 // making both expressions point to the same tree.
413 class const_iterator : public std::iterator<std::random_access_iterator_tag, ex, ptrdiff_t, const ex *, const ex &> {
415 friend class const_preorder_iterator;
416 friend class const_postorder_iterator;
419 const_iterator() throw() {}
422 const_iterator(const ex &e_, size_t i_) throw() : e(e_), i(i_) {}
425 // This should return an ex&, but that would be a reference to a
432 // This should return an ex*, but that would be a pointer to a
434 std::auto_ptr<ex> operator->() const
436 return std::auto_ptr<ex>(new ex(operator*()));
439 ex operator[](difference_type n) const
444 const_iterator &operator++() throw()
450 const_iterator operator++(int) throw()
452 const_iterator tmp = *this;
457 const_iterator &operator+=(difference_type n) throw()
463 const_iterator operator+(difference_type n) const throw()
465 return const_iterator(e, i + n);
468 inline friend const_iterator operator+(difference_type n, const const_iterator &it) throw()
470 return const_iterator(it.e, it.i + n);
473 const_iterator &operator--() throw()
479 const_iterator operator--(int) throw()
481 const_iterator tmp = *this;
486 const_iterator &operator-=(difference_type n) throw()
492 const_iterator operator-(difference_type n) const throw()
494 return const_iterator(e, i - n);
497 inline friend difference_type operator-(const const_iterator &lhs, const const_iterator &rhs) throw()
499 return lhs.i - rhs.i;
502 bool operator==(const const_iterator &other) const throw()
504 return are_ex_trivially_equal(e, other.e) && i == other.i;
507 bool operator!=(const const_iterator &other) const throw()
509 return !(*this == other);
512 bool operator<(const const_iterator &other) const throw()
517 bool operator>(const const_iterator &other) const throw()
519 return other < *this;
522 bool operator<=(const const_iterator &other) const throw()
524 return !(other < *this);
527 bool operator>=(const const_iterator &other) const throw()
529 return !(*this < other);
533 ex e; // this used to be a "const basic *", but in view of object fusion that wouldn't be safe
540 _iter_rep(const ex &e_, size_t i_, size_t i_end_) : e(e_), i(i_), i_end(i_end_) {}
542 bool operator==(const _iter_rep &other) const throw()
544 return are_ex_trivially_equal(e, other.e) && i == other.i;
547 bool operator!=(const _iter_rep &other) const throw()
549 return !(*this == other);
557 } // namespace internal
559 class const_preorder_iterator : public std::iterator<std::forward_iterator_tag, ex, ptrdiff_t, const ex *, const ex &> {
561 const_preorder_iterator() throw() {}
563 const_preorder_iterator(const ex &e, size_t n)
565 s.push(internal::_iter_rep(e, 0, n));
569 reference operator*() const
574 pointer operator->() const
579 const_preorder_iterator &operator++()
585 const_preorder_iterator operator++(int)
587 const_preorder_iterator tmp = *this;
592 bool operator==(const const_preorder_iterator &other) const throw()
597 bool operator!=(const const_preorder_iterator &other) const throw()
599 return !(*this == other);
603 std::stack<internal::_iter_rep, std::vector<internal::_iter_rep> > s;
607 while (!s.empty() && s.top().i == s.top().i_end) {
614 internal::_iter_rep & current = s.top();
616 if (current.i != current.i_end) {
617 const ex & child = current.e.op(current.i);
618 s.push(internal::_iter_rep(child, 0, child.nops()));
623 class const_postorder_iterator : public std::iterator<std::forward_iterator_tag, ex, ptrdiff_t, const ex *, const ex &> {
625 const_postorder_iterator() throw() {}
627 const_postorder_iterator(const ex &e, size_t n)
629 s.push(internal::_iter_rep(e, 0, n));
634 reference operator*() const
639 pointer operator->() const
644 const_postorder_iterator &operator++()
650 const_postorder_iterator operator++(int)
652 const_postorder_iterator tmp = *this;
657 bool operator==(const const_postorder_iterator &other) const throw()
662 bool operator!=(const const_postorder_iterator &other) const throw()
664 return !(*this == other);
668 std::stack<internal::_iter_rep, std::vector<internal::_iter_rep> > s;
672 while (s.top().i != s.top().i_end) {
673 internal::_iter_rep & current = s.top();
674 const ex & child = current.e.op(current.i);
675 s.push(internal::_iter_rep(child, 0, child.nops()));
681 if (s.top().i == s.top().i_end)
690 inline const_iterator ex::begin() const throw()
692 return const_iterator(*this, 0);
695 inline const_iterator ex::end() const throw()
697 return const_iterator(*this, nops());
700 inline const_preorder_iterator ex::preorder_begin() const
702 return const_preorder_iterator(*this, nops());
705 inline const_preorder_iterator ex::preorder_end() const throw()
707 return const_preorder_iterator();
710 inline const_postorder_iterator ex::postorder_begin() const
712 return const_postorder_iterator(*this, nops());
715 inline const_postorder_iterator ex::postorder_end() const throw()
717 return const_postorder_iterator();
723 /** Compare two objects of class quickly without doing a deep tree traversal.
724 * @return "true" if they are equal
725 * "false" if equality cannot be established quickly (e1 and e2 may
726 * still be equal, in this case. */
727 inline bool are_ex_trivially_equal(const ex &e1, const ex &e2)
729 return e1.bp == e2.bp;
732 /* Function objects for STL sort() etc. */
733 struct ex_is_less : public std::binary_function<ex, ex, bool> {
734 bool operator() (const ex &lh, const ex &rh) const { return lh.compare(rh) < 0; }
737 struct ex_is_equal : public std::binary_function<ex, ex, bool> {
738 bool operator() (const ex &lh, const ex &rh) const { return lh.is_equal(rh); }
741 struct op0_is_equal : public std::binary_function<ex, ex, bool> {
742 bool operator() (const ex &lh, const ex &rh) const { return lh.op(0).is_equal(rh.op(0)); }
745 struct ex_swap : public std::binary_function<ex, ex, void> {
746 void operator() (ex &lh, ex &rh) const { lh.swap(rh); }
749 // wrapper functions around member functions
750 inline size_t nops(const ex & thisex)
751 { return thisex.nops(); }
753 inline ex expand(const ex & thisex, unsigned options = 0)
754 { return thisex.expand(options); }
756 inline ex conjugate(const ex & thisex)
757 { return thisex.conjugate(); }
759 inline bool has(const ex & thisex, const ex & pattern)
760 { return thisex.has(pattern); }
762 inline bool find(const ex & thisex, const ex & pattern, lst & found)
763 { return thisex.find(pattern, found); }
765 inline int degree(const ex & thisex, const ex & s)
766 { return thisex.degree(s); }
768 inline int ldegree(const ex & thisex, const ex & s)
769 { return thisex.ldegree(s); }
771 inline ex coeff(const ex & thisex, const ex & s, int n=1)
772 { return thisex.coeff(s, n); }
774 inline ex numer(const ex & thisex)
775 { return thisex.numer(); }
777 inline ex denom(const ex & thisex)
778 { return thisex.denom(); }
780 inline ex numer_denom(const ex & thisex)
781 { return thisex.numer_denom(); }
783 inline ex normal(const ex & thisex, int level=0)
784 { return thisex.normal(level); }
786 inline ex to_rational(const ex & thisex, lst & repl_lst)
787 { return thisex.to_rational(repl_lst); }
789 inline ex to_rational(const ex & thisex, exmap & repl)
790 { return thisex.to_rational(repl); }
792 inline ex to_polynomial(const ex & thisex, exmap & repl)
793 { return thisex.to_polynomial(repl); }
795 inline ex to_polynomial(const ex & thisex, lst & repl_lst)
796 { return thisex.to_polynomial(repl_lst); }
798 inline ex collect(const ex & thisex, const ex & s, bool distributed = false)
799 { return thisex.collect(s, distributed); }
801 inline ex eval(const ex & thisex, int level = 0)
802 { return thisex.eval(level); }
804 inline ex evalf(const ex & thisex, int level = 0)
805 { return thisex.evalf(level); }
807 inline ex evalm(const ex & thisex)
808 { return thisex.evalm(); }
810 inline ex diff(const ex & thisex, const symbol & s, unsigned nth = 1)
811 { return thisex.diff(s, nth); }
813 inline ex series(const ex & thisex, const ex & r, int order, unsigned options = 0)
814 { return thisex.series(r, order, options); }
816 inline bool match(const ex & thisex, const ex & pattern, lst & repl_lst)
817 { return thisex.match(pattern, repl_lst); }
819 inline ex simplify_indexed(const ex & thisex, unsigned options = 0)
820 { return thisex.simplify_indexed(options); }
822 inline ex simplify_indexed(const ex & thisex, const scalar_products & sp, unsigned options = 0)
823 { return thisex.simplify_indexed(sp, options); }
825 inline ex symmetrize(const ex & thisex)
826 { return thisex.symmetrize(); }
828 inline ex symmetrize(const ex & thisex, const lst & l)
829 { return thisex.symmetrize(l); }
831 inline ex antisymmetrize(const ex & thisex)
832 { return thisex.antisymmetrize(); }
834 inline ex antisymmetrize(const ex & thisex, const lst & l)
835 { return thisex.antisymmetrize(l); }
837 inline ex symmetrize_cyclic(const ex & thisex)
838 { return thisex.symmetrize_cyclic(); }
840 inline ex symmetrize_cyclic(const ex & thisex, const lst & l)
841 { return thisex.symmetrize_cyclic(l); }
843 inline ex op(const ex & thisex, size_t i)
844 { return thisex.op(i); }
846 inline ex lhs(const ex & thisex)
847 { return thisex.lhs(); }
849 inline ex rhs(const ex & thisex)
850 { return thisex.rhs(); }
852 inline bool is_zero(const ex & thisex)
853 { return thisex.is_zero(); }
855 inline void swap(ex & e1, ex & e2)
858 inline ex ex::subs(const exmap & m, unsigned options) const
860 return bp->subs(m, options);
863 inline ex subs(const ex & thisex, const exmap & m, unsigned options = 0)
864 { return thisex.subs(m, options); }
866 inline ex subs(const ex & thisex, const lst & ls, const lst & lr, unsigned options = 0)
867 { return thisex.subs(ls, lr, options); }
869 inline ex subs(const ex & thisex, const ex & e, unsigned options = 0)
870 { return thisex.subs(e, options); }
873 /* Convert function pointer to function object suitable for map(). */
874 class pointer_to_map_function : public map_function {
876 ex (*ptr)(const ex &);
878 explicit pointer_to_map_function(ex x(const ex &)) : ptr(x) {}
879 ex operator()(const ex & e) { return ptr(e); }
883 class pointer_to_map_function_1arg : public map_function {
885 ex (*ptr)(const ex &, T1);
888 explicit pointer_to_map_function_1arg(ex x(const ex &, T1), T1 a1) : ptr(x), arg1(a1) {}
889 ex operator()(const ex & e) { return ptr(e, arg1); }
892 template<class T1, class T2>
893 class pointer_to_map_function_2args : public map_function {
895 ex (*ptr)(const ex &, T1, T2);
899 explicit pointer_to_map_function_2args(ex x(const ex &, T1, T2), T1 a1, T2 a2) : ptr(x), arg1(a1), arg2(a2) {}
900 ex operator()(const ex & e) { return ptr(e, arg1, arg2); }
903 template<class T1, class T2, class T3>
904 class pointer_to_map_function_3args : public map_function {
906 ex (*ptr)(const ex &, T1, T2, T3);
911 explicit pointer_to_map_function_3args(ex x(const ex &, T1, T2, T3), T1 a1, T2 a2, T3 a3) : ptr(x), arg1(a1), arg2(a2), arg3(a3) {}
912 ex operator()(const ex & e) { return ptr(e, arg1, arg2, arg3); }
915 inline ex ex::map(ex f(const ex &)) const
917 pointer_to_map_function fcn(f);
921 // convenience type checker template functions
923 /** Check if ex is a handle to a T, including base classes. */
925 inline bool is_a(const ex &obj)
927 return is_a<T>(*obj.bp);
930 /** Check if ex is a handle to a T, not including base classes. */
932 inline bool is_exactly_a(const ex &obj)
934 return is_exactly_a<T>(*obj.bp);
937 /** Return a reference to the basic-derived class T object embedded in an
938 * expression. This is fast but unsafe: the result is undefined if the
939 * expression does not contain a T object at its top level. Hence, you
940 * should generally check the type of e first. Also, you shouldn't cache
941 * the returned reference because GiNaC's garbage collector may destroy
942 * the referenced object any time it's used in another expression.
944 * @param e expression
945 * @return reference to object of class T
946 * @see is_exactly_a<class T>() */
948 inline const T &ex_to(const ex &e)
950 GINAC_ASSERT(is_a<T>(e));
951 return static_cast<const T &>(*e.bp);
957 // Specializations of Standard Library algorithms
960 /** Specialization of std::swap() for ex objects. */
962 inline void swap(GiNaC::ex &a, GiNaC::ex &b)
967 /** Specialization of std::iter_swap() for vector<ex> iterators. */
969 inline void iter_swap(vector<GiNaC::ex>::iterator i1, vector<GiNaC::ex>::iterator i2)
974 /** Specialization of std::iter_swap() for list<ex> iterators. */
976 inline void iter_swap(list<GiNaC::ex>::iterator i1, list<GiNaC::ex>::iterator i2)
983 #endif // ndef __GINAC_EX_H__