*
* Interface to relations between expressions. */
-#ifndef _RELATIONAL_H_
-#define _RELATIONAL_H_
+/*
+ * GiNaC Copyright (C) 1999-2005 Johannes Gutenberg University Mainz, Germany
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
-class relational;
+#ifndef __GINAC_RELATIONAL_H__
+#define __GINAC_RELATIONAL_H__
#include "basic.h"
+#include "ex.h"
+
+namespace GiNaC {
/** This class holds a relation consisting of two expressions and a logical
* relation between them. */
class relational : public basic
{
+ GINAC_DECLARE_REGISTERED_CLASS(relational, basic)
// types
public:
- enum operators { equal,
- not_equal,
- less,
- less_or_equal,
- greater,
- greater_or_equal
- };
-
-// member functions
-
- // default constructor, destructor, copy constructor assignment operator and helpers
+ enum operators {
+ equal,
+ not_equal,
+ less,
+ less_or_equal,
+ greater,
+ greater_or_equal
+ };
+
+ // other constructors
public:
- relational();
- ~relational();
- relational(relational const & other);
- relational const & operator=(relational const & other);
+ relational(const ex & lhs, const ex & rhs, operators oper=equal);
+
+ // functions overriding virtual functions from base classes
+public:
+ unsigned precedence() const {return 20;}
+ bool info(unsigned inf) const;
+ size_t nops() const;
+ ex op(size_t i) const;
+ ex map(map_function & f) const;
+ ex subs(const exmap & m, unsigned options = 0) const;
+ ex eval(int level=0) const;
+
protected:
- void copy(relational const & other);
- void destroy(bool call_parent);
+ ex eval_ncmul(const exvector & v) const;
+ bool match_same_type(const basic & other) const;
+ unsigned return_type() const;
+ unsigned return_type_tinfo() const;
+ unsigned calchash() const;
- // other constructors
-public:
- relational(ex const & lhs, ex const & rhs, operators oper=equal);
-
- // functions overriding virtual functions from bases classes
-public:
- basic * duplicate() const;
- void printraw(ostream & os) const;
- void print(ostream & os, unsigned upper_precedence=0) const;
- void printcsrc(ostream & os, unsigned type, unsigned upper_precedence=0) const;
- bool info(unsigned inf) const;
- int nops() const;
- ex & let_op(int const i);
- ex eval(int level=0) const;
- ex evalf(int level=0) const;
- ex simplify_ncmul(exvector const & v) const;
+ // new virtual functions which can be overridden by derived classes
protected:
- int compare_same_type(basic const & other) const;
- unsigned return_type(void) const;
- unsigned return_type_tinfo(void) const;
+ void do_print(const print_context & c, unsigned level) const;
+ void do_print_python_repr(const print_python_repr & c, unsigned level) const;
- // new virtual functions which can be overridden by derived classes
- // none
+public:
+ virtual ex lhs() const;
+ virtual ex rhs() const;
+
+ // non-virtual functions in this class
+private:
+ // For conversions to boolean, as would be used in an if conditional,
+ // implicit conversions from bool to int have a large number of
+ // undesirable side effects. The following safe_bool type enables
+ // use of relational objects in conditionals without those side effects
+ struct safe_bool_helper {
+ void nonnull() {};
+ };
+
+ typedef void (safe_bool_helper::*safe_bool)();
+
+ safe_bool make_safe_bool(bool) const;
- // non-virtual functions in this class
public:
- operator bool(void) const;
-
+ operator safe_bool() const;
+ safe_bool operator!() const;
+
// member variables
-
+
protected:
- ex lh;
- ex rh;
- operators o;
- static unsigned precedence;
+ ex lh;
+ ex rh;
+ operators o;
};
-// global constants
+// utility functions
-extern const relational some_relational;
-extern type_info const & typeid_relational;
-
-#define ex_to_relational(X) static_cast<relational const &>(*(X).bp)
+/** Specialization of is_exactly_a<relational>(obj) for relational objects. */
+template<> inline bool is_exactly_a<relational>(const basic & obj)
+{
+ return obj.tinfo()==TINFO_relational;
+}
-#endif // ndef _RELATIONAL_H_
+// inlined functions for efficiency
+inline relational::safe_bool relational::operator!() const
+{
+ return make_safe_bool(!static_cast<bool>(*this));
+}
+} // namespace GiNaC
+#endif // ndef __GINAC_RELATIONAL_H__