3 * Interface to GiNaC's constant types and some special constants. */
6 * GiNaC Copyright (C) 1999-2002 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_CONSTANT_H__
24 #define __GINAC_CONSTANT_H__
32 typedef ex (*evalffunctype)(void);
34 /** This class holds constants, symbols with specific numerical value. Each
35 * object of this class must either provide their own function to evaluate it
36 * to class numeric or provide the constant as a numeric (if it's an exact
38 class constant : public basic
40 GINAC_DECLARE_REGISTERED_CLASS(constant, basic)
46 constant(const std::string & initname, evalffunctype efun = 0, const std::string & texname = std::string());
47 constant(const std::string & initname, const numeric & initnumber, const std::string & texname = std::string());
49 // functions overriding virtual functions from base classes
51 void print(const print_context & c, unsigned level = 0) const;
52 ex evalf(int level = 0) const;
54 ex derivative(const symbol & s) const;
55 bool is_equal_same_type(const basic & other) const;
56 unsigned calchash(void) const;
58 // new virtual functions which can be overridden by derived classes
61 // non-virtual functions in this class
67 std::string name; ///< printname of this constant
68 std::string TeX_name; ///< LaTeX name
70 numeric *number; ///< numerical value this constant evalf()s to
71 unsigned serial; ///< unique serial number for comparison
72 static unsigned next_serial;
75 extern const constant Pi;
76 extern const constant Catalan;
77 extern const constant Euler;
81 /** Specialization of is_exactly_a<constant>(obj) for constant objects. */
82 template<> inline bool is_exactly_a<constant>(const basic & obj)
84 return obj.tinfo()==TINFO_constant;
89 #endif // ndef __GINAC_CONSTANT_H__