X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=blobdiff_plain;f=ginac%2Frelational.h;h=cbe51468eeb9691199a10c79d59a4bb41c8986cd;hp=779b1fe871e46ef1b8985fa2c4a934627a5fa1f1;hb=1ed8f877ea0ca066c276d5bea08f2e775559aa81;hpb=759fd0ecbd27c082d89d69a5f77a71eef046f96a

diff --git a/ginac/relational.h b/ginac/relational.h
index 779b1fe8..cbe51468 100644
--- a/ginac/relational.h
+++ b/ginac/relational.h
@@ -3,7 +3,7 @@
  *  Interface to relations between expressions. */
 
 /*
- *  GiNaC Copyright (C) 1999-2002 Johannes Gutenberg University Mainz, Germany
+ *  GiNaC Copyright (C) 1999-2003 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
@@ -45,36 +45,51 @@ public:
 		greater_or_equal
 	};
 	
-	// other ctors
+	// other constructors
 public:
 	relational(const ex & lhs, const ex & rhs, operators oper=equal);
 	
 	// functions overriding virtual functions from base classes
 public:
 	void print(const print_context & c, unsigned level = 0) const;
-	unsigned precedence(void) const {return 20;}
+	unsigned precedence() const {return 20;}
 	bool info(unsigned inf) const;
-	unsigned nops() const;
-	ex & let_op(int i);
+	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;
-	ex subs(const lst & ls, const lst & lr, bool no_pattern = false) const;
-	ex simplify_ncmul(const exvector & v) const;
 
 protected:
+	ex eval_ncmul(const exvector & v) const;
 	bool match_same_type(const basic & other) const;
-	unsigned return_type(void) const;
-	unsigned return_type_tinfo(void) const;
-	unsigned calchash(void) const;
+	unsigned return_type() const;
+	unsigned return_type_tinfo() const;
+	unsigned calchash() const;
 
 	// new virtual functions which can be overridden by derived classes
 public:
-	virtual ex lhs(void) const;
-	virtual ex rhs(void) const;
+	virtual ex lhs() const;
+	virtual ex rhs() const;
 
 	// non-virtual functions in this class
-public:
-	operator bool(void) const;
+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;
+
+public:
+	operator safe_bool() const;
+	safe_bool operator!() const;
+
 // member variables
 	
 protected:
@@ -91,6 +106,12 @@ template<> inline bool is_exactly_a<relational>(const basic & obj)
 	return obj.tinfo()==TINFO_relational;
 }
 
+// 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__