X-Git-Url: https://ginac.de/ginac.git//ginac.git?a=blobdiff_plain;f=ginac%2Frelational.h;h=c8044f581bdd9728a17e4aec4e83671cf6670aa8;hb=dcc848e23e4d793b2b1095012a8951f5245a68d5;hp=fb1111580a4afb085a12ea9017aedfc98345e18e;hpb=d448856f20cb58f939ddbf636e7f72e3599b1468;p=ginac.git

diff --git a/ginac/relational.h b/ginac/relational.h
index fb111158..c8044f58 100644
--- a/ginac/relational.h
+++ b/ginac/relational.h
@@ -3,7 +3,7 @@
  *  Interface to relations between expressions. */
 
 /*
- *  GiNaC Copyright (C) 1999-2001 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
@@ -54,15 +54,17 @@ public:
 	void print(const print_context & c, unsigned level = 0) const;
 	unsigned precedence(void) 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 eval(int level=0) 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;
 
 	// new virtual functions which can be overridden by derived classes
 public:
@@ -70,9 +72,23 @@ public:
 	virtual ex rhs(void) 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(void) const;
+	safe_bool operator!(void) const;
+
 // member variables
 	
 protected:
@@ -89,6 +105,12 @@ 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__