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[ginac.git] / ginac / expair.h

diff --git a/ginac/expair.h b/ginac/expair.h
index 954442509e40a52cc1f7f370c977368db6e28a79..ce17c8df51e1d3661dcdf3f94962a1526fbe428f 100644 (file)
--- a/ginac/expair.h
+++ b/ginac/expair.h
@@ -3,7 +3,7 @@
  *  Definition of expression pairs (building blocks of expairseq). */
 
 /*
- *  GiNaC Copyright (C) 1999-2002 Johannes Gutenberg University Mainz, Germany
+ *  GiNaC Copyright (C) 1999-2004 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
@@ -38,20 +38,7 @@ class expair
 {
 public:
        expair() : rest(0), coeff(1) { }
-       ~expair() { }
-       expair(const expair & other) : rest(other.rest), coeff(other.coeff)
-       {
-               GINAC_ASSERT(is_exactly_a<numeric>(coeff));
-       }
-       const expair & operator=(const expair & other)
-       {
-               if (this != &other) {
-                       rest = other.rest;
-                       coeff = other.coeff;
-               }
-               return *this;
-       }
-       
+
        /** Construct an expair from two ex. */
        expair(const ex & r, const ex & c) : rest(r), coeff(c)
        {
@@ -85,7 +72,7 @@ public:
        void print(std::ostream & os) const;
        
        /** True if this is of the form (numeric,ex(1)). */
-       bool is_canonical_numeric(void) const
+       bool is_canonical_numeric() const
        {
                GINAC_ASSERT(is_exactly_a<numeric>(coeff));
                return (is_exactly_a<numeric>(rest) && (coeff.is_equal(1)));
@@ -97,20 +84,37 @@ public:
                rest.swap(other.rest);
                coeff.swap(other.coeff);
        }
-       
+
+       const expair conjugate() const;
+
        ex rest;    ///< first member of pair, an arbitrary expression
        ex coeff;   ///< second member of pair, must be numeric
 };
 
-/** Function objects for insertion into third argument of STL's sort() etc. */
+/** Function object for insertion into third argument of STL's sort() etc. */
 struct expair_is_less : public std::binary_function<expair, expair, bool> {
        bool operator()(const expair &lh, const expair &rh) const { return lh.is_less(rh); }
 };
 
+/** Function object not caring about the numerical coefficients for insertion
+ *  into third argument of STL's sort().  Note that this does not define a
+ *  strict weak ordering since for any symbol x we have neither 3*x<2*x or
+ *  2*x<3*x.  Handle with care! */
+struct expair_rest_is_less : public std::binary_function<expair, expair, bool> {
+       bool operator()(const expair &lh, const expair &rh) const { return (lh.rest.compare(rh.rest)<0); }
+};
+
 struct expair_swap : public std::binary_function<expair, expair, void> {
        void operator()(expair &lh, expair &rh) const { lh.swap(rh); }
 };
 
+inline void swap(expair & e1, expair & e2)
+{ e1.swap(e2); }
+
+// This makes STL algorithms use the more efficient swap operation for ex objects
+inline void iter_swap(std::vector<expair>::iterator i1, std::vector<expair>::iterator i2)
+{ i1->swap(*i2); }
+
 } // namespace GiNaC
 
 #endif // ndef __GINAC_EXPAIR_H__