* Definition of expression pairs (building blocks of expairseq). */
/*
- * 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
{
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)
{
return coeff.compare(other.coeff);
}
- void print(std::ostream & os) const
- {
- os << "expair:";
- print_tree c(os);
- rest.print(c, c.delta_indent);
- coeff.print(c, c.delta_indent);
- }
+ 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_ex_exactly_of_type(rest,numeric) &&
- (coeff.is_equal(1)));
+ return (is_exactly_a<numeric>(rest) && (coeff.is_equal(1)));
+ }
+
+ /** Swap contents with other expair. */
+ void swap(expair & other)
+ {
+ rest.swap(other.rest);
+ coeff.swap(other.coeff);
}
ex rest; ///< first member of pair, an arbitrary expression
};
/** Function object for insertion into third argument of STL's sort() etc. */
-class expair_is_less
-{
-public:
- bool operator()(const expair &lh, const expair &rh) const
- {
- return lh.is_less(rh);
- }
+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__