X-Git-Url: https://ginac.de/ginac.git//ginac.git?a=blobdiff_plain;f=ginac%2Fexpair.h;h=513dd5c96442b294f1d4a2a755196155a8459334;hb=eb36a2fcd5f2c121a249f6d54bd18b2138bf6c3c;hp=954442509e40a52cc1f7f370c977368db6e28a79;hpb=e7cc6a764ff67b5885d6633385fac23ccc1dc9a7;p=ginac.git

diff --git a/ginac/expair.h b/ginac/expair.h
index 95444250..513dd5c9 100644
--- a/ginac/expair.h
+++ b/ginac/expair.h
@@ -102,15 +102,30 @@ public:
 	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__