some sections where sums/products are constructed are slightly more efficient

[ginac.git] / ginac / expair.h

diff --git a/ginac/expair.h b/ginac/expair.h
index 91dd2323ffb2352bdaf0240acd2af9c150f7420e..a285295899223a9268628cf639d9551ca01e238e 100644 (file)
--- a/ginac/expair.h
+++ b/ginac/expair.h
@@ -97,19 +97,25 @@ public:
                return (is_ex_exactly_of_type(rest,numeric) &&
                        (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
        ex coeff;   ///< second member of pair, must be numeric
 };
 
-/** 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);
-       }
+/** Function objects 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); }
+};
+
+struct expair_swap : public std::binary_function<expair, expair, void> {
+       void operator()(expair &lh, expair &rh) const { lh.swap(rh); }
 };
 
 } // namespace GiNaC