// non-virtual functions in this class
public:
- void swap(ex & other);
+ /** Efficiently swap the contents of two expressions. */
+ void swap(ex & other)
+ {
+ GINAC_ASSERT(bp!=0);
+ GINAC_ASSERT(bp->flags & status_flags::dynallocated);
+ GINAC_ASSERT(other.bp!=0);
+ GINAC_ASSERT(other.bp->flags & status_flags::dynallocated);
+
+ basic * tmpbp = bp;
+ bp = other.bp;
+ other.bp = tmpbp;
+ }
+
void print(const print_context & c, unsigned level = 0) const;
void printtree(std::ostream & os) const;
void dbgprint(void) const;
inline void swap(ex & e1, ex & e2)
{ e1.swap(e2); }
+// This makes STL algorithms use the more efficient swap operation for ex objects
+inline void iter_swap(std::vector<ex>::iterator i1, std::vector<ex>::iterator i2)
+{ i1->swap(*i2); }
+
/* Function objects for STL sort() etc. */
struct ex_is_less : public std::binary_function<ex, ex, bool> {