7 basic() : refcount(0) {}
15 void construct_from_basic(const basic &);
18 ex basic::eval() const {
22 inline ex::ex(const basic &b) { construct_from_basic (b); }
23 inline ex::~ex() { if (--bp->refcount == 0) delete bp; }
24 void ex::construct_from_basic(const basic &b) {
25 const ex & tmpex = b.eval();
30 ex pow() { return basic(); }
34 try { pow (); } catch (int) {}