* All operators are now strictly following the semantics we all know from

[ginac.git] / ginac / ex.h

diff --git a/ginac/ex.h b/ginac/ex.h
index 8ade899b06136f1479a982834547fae35503a3ba..7b36eff864bc061ee4e86e1efb0c3c48d0139f37 100644 (file)
--- a/ginac/ex.h
+++ b/ginac/ex.h
@@ -52,7 +52,7 @@ public:
        ex();
        ~ex();
        ex(const ex & other);
-       const ex & operator=(const ex & other);
+       ex & operator=(const ex & other);
        // other ctors
 public:
        ex(const basic & other);
@@ -124,9 +124,6 @@ public:
        unsigned return_type(void) const { return bp->return_type(); }
        unsigned return_type_tinfo(void) const { return bp->return_type_tinfo(); }
        unsigned gethash(void) const { return bp->gethash(); }
-       
-       ex exadd(const ex & rh) const;
-       ex exmul(const ex & rh) const;
 private:
        void construct_from_basic(const basic & other);
        void construct_from_int(int i);
@@ -212,16 +209,17 @@ ex::ex(const ex & other) : bp(other.bp)
 }
 
 inline
-const ex & ex::operator=(const ex & other)
+ex & ex::operator=(const ex & other)
 {
        /*debugmsg("ex operator=",LOGLEVEL_ASSIGNMENT);*/
        GINAC_ASSERT(bp!=0);
        GINAC_ASSERT(bp->flags & status_flags::dynallocated);
        GINAC_ASSERT(other.bp!=0);
        GINAC_ASSERT(other.bp->flags & status_flags::dynallocated);
+       // NB: must first increment other.bp->refcount, since other might be *this.
+       ++other.bp->refcount;
        if (--bp->refcount==0)
                delete bp;
-       ++other.bp->refcount;
        bp = other.bp;
 #ifdef OBSCURE_CINT_HACK
        update_last_created_or_assigned_bp();