X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=blobdiff_plain;f=ginac%2Fex.h;h=d16bdbc1998c5b31de414f232b42c8e675baa97a;hp=b9360416018296a349b967b2c1c130e24ec793f9;hb=757406e244f4f257aafaa0f355d5376122cea10e;hpb=201fc92bfd5806596a5a75a5ae0586d7302c0897

diff --git a/ginac/ex.h b/ginac/ex.h
index b9360416..d16bdbc1 100644
--- a/ginac/ex.h
+++ b/ginac/ex.h
@@ -555,6 +555,36 @@ inline ex ex::map(ex f(const ex &)) const
 	return bp->map(fcn);
 }
 
+// convenience type checker template functions
+
+/** Check if ex is a handle to a T, including base classes. */
+template <class T>
+inline bool is_a(const ex &obj)
+{
+	return is_a<T>(*obj.bp);
+}
+
+/** Check if ex is a handle to a T, not including base classes. */
+template <class T>
+inline bool is_exactly_a(const ex &obj)
+{
+	return is_exactly_a<T>(*obj.bp);
+}
+
+/** Return a reference to the basic-derived class T object embedded in an
+ *  expression.  This is fast but unsafe: the result is undefined if the
+ *  expression does not contain a T object at its top level.  Hence, you
+ *  should generally check the type of e first.
+ *
+ *  @param e expression
+ *  @return reference to object of class T
+ *  @see is_exactly_a<class T>() */
+template <class T>
+inline const T &ex_to(const ex &e)
+{
+	GINAC_ASSERT(is_a<T>(e));
+	return static_cast<const T &>(*e.bp);
+}
 
 } // namespace GiNaC