- ex_to<foo>(obj) is a good candidate for asserting is_a<foo>(obj).

diff --git a/ginac/basic.h b/ginac/basic.h
index 77134bd612ca568fffec2438e50c2163da1af8cf..b319e0d5455c12f3092438ed676b5fe0cbeb5361 100644 (file)
--- a/ginac/basic.h
+++ b/ginac/basic.h
@@ -217,6 +217,7 @@ inline bool is_exactly_a(const ex & obj)
 template <class T>
 inline const T &ex_to(const ex &e)
 {
+       GINAC_ASSERT(is_a<T>(e));
        return static_cast<const T &>(*e.bp);
 }