Fix crash when using empty list in sym/asym (issues/129)

kpeeters · kpeeters · commit 7c7b02e5f397 · 2019-02-09T22:01:58.000Z
diff --git a/core/algorithms/sym.cc b/core/algorithms/sym.cc
@@ -8,6 +8,8 @@ using namespace cadabra;
 sym::sym(const Kernel& k, Ex& tr, Ex& objs, bool s)
 	: Algorithm(k, tr), objects(objs), sign(s)
 	{
+	if(objects.size()==0)
+		throw ArgumentException("sym/asym: need a list of objects over which to (anti)symmetrise.");
 	}
 
 bool sym::can_apply(iterator it)

Original file line number	Diff line number	Diff line change
`@@ -8,6 +8,8 @@ using namespace cadabra;`
`8`	`8`	`sym::sym(const Kernel& k, Ex& tr, Ex& objs, bool s)`
`9`	`9`	`: Algorithm(k, tr), objects(objs), sign(s)`
`10`	`10`	`{`
	`11`	`+ if(objects.size()==0)`
	`12`	`+ throw ArgumentException("sym/asym: need a list of objects over which to (anti)symmetrise.");`
`11`	`13`	`}`
`12`	`14`
`13`	`15`	`bool sym::can_apply(iterator it)`