sequential_elem operator should be const.
@@ -15,7 +15,7 @@ class MatchCandidate;
template <typename _Elem>
struct sequential_elem
{
- inline bool operator()(_Elem m1, _Elem m2)
+ inline bool operator()(_Elem m1, _Elem m2) const
{
return m1->starttoken() < m2->starttoken();
}
