Fixed BitVector::full() for BitVectors with size 0

src/storm/storage/BitVector.cpp

@@ -566,6 +566,9 @@ namespace storm {
         }
 
         bool BitVector::full() const {
+            if (bitCount == 0) {
+                return true;
+            }
             // Check that all buckets except the last one have all bits set.
             uint64_t* last = buckets + bucketCount() - 1;
             for (uint64_t const* it = buckets; it < last; ++it) {

src/storm/storage/BitVector.h

@@ -417,6 +417,7 @@ namespace storm {
             
             /*!
              * Retrievs whether all bits are set in this bit vector.
+             * If the bit vector has size 0, this method always returns true.
              *
              * @return True iff all bits in the bit vector are set.
              */