Cleanup warnings

Author: flexferrum

src/expression_evaluator.cpp

@@ -281,7 +281,7 @@ Value CallExpression::CallGlobalRange(RenderContext& values)
             size_t count = static_cast<size_t>(m_stop - m_start);
             return static_cast<size_t>(count / m_step);
         }
-        Value GetValueByIndex(int64_t idx) const
+        Value GetValueByIndex(int64_t idx) const override
         {
             return m_start + m_step * idx;
         }

src/value.cpp

@@ -113,7 +113,7 @@ struct SubscriptionVisitor : public boost::static_visitor<Value>
         if (index < 0 || static_cast<size_t>(index) >= values.size())
             return Value();
 
-        return values[index];
+        return values[static_cast<size_t>(index)];
     }
 
     Value operator() (const GenericList& values, const int64_t index) const