fix typo, fix bug in FlagCollection, and silence a compiler warning (#…

…925)

Co-authored-by: Luke Roberts <lfroberts@lanl.gov>

src/interface/metadata.hpp

@@ -230,7 +230,9 @@ class Metadata {
     FlagCollection(MetadataFlag first, Args... args)
         : FlagCollection({first, std::forward<Args>(args)...}, false) {}
     // Check if set empty
-    bool Empty() const { return (unions_.empty() && intersections_.empty()); }
+    bool Empty() const {
+      return (unions_.empty() && intersections_.empty() && exclusions_.empty());
+    }
     // Union
     template <template <class...> class Container_t, class... extra>
     void TakeUnion(const Container_t<MetadataFlag, extra...> &flags) {

src/interface/sparse_pack_base.hpp

@@ -193,6 +193,8 @@ struct PackDescriptor {
         var_group_names.push_back(std::to_string(vg));
       return var_group_names;
     }
+    // silence compiler warnings about no return statement
+    return std::vector<std::string>();
   }
 };
 } // namespace impl

src/mesh/mesh.hpp

@@ -211,7 +211,7 @@ class Mesh {
 
   // expose a mesh-level call to get lists of variables from resolved_packages
   template <typename... Args>
-  std::vector<std::string> GetVariablesNames(Args &&...args) {
+  std::vector<std::string> GetVariableNames(Args &&...args) {
     return resolved_packages->GetVariableNames(std::forward<Args>(args)...);
   }