Remove std::reference_wrapper around tiledb::Context (#340)

Author: jparismorgan

src/include/detail/linalg/tdb_matrix.h

@@ -80,7 +80,7 @@ class tdbBlockedMatrix : public MatrixBase {
 
   log_timer constructor_timer{"tdbBlockedMatrix constructor"};
 
-  std::reference_wrapper<const tiledb::Context> ctx_;
+  tiledb::Context ctx_;
   std::string uri_;
   std::unique_ptr<tiledb::Array> array_;
   tiledb::ArraySchema schema_;

src/include/detail/linalg/tdb_partitioned_matrix.h

@@ -134,8 +134,7 @@ class tdbPartitionedMatrix
   // We don't actually use this
   // size_t num_array_cols_{0};
 
-  std::reference_wrapper<const tiledb::Context> ctx_;
-  // tiledb::Context ctx_;
+  tiledb::Context ctx_;
 
   std::string partitioned_vectors_uri_;
   std::unique_ptr<tiledb::Array> partitioned_vectors_array_;

src/include/index/index_group.h

@@ -93,7 +93,7 @@ class base_index_group {
   friend IndexGroup;
 
  protected:
-  std::reference_wrapper<const tiledb::Context> cached_ctx_;
+  tiledb::Context cached_ctx_;
   std::string group_uri_;
   size_t index_timestamp_{0};
   size_t group_timestamp_{0};