gras: make ptree usage optional on old boosts

1 files changed, 10 insertions, 0 deletions

diff --git a/lib/top_block_query_no_ptree.cpp b/lib/top_block_query_no_ptree.cpp
new file mode 100644
index 0000000..0ec6dd5
--- /dev/null
+++ b/lib/top_block_query_no_ptree.cpp
@@ -0,0 +1,10 @@
+// Copyright (C) by Josh Blum. See LICENSE.txt for licensing information.
+
+#include "element_impl.hpp"
+
+using namespace gras;
+
+std::string TopBlock::query(const std::string &)
+{
+    return "";
+}