Allow custom sorting function for JSON serializer

[folly.git] / folly / json.h

diff --git a/folly/json.h b/folly/json.h
index 87a907886a3305512465494b9b0c1388d020ed19..788587a8aa6defbabf2b8ef69b91f07f5ceee278 100644 (file)
--- a/folly/json.h
+++ b/folly/json.h
@@ -43,8 +43,9 @@
 #include <iosfwd>
 #include <string>
 
-#include <folly/dynamic.h>
+#include <folly/Function.h>
 #include <folly/Range.h>
+#include <folly/dynamic.h>
 
 namespace folly {
 
@@ -95,8 +96,14 @@ namespace json {
     bool allow_trailing_comma;
 
     // Sort keys of all objects before printing out (potentially slow)
+    // using dynamic::operator<.
+    // Has no effect if sort_keys_by is set.
     bool sort_keys;
 
+    // Sort keys of all objects before printing out (potentially slow)
+    // using the provided less functor.
+    Function<bool(dynamic const&, dynamic const&) const> sort_keys_by;
+
     // Replace invalid utf8 characters with U+FFFD and continue
     bool skip_invalid_utf8;