1 files changed, 12 insertions, 2 deletions
diff --git a/src/libstore/path-with-outputs.hh b/src/libstore/path-with-outputs.hh
index e4235d197..0cb5eb223 100644
--- a/src/libstore/path-with-outputs.hh
+++ b/src/libstore/path-with-outputs.hh
@@ -4,6 +4,7 @@
 
 #include "path.hh"
 #include "derived-path.hh"
+#include "nlohmann/json_fwd.hpp"
 
 namespace nix {
 
@@ -34,9 +35,13 @@ StorePathWithOutputs followLinksToStorePathWithOutputs(const Store & store, std:
 
 typedef std::set<std::string> OutputNames;
 
-struct AllOutputs { };
+struct AllOutputs {
+    bool operator < (const AllOutputs & _) const { return false; }
+};
 
-struct DefaultOutputs { };
+struct DefaultOutputs {
+    bool operator < (const DefaultOutputs & _) const { return false; }
+};
 
 typedef std::variant<DefaultOutputs, AllOutputs, OutputNames> OutputsSpec;
 
@@ -44,4 +49,9 @@ typedef std::variant<DefaultOutputs, AllOutputs, OutputNames> OutputsSpec;
    'prefix^*', returning the prefix and the outputs spec. */
 std::pair<std::string, OutputsSpec> parseOutputsSpec(const std::string & s);
 
+std::string printOutputsSpec(const OutputsSpec & outputsSpec);
+
+void to_json(nlohmann::json &, const OutputsSpec &);
+void from_json(const nlohmann::json &, OutputsSpec &);
+
 }