time support: check and define NDN_CPP_HAVE_GMTIME_SUPPORT. In ndn_toIsoString and ndn_fromIsoString, return an error if not supported.
diff --git a/ndn-cpp/c/errors.c b/ndn-cpp/c/errors.c
index 55ae58d..a77a858 100644
--- a/ndn-cpp/c/errors.c
+++ b/ndn-cpp/c/errors.c
@@ -75,6 +75,8 @@
return "SocketTransport error in close";
case NDN_ERROR_Name_component_does_not_begin_with_the_expected_marker:
return "Name component does not begin with the expected marker";
+ case NDN_ERROR_Time_functions_are_not_supported_by_the_standard_library:
+ return "Time functions are not supported by the standard library";
default:
return "unrecognized ndn_Error code";
}