Found the following significant warnings:
  libjson/Source/JSONSharedString.h:297:17: warning: ‘json_shared_string::len’ will be initialized after [-Wreorder]
  libjson/Source/JSONSharedString.h:295:40: warning:   ‘json_shared_string::json_shared_string_internal* json_shared_string::_str’ [-Wreorder]
  libjson/Source/JSONSharedString.h:180:9: warning:   when initialized here [-Wreorder]
  libjson/Source/JSONSharedString.h:182:9: warning:   when initialized here [-Wreorder]
  libjson/Source/JSONDefs/GNU_C.h:58:28: warning: dynamic exception specifications are deprecated in C++11 [-Wdeprecated]
  libjson/Source/JSONStream.h:79:7: warning: ‘JSONStream::state’ will be initialized after [-Wreorder]
  libjson/Source/JSONStream.h:76:28: warning:   ‘void (* JSONStream::call)(void*, void*)’ [-Wreorder]
  JSONStream.cpp:8:1: warning:   when initialized here [-Wreorder]
  libjson/Source/JSONStream.h:77:27: warning: ‘JSONStream::err_call’ will be initialized after [-Wreorder]
  libjson/Source/JSONStream.h:75:17: warning:   ‘json_string JSONStream::buffer’ [-Wreorder]
  JSONStream.cpp:12:1: warning:   when initialized here [-Wreorder]
  libjson.cpp:84:24: warning: catching polymorphic type ‘class std::invalid_argument’ by value [-Wcatch-value=]
  libjson.cpp:95:23: warning: catching polymorphic type ‘class std::invalid_argument’ by value [-Wcatch-value=]
  libjson/Source/internalJSONNode.h:257:18: warning: ‘internalJSONNode::_name_encoded’ will be initialized after [-Wreorder]
  libjson/Source/internalJSONNode.h:256:17: warning:   ‘json_string internalJSONNode::_name’ [-Wreorder]
  internalJSONNode.cpp:78:1: warning:   when initialized here [-Wreorder]
  libjson.cpp:501:24: warning: catching polymorphic type ‘class std::out_of_range’ by value [-Wcatch-value=]
  libjson.cpp:512:24: warning: catching polymorphic type ‘class std::out_of_range’ by value [-Wcatch-value=]
  libjson.cpp:525:24: warning: catching polymorphic type ‘class std::out_of_range’ by value [-Wcatch-value=]
See ‘/data/gannet/ripley/R/packages/tests-devel/RJSONIO.Rcheck/00install.out’ for details.