what does this mean [Werror=reorder]

[Irani Acharjamayum]

Could someone explain me what is this error  [Werror=reorder]

In file included from ../src/lte/model/lte-pdcp.cc:24:0:

./ns3/lte-pdcp.h: In constructor ‘ns3::LtePdcp::LtePdcp()’:

./ns3/lte-pdcp.h:168:12: error: ‘ns3::LtePdcp::pdcp_decisionlwip’ will be initialized after [-Werror=reorder]

   uint32_t pdcp_decisionlwip;

            ^

./ns3/lte-pdcp.h:142:19: error:   ‘ns3::LtePdcpSapUser* ns3::LtePdcp::m_pdcpSapUser’ [-Werror=reorder]

   LtePdcpSapUser* m_pdcpSapUser;

                   ^

../src/lte/model/lte-pdcp.cc:71:1: error:   when initialized here [-Werror=reorder]

 LtePdcp::LtePdcp ()

[Tom Henderson]

Usually this is an initialization order problem; please see this stack
overflow discussion:
https://stackoverflow.com/questions/12222417/why-should-i-initialize-member-variables-in-the-order-theyre-declared-in

[Irani Acharjamayum]

Thank you Sir. Will check.