[Cppcms-users] Compile error: traits is not a template

[陈抒 <csf...@gm...>]

I have a correct class with no compilation error. All codes in response.h:
#ifndef __RESPONSE_H
#define __RESPONSE_H

namespace kaimei{
  class response {
  public:
    enum
{OK=0,SAVE_EMAIL_ERROR=1,CHANGE_PWD_ERROR=2,LOGIN_ERROR=3,CREATE_ACCOUNT_ERROR=4,
 SAVE_MESSAGE_ERROR=5,CHANGE_LANGUAGE_ERROR=6,NONE_CONTENT=7,LOAD_DISPLAY_ERROR=8,

 NONE_USER_ID=9,GET_MESSAGE_LOG_ERROR=10,QUIT_ERROR=11,NONE_ADMIN=12,BIND_ERROR=13,
 UPDATE_DESCRIPTION_ERROR=14,UNBIND_ERROR=15,LOAD_GROUPS_ERROR=16,UPDATE_GROUP_NAME_ERROR=17
    };
    int status;
    string message;
    string value;
  };
}

namespace cppcms {
  namespace json {

    template<>
      struct traits<kaimei::response> {

      static void set(value &v, kaimei::response const& in) {
v.set("status", in.status);
 v.set("message", in.message);
v.set("value", in.value);
      }
    };

  }
}

#endif


But I got error when compiling another class. It has group.h and group.cpp
file.

#ifndef __GROUP_H
#define __GROUP_H

#include <string>

namespace kaimei{
  class group {
  public:
    group();

    std::string id;
    std::string description;
    std::string name;
    int device_number;

    std::string json_string() const;
  };
}

namespace cppcms {
  namespace json {

    template<>
      struct traits<kaimei::group> {

      static void set(value &v, kaimei::group const& in) {
 v.set("id", in.id);
v.set("description", in.description);
 v.set("name", in.name);
v.set("deviceNumber", in.device_number);
      }
    };

  }
}


#endif

Error output:

[  3%] Building CXX object bin/CMakeFiles/cppweb.dir/groups.cpp.o
In file included from /home/chenshu/work/kaimei/cppweb/include/groups.h:6:0,
                 from /home/chenshu/work/kaimei/cppweb/src/groups.cpp:1:
/home/chenshu/work/kaimei/cppweb/include/group.h:24:14: error: ‘traits’ is
not a template
/home/chenshu/work/kaimei/cppweb/include/group.h:24:36: error: explicit
specialization of non-template ‘cppcms::json::traits’
/home/chenshu/work/kaimei/cppweb/include/group.h:26:23: error: ‘value’ has
not been declared
/home/chenshu/work/kaimei/cppweb/include/group.h: In static member function
‘static void cppcms::json::traits::set(int&, const kaimei::group&)’:
/home/chenshu/work/kaimei/cppweb/include/group.h:27:4: error: request for
member ‘set’ in ‘v’, which is of non-class type ‘int’
/home/chenshu/work/kaimei/cppweb/include/group.h:28:4: error: request for
member ‘set’ in ‘v’, which is of non-class type ‘int’
/home/chenshu/work/kaimei/cppweb/include/group.h:29:4: error: request for
member ‘set’ in ‘v’, which is of non-class type ‘int’
/home/chenshu/work/kaimei/cppweb/include/group.h:30:4: error: request for
member ‘set’ in ‘v’, which is of non-class type ‘int’


I am not good at template programming. Why did this happen?


陈抒
Best regards
http://blog.csdn.net/sheismylife