define ostream operator<<总结两个结构

时间:2011-09-22 05:48:01

标签: c++

我有以下代码来汇总两个结构元素

#include <iostream>
#include <ostream>
#include <fstream>
using namespace std;
struct USC{

 int dollars;
 int cents;
 USC operator+(const USC o){
     USC  temp={0,0};
     temp.cents=cents+o.cents;
     temp.dollars=dollars+o.dollars;
     if (temp.cents>=100){
         temp.dollars+=1;
         temp.cents-=100;

     }
        return temp;  
 }


}; /* <-- make sure that semicolon is there */
      ostream& operator<<(ostream &output, const USCurrency &o) {
             output<<o.dollars<<"  "<<o.cents<<endl;
      return output;

      }
int main(){

    USC a={2,50};
    USC b={1,75};
      USC c=a+b;

         cout<<c<<endl;




 return 0;
}

但这是一个错误列表

1>------ Build started: Project: struct, Configuration: Debug Win32 ------
1>  struct.cpp
1>c:\users\datuashvili\documents\visual studio 2010\projects\struct\struct\struct.cpp(23): error C2143: syntax error : missing ';' before '&'
1>c:\users\datuashvili\documents\visual studio 2010\projects\struct\struct\struct.cpp(23): error C2872: 'ostream' : ambiguous symbol
1>          could be 'c:\users\datuashvili\documents\visual studio 2010\projects\struct\struct\struct.cpp(23) : USC ostream'
1>          or       'c:\program files\microsoft visual studio 10.0\vc\include\iosfwd(636) : std::ostream'
1>c:\users\datuashvili\documents\visual studio 2010\projects\struct\struct\struct.cpp(23): error C2872: 'ostream' : ambiguous symbol
1>          could be 'c:\users\datuashvili\documents\visual studio 2010\projects\struct\struct\struct.cpp(23) : USC ostream'
1>          or       'c:\program files\microsoft visual studio 10.0\vc\include\iosfwd(636) : std::ostream'
1>c:\users\datuashvili\documents\visual studio 2010\projects\struct\struct\struct.cpp(23): error C2065: 'output' : undeclared identifier
1>c:\users\datuashvili\documents\visual studio 2010\projects\struct\struct\struct.cpp(23): error C2059: syntax error : 'const'
1>c:\users\datuashvili\documents\visual studio 2010\projects\struct\struct\struct.cpp(23): error C2143: syntax error : missing ';' before '{'
1>c:\users\datuashvili\documents\visual studio 2010\projects\struct\struct\struct.cpp(23): error C2447: '{' : missing function header (old-style formal list?)
1>c:\users\datuashvili\documents\visual studio 2010\projects\struct\struct\struct.cpp(34): error C2679: binary '<<' : no operator found which takes a right-hand operand of type 'USC' (or there is no acceptable conversion)
1>          c:\program files\microsoft visual studio 10.0\vc\include\ostream(679): could be 'std::basic_ostream<_Elem,_Traits> &std::operator <<<char,std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,const char *)'
1>          with
1>          [
1>              _Elem=char,
1>              _Traits=std::char_traits<char>
1>          ]
1>          c:\program files\microsoft visual studio 10.0\vc\include\ostream(726): or       'std::basic_ostream<_Elem,_Traits> &std::operator <<<char,std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,char)'
1>          with
1>          [
1>              _Elem=char,
1>              _Traits=std::char_traits<char>
1>          ]
1>          c:\program files\microsoft visual studio 10.0\vc\include\ostream(764): or       'std::basic_ostream<_Elem,_Traits> &std::operator <<<std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,const char *)'
1>          with
1>          [
1>              _Elem=char,
1>              _Traits=std::char_traits<char>
1>          ]
1>          c:\program files\microsoft visual studio 10.0\vc\include\ostream(811): or       'std::basic_ostream<_Elem,_Traits> &std::operator <<<std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,char)'
1>          with
1>          [
1>              _Elem=char,
1>              _Traits=std::char_traits<char>
1>          ]
1>          c:\program files\microsoft visual studio 10.0\vc\include\ostream(937): or       'std::basic_ostream<_Elem,_Traits> &std::operator <<<std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,const signed char *)'
1>          with
1>          [
1>              _Elem=char,
1>              _Traits=std::char_traits<char>
1>          ]
1>          c:\program files\microsoft visual studio 10.0\vc\include\ostream(944): or       'std::basic_ostream<_Elem,_Traits> &std::operator <<<std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,signed char)'
1>          with
1>          [
1>              _Elem=char,
1>              _Traits=std::char_traits<char>
1>          ]
1>          c:\program files\microsoft visual studio 10.0\vc\include\ostream(951): or       'std::basic_ostream<_Elem,_Traits> &std::operator <<<std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,const unsigned char *)'
1>          with
1>          [
1>              _Elem=char,
1>              _Traits=std::char_traits<char>
1>          ]
1>          c:\program files\microsoft visual studio 10.0\vc\include\ostream(958): or       'std::basic_ostream<_Elem,_Traits> &std::operator <<<std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,unsigned char)'
1>          with
1>          [
1>              _Elem=char,
1>              _Traits=std::char_traits<char>
1>          ]
1>          c:\program files\microsoft visual studio 10.0\vc\include\ostream(968): or       'std::basic_ostream<_Elem,_Traits> &std::operator <<<char,std::char_traits<char>,USC>(std::basic_ostream<_Elem,_Traits> &&,_Ty)'
1>          with
1>          [
1>              _Elem=char,
1>              _Traits=std::char_traits<char>,
1>              _Ty=USC
1>          ]
1>          c:\program files\microsoft visual studio 10.0\vc\include\ostream(1085): or       'std::basic_ostream<_Elem,_Traits> &std::operator <<<char,std::char_traits<char>>(std::basic_ostream<_Elem,_Traits> &,const std::error_code &)'
1>          with
1>          [
1>              _Elem=char,
1>              _Traits=std::char_traits<char>
1>          ]
1>          c:\program files\microsoft visual studio 10.0\vc\include\ostream(186): or       'std::basic_ostream<_Elem,_Traits> &std::basic_ostream<_Elem,_Traits>::operator <<(std::basic_ostream<_Elem,_Traits> &(__cdecl *)(std::basic_ostream<_Elem,_Traits> &))'
1>          with
1>          [
1>              _Elem=char,
1>              _Traits=std::char_traits<char>
1>          ]
1>          c:\program files\microsoft visual studio 10.0\vc\include\ostream(192): or       'std::basic_ostream<_Elem,_Traits> &std::basic_ostream<_Elem,_Traits>::operator <<(std::basic_ios<_Elem,_Traits> &(__cdecl *)(std::basic_ios<_Elem,_Traits> &))'
1>          with
1>          [
1>              _Elem=char,
1>              _Traits=std::char_traits<char>
1>          ]
1>          c:\program files\microsoft visual studio 10.0\vc\include\ostream(199): or       'std::basic_ostream<_Elem,_Traits> &std::basic_ostream<_Elem,_Traits>::operator <<(std::ios_base &(__cdecl *)(std::ios_base &))'
1>          with
1>          [
1>              _Elem=char,
1>              _Traits=std::char_traits<char>
1>          ]
1>          c:\program files\microsoft visual studio 10.0\vc\include\ostream(206): or       'std::basic_ostream<_Elem,_Traits> &std::basic_ostream<_Elem,_Traits>::operator <<(std::_Bool)'
1>          with
1>          [
1>              _Elem=char,
1>              _Traits=std::char_traits<char>
1>          ]
1>          c:\program files\microsoft visual studio 10.0\vc\include\ostream(226): or       'std::basic_ostream<_Elem,_Traits> &std::basic_ostream<_Elem,_Traits>::operator <<(short)'
1>          with
1>          [
1>              _Elem=char,
1>              _Traits=std::char_traits<char>
1>          ]
1>          c:\program files\microsoft visual studio 10.0\vc\include\ostream(260): or       'std::basic_ostream<_Elem,_Traits> &std::basic_ostream<_Elem,_Traits>::operator <<(unsigned short)'
1>          with
1>          [
1>              _Elem=char,
1>              _Traits=std::char_traits<char>
1>          ]
1>          c:\program files\microsoft visual studio 10.0\vc\include\ostream(280): or       'std::basic_ostream<_Elem,_Traits> &std::basic_ostream<_Elem,_Traits>::operator <<(int)'
1>          with
1>          [
1>              _Elem=char,
1>              _Traits=std::char_traits<char>
1>          ]
1>          c:\program files\microsoft visual studio 10.0\vc\include\ostream(305): or       'std::basic_ostream<_Elem,_Traits> &std::basic_ostream<_Elem,_Traits>::operator <<(unsigned int)'
1>          with
1>          [
1>              _Elem=char,
1>              _Traits=std::char_traits<char>
1>          ]
1>          c:\program files\microsoft visual studio 10.0\vc\include\ostream(325): or       'std::basic_ostream<_Elem,_Traits> &std::basic_ostream<_Elem,_Traits>::operator <<(long)'
1>          with
1>          [
1>              _Elem=char,
1>              _Traits=std::char_traits<char>
1>          ]
1>          c:\program files\microsoft visual studio 10.0\vc\include\ostream(345): or       'std::basic_ostream<_Elem,_Traits> &std::basic_ostream<_Elem,_Traits>::operator <<(unsigned long)'
1>          with
1>          [
1>              _Elem=char,
1>              _Traits=std::char_traits<char>
1>          ]
1>          c:\program files\microsoft visual studio 10.0\vc\include\ostream(366): or       'std::basic_ostream<_Elem,_Traits> &std::basic_ostream<_Elem,_Traits>::operator <<(__int64)'
1>          with
1>          [
1>              _Elem=char,
1>              _Traits=std::char_traits<char>
1>          ]
1>          c:\program files\microsoft visual studio 10.0\vc\include\ostream(386): or       'std::basic_ostream<_Elem,_Traits> &std::basic_ostream<_Elem,_Traits>::operator <<(unsigned __int64)'
1>          with
1>          [
1>              _Elem=char,
1>              _Traits=std::char_traits<char>
1>          ]
1>          c:\program files\microsoft visual studio 10.0\vc\include\ostream(407): or       'std::basic_ostream<_Elem,_Traits> &std::basic_ostream<_Elem,_Traits>::operator <<(float)'
1>          with
1>          [
1>              _Elem=char,
1>              _Traits=std::char_traits<char>
1>          ]
1>          c:\program files\microsoft visual studio 10.0\vc\include\ostream(427): or       'std::basic_ostream<_Elem,_Traits> &std::basic_ostream<_Elem,_Traits>::operator <<(double)'
1>          with
1>          [
1>              _Elem=char,
1>              _Traits=std::char_traits<char>
1>          ]
1>          c:\program files\microsoft visual studio 10.0\vc\include\ostream(447): or       'std::basic_ostream<_Elem,_Traits> &std::basic_ostream<_Elem,_Traits>::operator <<(long double)'
1>          with
1>          [
1>              _Elem=char,
1>              _Traits=std::char_traits<char>
1>          ]
1>          c:\program files\microsoft visual studio 10.0\vc\include\ostream(467): or       'std::basic_ostream<_Elem,_Traits> &std::basic_ostream<_Elem,_Traits>::operator <<(const void *)'
1>          with
1>          [
1>              _Elem=char,
1>              _Traits=std::char_traits<char>
1>          ]
1>          c:\program files\microsoft visual studio 10.0\vc\include\ostream(487): or       'std::basic_ostream<_Elem,_Traits> &std::basic_ostream<_Elem,_Traits>::operator <<(std::basic_streambuf<_Elem,_Traits> *)'
1>          with
1>          [
1>              _Elem=char,
1>              _Traits=std::char_traits<char>
1>          ]
1>          while trying to match the argument list '(std::ostream, USC)'
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========
请大家帮帮我什么错?

2 个答案:

答案 0 :(得分:6)

在结构定义之后(第22行的大括号之后)需要一个分号

我编辑了帖子以显示它的去向

答案 1 :(得分:1)

编译器对你说:

  

c:\ users \ datuashvili \ documents \ visual studio 2010 \ projects \ struct \ struct \ struct.cpp(23):错误C2143:语法错误:缺少';'在'&amp;'之前

通常,当您遇到编译错误时,请从第一个开始......( - `