coutのクラスのcoutプログラム

私はC++で小さなプログラムを書いています。クラスがあります。クラス内のcoutを使ってデータを出力できますか？のようなcout < < "良い時"; < <オペレータを過負荷にする必要はありませんか？私はそれをしようとしていますが、それはいくつかのエラーだけでは動作しません。クラス内でそれを持つcoutを介してデータを出力する方法。
CPPファイル：coutのクラスのcoutプログラム

#include "University.hpp" 
#include "Course.hpp" 
//#include "Lecture.hpp" 
#include <string> 
#include <sstream> 
#include <iostream> 

using namespace std; 

University::University() { 
} 
University::University(int capacity, string uni) { 
    university = uni; 
    cap = capacity; 
    length = 0; 
    myCourse = new Course[cap];  
} 

University::University(University& orig) { 
    copy(orig); 
} 

University::~University() { 
    delete [] myCourse; 
} 

University & University:: operator=(University & other){ 
    if(this != &other){ 
     delete [] myCourse; 
     copy(other); 
    } 
    return *this; 
} 

void University:: copy(University & other){ 
    if(this != &other){ 
     length = other.length; 
     cap = other.cap; 
     myCourse = new Course[cap]; 

     for(int x = 0; x < length; x++){ 
      myCourse[x] = other.myCourse[x]; 
     }  
    }  
} 
void University:: addCourse(Course syllabus){ 
    if(length == cap){ 
     cap *= 2; 
     Course * temp = new Course[cap]; 

     for(int x = 0; x < length; x++){ 
      temp[x] = myCourse[x]; 
     } 
     myCourse = temp;   
    } 
    myCourse[length] = syllabus; 
    length++; 
} 
void University::listAll(){ 
    for(int x = 0; x < length; x++){ 
     cout << toString();// toString(); 
    } 
} 

friend ostream& operator<<(ostream& os, const University& uni){ 
    os <<uni.university <<uni.myCourse; 
    return os; 
} 

string University::toString(){ 
    ostringstream ans; 

    for(int x = 0; x < length; x++){ 
    ans << "The University " << university << " teaches " << myCourse[x] << myCourse[x].toString() << endl; 
    } 
    return ans.str(); 
}

ヘッダー：

#include <string> 
#include "Course.hpp" 

using namespace std; 

#ifndef UNIVERSITY_HPP 
#define UNIVERSITY_HPP 

class University { 
    friend ostream& operator<< (ostream& os, const University& uni); 
public: 
    University(); 
    University(int capacity, string UoL); 
    University(University& orig); 
    ~University(); 
    void copy(University & other); 
    University & operator=(University & other); 
    void addCourse(Course syllabus); 
    void listAll(); 
    string toString(); 

private: 
    Course * myCourse; 
    int length; 
    int cap; 
    string university; 
}; 

#endif /* UNIVERSITY_HPP */

エラー：

g++ -c -g -MMD -MP -MF build/Debug/Cygwin-Windows/University.o.d -o build/Debug/Cygwin-Windows/University.o University.cpp 
University.cpp:72: error: can't initialize friend function `operator<<' 
University.cpp:72: error: friend declaration not in class definition 
University.cpp: In member function `std::string University::toString()': 
University.cpp:81: error: no match for 'operator<<' in 'std::operator<< [with _Traits = std::char_traits<char>](((std::basic_ostream<char, std::char_traits<char> >&)(+std::operator<< [with _CharT = char, _Traits = std::char_traits<char>, _Alloc = std::allocator<char>](((std::basic_ostream<char, std::char_traits<char> >&)(+std::operator<< [with _Traits = std::char_traits<char>](((std::basic_ostream<char, std::char_traits<char> >&)((std::basic_ostream<char, std::char_traits<char> >*)(&ans))), ((const char*)"The University ")))), ((const std::basic_string<char, std::char_traits<char>, std::allocator<char> >&)((const std::basic_string<char, std::char_traits<char>, std::allocator<char> >*)(((std::string*)((University*)this)) + 12u)))))), ((const char*)" teaches ")) << *(((University*)this)->University::myCourse + (+(((unsigned int)x) * 16u)))' 
/usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/ostream.tcc:63: note: candidates are: std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(std::basic_ostream<_CharT, _Traits>&(*)(std::basic_ostream<_CharT, _Traits>&)) [with _CharT = char, _Traits = std::char_traits<char>] 
/usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/ostream.tcc:74: note:     std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(std::basic_ios<_CharT, _Traits>&(*)(std::basic_ios<_CharT, _Traits>&)) [with _CharT = char, _Traits = std::char_traits<char>] 
/usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/ostream.tcc:86: note:     std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(std::ios_base&(*)(std::ios_base&)) [with _CharT = char, _Traits = std::char_traits<char>] 
/usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/ostream.tcc:121: note:     std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(long int) [with _CharT = char, _Traits = std::char_traits<char>] 
/usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/ostream.tcc:155: note:     std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(long unsigned int) [with _CharT = char, _Traits = std::char_traits<char>] 
/usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/ostream.tcc:98: note:     std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(bool) [with _CharT = char, _Traits = std::char_traits<char>] 
/usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/ostream:178: note:     std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(short int) [with _CharT = char, _Traits = std::char_traits<char>] 
/usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/ostream:189: note:     std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(short unsigned int) [with _CharT = char, _Traits = std::char_traits<char>] 
/usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/ostream:193: note:     std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(int) [with _CharT = char, _Traits = std::char_traits<char>] 
/usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/ostream:204: note:     std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(unsigned int) [with _CharT = char, _Traits = std::char_traits<char>] 
/usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/ostream.tcc:179: note:     std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(long long int) [with _CharT = char, _Traits = std::char_traits<char>] 
/usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/ostream.tcc:214: note:     std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(long long unsigned int) [with _CharT = char, _Traits = std::char_traits<char>] 
/usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/ostream.tcc:238: note:     std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(double) [with _CharT = char, _Traits = std::char_traits<char>] 
/usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/ostream:219: note:     std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(float) [with _CharT = char, _Traits = std::char_traits<char>] 
/usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/ostream.tcc:261: note:     std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(long double) [with _CharT = char, _Traits = std::char_traits<char>] 
/usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/ostream.tcc:284: note:     std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(const void*) [with _CharT = char, _Traits = std::char_traits<char>] 
/usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/ostream.tcc:307: note:     std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(std::basic_streambuf<_CharT, _Traits>*) [with _CharT = char, _Traits = std::char_traits<char>] 
University.cpp:72: note:     std::ostream& operator<<(std::ostream&, const University&) 
/usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/ostream:504: note:     std::basic_ostream<char, _Traits>& std::operator<<(std::basic_ostream<char, _Traits>&, const unsigned char*) [with _Traits = std::char_traits<char>] 
/usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/ostream:499: note:     std::basic_ostream<char, _Traits>& std::operator<<(std::basic_ostream<char, _Traits>&, const signed char*) [with _Traits = std::char_traits<char>] 
/usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/ostream.tcc:612: note:     std::basic_ostream<char, _Traits>& std::operator<<(std::basic_ostream<char, _Traits>&, const char*) [with _Traits = std::char_traits<char>] 
/usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/ostream.tcc:567: note:     std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT, _Traits>&, const char*) [with _CharT = char, _Traits = std::char_traits<char>] 
/usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/ostream:465: note:     std::basic_ostream<char, _Traits>& std::operator<<(std::basic_ostream<char, _Traits>&, unsigned char) [with _Traits = std::char_traits<char>] 
/usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/ostream:460: note:     std::basic_ostream<char, _Traits>& std::operator<<(std::basic_ostream<char, _Traits>&, signed char) [with _Traits = std::char_traits<char>] 
/usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/ostream.tcc:505: note:     std::basic_ostream<char, _Traits>& std::operator<<(std::basic_ostream<char, _Traits>&, char) [with _Traits = std::char_traits<char>] 
/usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/ostream:449: note:     std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT, _Traits>&, char) [with _CharT = char, _Traits = std::char_traits<char>] 
make[2]: *** [build/Debug/Cygwin-Windows/University.o] Error 1 
make[1]: *** [.build-conf] Error 2 
make: *** [.build-impl] Error 2 
make[2]: Leaving directory `/cygdrive/g/Aristotelis/C++/Assessment_2' 
make[1]: Leaving directory `/cygdrive/g/Aristotelis/C++/Assessment_2' 

BUILD FAILED (exit value 2, total time: 3s)

出典

2011-11-16 ucas

*「いくつかのエラーだけでは動作しません」*は問題の説明ではありません。あなたが試したことを、*と*あなたが持っているエラーの全文を示してください。 –

ああ、「いくつかのエラーのみ」。それはそれを絞り込むべきです。 –

質問は何ですか？ –

あなたは引数がCourseことでostringstream::operator<<を呼び出すようにしようとしています。 Courseにもoperator<<を定義する必要があります。申し訳ありませんが、前にこれを逃しました。 operator<<(ostream&, const University&)の定義からfriendも削除する必要がありますが、これはクラス定義内でのみ必要なためです。

出典

2011-11-16 01:12:08

この例を試してみてください。

#include <iostream> 
using namespace std; 

class A 
{ 
    friend ostream& operator<<(ostream& os, const A& a); 
    int _member; 
    public: 
    A() : _member(0) 
     { } 

    A(int member) : _member(member) 
     { } 
}; 

ostream& operator<<(ostream&os, const A& a) 
{ 
    os << a._member; 
    return os; 
} 

int main() 
{ 
    A a(5); 
    cout << a << endl; 
    return 0; 
}

お客様のニーズに合わせて適切に再生してください。だから、

出典

2011-11-16 01:12:22 dave

University.cpp:72: error: can't initialize friend function `operator<<' 
University.cpp:72: error: friend declaration not in class definition 
University.cpp: In member function `std::string University::toString()':

、我々はメンバ関数 `のstd ::文字列大学::のtoString（）」でを見て、見つける：

ans << ... << myCourse[x] << ...;

は、あなたは、このための過負荷を持っていますか？

friend ostream& operator<< (ostream& os, const Course& uni);

ここに示すコードのいずれにも該当しません。

出典

2011-11-16 01:18:25

coutのクラスのcoutプログラム

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