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c++ - 头文件中的类给出许多错误

问题描述

我想制作一个类库，以便我可以在我的代码中使用它。这就是为什么我将我的课程分成 2 个文件 - s_int.h 和 s_int.cpp 但是编译给出了太多与课程相关的错误。通常我会看到一些与构造函数和析构函数错误相关的“匿名聚合”。这是我的代码：

主.cpp：

#include "s_int.h"
#include <iostream>
#include <string>
using namespace std;
int main()
{
    s_int integer;
    integer = "11111111111111111111111111111111111";
    s_int integer1(integer);
    cout << integer.integer << "\n";
    cout << integer1.integer << "\n";
}

s_int.cpp

#include <bits/stdc++.h>
#include "s_int.h"
using namespace std;
 
    s_int::s_int(std::string inp) 
    {
        this-> integer = inp;
    }
    s_int::s_int(const s_int &inp) 
    {
        this-> integer = inp.integer;
    }
    void s_int::operator = (const string &inp )
    {
        integer = inp;
    }
    void s_int::operator = (const s_int &inp )
    {
        integer = inp.integer;
    }

s_int.h

#include <bits/stdc++.h>
#ifndef s_int
#define s_int
using namespace std;
class s_int
{
    public:
        string integer = "";
        s_int(std::string inp = "") ;
        s_int(const s_int &inp) ;
        void operator = (const string &inp );
        void operator = (const s_int &inp );
};
#endif

编译错误（如果需要）

$ g++ main.cpp s_int.h s_int.cpp
main.cpp: In function ‘int main()’:
main.cpp:7:11: error: ‘integer’ was not declared in this scope
    7 |     s_int integer;
      |           ^~~~~~~
main.cpp:9:11: error: ‘integer1’ was not declared in this scope
    9 |     s_int integer1(integer);
      |           ^~~~~~~~
s_int.h:9:26: error: expected ‘)’ before ‘inp’
    9 |         s_int(std::string inp = "") ;
      |              ~           ^~~~
      |                          )
s_int.h:10:15: error: expected unqualified-id before ‘const’
   10 |         s_int(const s_int &inp) ;
      |               ^~~~~
s_int.h:10:15: error: expected ‘)’ before ‘const’
   10 |         s_int(const s_int &inp) ;
      |              ~^~~~~
      |               )
s_int.h:13:33: error: ‘inp’ has not been declared
   13 |         s_int operator + (s_int inp );
      |                                 ^~~
s_int.h:8:16: error: member ‘std::string <unnamed class>::integer’ with constructor not allowed in anonymous aggregate
    8 |         string integer = "";
      |                ^~~~~~~
s_int.h:8:16: error: member ‘std::string <unnamed class>::integer’ with destructor not allowed in anonymous aggregate
s_int.h:8:16: error: member ‘std::string <unnamed class>::integer’ with copy assignment operator not allowed in anonymous aggregate
s_int.h:14:2: error: abstract declarator ‘&lt;unnamed class>’ used as declaration
   14 | };
      |  ^
In file included from s_int.cpp:2:
s_int.h:9:26: error: expected ‘)’ before ‘inp’
    9 |         s_int(std::string inp = "") ;
      |              ~           ^~~~
      |                          )
s_int.h:10:15: error: expected unqualified-id before ‘const’
   10 |         s_int(const s_int &inp) ;
      |               ^~~~~
s_int.h:10:15: error: expected ‘)’ before ‘const’
   10 |         s_int(const s_int &inp) ;
      |              ~^~~~~
      |               )
s_int.h:13:33: error: ‘inp’ has not been declared
   13 |         s_int operator + (s_int inp );
      |                                 ^~~
s_int.h:8:16: error: member ‘std::string <unnamed class>::integer’ with constructor not allowed in anonymous aggregate
    8 |         string integer = "";
      |                ^~~~~~~
s_int.h:8:16: error: member ‘std::string <unnamed class>::integer’ with destructor not allowed in anonymous aggregate
s_int.h:8:16: error: member ‘std::string <unnamed class>::integer’ with copy assignment operator not allowed in anonymous aggregate
s_int.h:14:2: error: abstract declarator ‘&lt;unnamed class>’ used as declaration
   14 | };
      |  ^
s_int.cpp:5:17: error: expected id-expression before ‘(’ token
    5 |     s_int::s_int(std::string inp)
      |                 ^
s_int.cpp:9:17: error: expected id-expression before ‘(’ token
    9 |     s_int::s_int(const s_int &inp)
      |                 ^
s_int.cpp:13:47: error: ‘void operator=(const string&)’ should have been declared inside ‘::’
   13 |     void s_int::operator = (const string &inp )
      |                                               ^
s_int.cpp:13:15: error: ‘void operator=(const string&)’ must be a nonstatic member function
   13 |     void s_int::operator = (const string &inp )
      |               ^~
s_int.cpp:17:46: error: ‘void operator=(const int&)’ should have been declared inside ‘::’
   17 |     void s_int::operator = (const s_int &inp )
      |                                              ^
s_int.cpp:17:15: error: ‘void operator=(const int&)’ must be a nonstatic member function
   17 |     void s_int::operator = (const s_int &inp )
      |               ^~
s_int.cpp:21:29: error: expected constructor, destructor, or type conversion before ‘(’ token
   21 |     s_int s_int::operator + (s_int inp )
      |                             ^

标签： c++classheaderdestructoraggregation

解决方案

#define s_int

会让编译器用s_int空字符串替换类名，会造成麻烦。

使用另一个名称来定义包含保护。

使用

#pragma once

相反，如果您的环境支持此功能也很好。

你也必须#include "s_int.h"像main.cpp@NathanOliver 所说的那样添加。

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