未传递给类函数的字符串向量

Question

我在将向量作为参数传递给类函数时遇到了一些问题。类在另一个文件中。这是我的代码：

main.cpp:

#include <iostream>
#include <vector>
#include <string>

#include "class1.h"

using namespace std;

int main() {

    vector<string> names;

    names.push_back("Bob");
    names.push_back("Gorge");
    names.push_back("Bill");
    names.push_back("Freddy");
    names.push_back("Daniel");
    names.push_back("Emily");


    class1 obj;
    obj.printVector(names);

    system("pause");
}

class1.h：

#pragma once

class class1
{
public:
    void printVector(std::vector<string>& names);
};

class1.cpp：

#include <string>

#include "class1.h"

using namespace std;

void class1::printVector(vector<string>& names) {

    for (unsigned int i = 0; i < names.size(); i++)
    {
        cout << names[i] << endl;
    }
}

我尝试对其他数据类型（int、char、floats...）做同样的事情，它奏效了。另外，当我将它们传递给 main.cpp 中的函数时，它可以工作。错误是：

- Severity  Code    Description Project File    Line    Suppression State
Error   C3203   'allocator': unspecialized class template can't be used as a template argument for template parameter '_Alloc', expected a real type    tesst   c:\users\...\documents\programs and games\tesst\tesst\class1.h  6

- Severity  Code    Description Project File    Line    Suppression State
Error   C3203   'allocator': unspecialized class template can't be used as a template argument for template parameter '_Alloc', expected a real type    tesst   c:\users\...\documents\programs and games\tesst\tesst\class1.h  6

- Severity  Code    Description Project File    Line    Suppression State
Error   C2923   'std::vector': 'string' is not a valid template type argument for parameter '_Ty'   tesst   c:\users\...\documents\programs and games\tesst\tesst\class1.h  6   

- Severity  Code    Description Project File    Line    Suppression State
Error   C2923   'std::vector': 'string' is not a valid template type argument for parameter '_Ty'   tesst   c:\users\...\documents\programs and games\tesst\tesst\class1.h  6   

- Severity  Code    Description Project File    Line    Suppression State
Error   C2065   'string': undeclared identifier tesst   c:\users\...\documents\programs and games\tesst\tesst\class1.h  6   

- Severity  Code    Description Project File    Line    Suppression State
Error   C2065   'string': undeclared identifier tesst   c:\users\...\documents\programs and games\tesst\tesst\class1.h  6   

- Severity  Code    Description Project File    Line    Suppression State
Error   C2664   'void class1::printVector(std::vector &)': cannot convert argument 1 from 'std::vector<std::string,std::allocator<_Ty>>' to 'std::vector &' tesst   c:\users\...\documents\programs and games\tesst\tesst\main.cpp  22  

- Severity  Code    Description Project File    Line    Suppression State
Error   C2511   'void class1::printVector(std::vector<std::string,std::allocator<_Ty>> &)': overloaded member function not found in 'class1'    tesst   c:\users\...\documents\programs and games\tesst\tesst\class1.cpp    9   

请帮忙！ 谢谢你

Answer 1

class1.h 不包括<string> 或<vector>.

在包含 class1.h 之前，您恰好在源文件中包含 <string>（这不是您应该依赖的东西！），因此您“摆脱了”前一个遗漏。

在后一种情况下，class1.cpp 根本不知道vector 是什么意思。

修复您的包含。

Answer 2

您的问题不在于将参数传递给类。 以下代码在这里工作：

#include <iostream>
#include <vector>
#include <string>

using namespace std;

class class1 {
public:
    void printVector(std::vector<string>& names);

};

void class1::printVector(vector<string>& names) {

    for (unsigned int i = 0; i < names.size(); i++)
    {
        cout << names[i] << endl;
    }
}

int main() {

    vector<string> names;

    names.push_back("Bob");
    names.push_back("Gorge");
    names.push_back("Bill");
    names.push_back("Freddy");
    names.push_back("Daniel");
    names.push_back("Emily");


    class1 obj;
    obj.printVector(names);
        return 0;
}

正如之前在 Orbit 中的 Lightness Races 所提到的，您的问题不在于 class1 的向量和字符串