c++ - 错误 : expected constructor, 析构函数，或 ‘&’ token 之前的类型转换

Question

我写了以下代码。问题应该是 istringstream 函数。我做错了什么？提前致谢。

//read a string from input with a istringstream function and output the string   
word by word;
//1.the function takes and returns an istringstream&
//2.the function reads the stream until it hits eof
//the function should print the  contents of an istringstream object
#include <iostream>
#include <string>
#include <sstream>

istringstream& read(istringstream& input)
{

string string, word;
while(getline(input,string), !input.eof())
{
    if (input)      
    {
        istringstream instring(string);
        instring>>word;
        cout<<word<<'_'<<ends;
    }
    if (input.bad())
        throw runtime_error("data is corrupted");
    if (input.fail())
        cerr<<"data failed, try again"<<ends;
    input.close();
    input.clear();
}
return istringstream&;
}

int main ()
{   
    cout<<"enter a string"<<endl;
read(cin);
}

这个输出错误是:(第9行)

 error: expected constructor, destructor, or type conversion before ‘&’ token

Answer 1

改变:

return istringstream&;

到:

return input;

但是假设您不使用返回值，您可以将 read() 的返回类型更改为 void 并且什么都不返回。