将字符串流传递给函数

Question

我正在尝试将字符串流从文件传递到函数.当我调用模板函数时,我收到一个错误:没有匹配函数来调用'toFile'.我验证了生命是打开的,数据已从它传递到stringstream.

#include <iostream>
#include <string>
#include <sstream>
#include <fstream>

using namespace std;

template <typename T1>
void toFile(string type, int NumOfElements, stringstream& ss){

   T1* myArray = new T1[NumOfElements];  // declaring new array to store the elements
   int value;

   for(int i = 0; i < NumOfElements; i++){ // store the elements in the array
       ss >> value;
       myArray[i] = value;
       cout << myArray[i] << " ";
   }
}


int main(int argc, char *argv[])
{
   ifstream ins;
   ofstream outs;
   string strg1;
   string type;
   int NumOfElements = 0;
   stringstream inputString;

   ins.open(argv[1]);

   if(argc<1) {
        cout << "please provide the file path." << endl;
            exit(1);
    }


   while (getline(ins, strg1)){ // reading  line from the file
   inputString.clear(); // clearing the inputString before reading a new line
   inputString << strg1;

   inputString >> type ;        // reading 1st element in a row
   inputString >> NumOfElements; // reading 2nd element in a row

   toFile(type, NumOfElements, inputString);
  }
   ins.close();
       return 0;
}

Answer 1

toFile是一个函数模板,因此只能使用模板参数调用它.有时候,函数模板可以从参数中推导出它们的参数,但由于T1你的参数列表中没有使用它们,所以无法推断它.您需要显式提供模板参数,例如:

toFile<int>(type, NumOfElements, inputString);