异常处理和打开文件？ [英] Exception Handling and Opening a File?

问题描述

是否可以使用文件打开例外来代替 .is_open（）？

Is it possible to use exceptions with file opening as an alternative to using .is_open()?

例如：

ifstream input;

try{
  input.open("somefile.txt");
}catch(someException){
  //Catch exception here
}

如果是这样，什么类型是 someException ？

If so, what type is someException?

推荐答案

< a href = http://en.cppreference.com/w/cpp/io/basic_ios/exceptions rel = noreferrer> http://en.cppreference.com/w/cpp/io/basic_ios/exceptions

也请阅读此答案 11085151 引用了此文章

Also read this answer 11085151 which references this article

// ios::exceptions
#include <iostream>
#include <fstream>
using namespace std;

void do_something_with(char ch) {} // Process the character 

int main () {
  ifstream file;
  file.exceptions ( ifstream::badbit ); // No need to check failbit
  try {
    file.open ("test.txt");
    char ch;
    while (file.get(ch)) do_something_with(ch);
    // for line-oriented input use file.getline(s)
  }
  catch (const ifstream::failure& e) {
    cout << "Exception opening/reading file";
  }

  file.close();

  return 0;
}

在灯箱

编辑：通过const引用 2145147

catch exceptions by const reference 2145147

编辑：从异常集中删除了故障位。添加了URL，以获得更好的答案。

removed failbit from the exception set. Added URLs to better answers.

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