input.open( filename.c_str(), std::ifstream::in ); if( input.rdstate() & std::ios::failbit )if语句那一行怎么理解?解答:1:iostate rdstate ( ) const; 返回的是iostate,简单的说也就是一个int数值.用2进制数据的某一个位置设置为1表示一种状态2:failbit 的定义如下,二进制数据的第二位为1的...
if( input.rdstate() & std::ios::failbit ) 1. 2. 3. if语句那一行怎么理解? 解答: 1:iostate rdstate ( ) const; 返回的是iostate,简单的说也就是一个int数值.用2进制数据的某一个位置设置为1表示一种状态 2:failbit 的定义如下,二进制数据的第二位为1的时候说明是该数据。 static const _Iostat...
1：iostate rdstate ( ) const; 返回的是iostate,简单的说也就是一个int数值.用2进制数据的某一个...
Does it make sense to setstd::ios_base::failbitto throw exceptions, for output streams? As in: 1 2 3 4 5 std::ofstream output_file("out.txt"); output_file.exceptions(std::ios_base::badbit | std::ios_base::failbit);// ... ...
failbit); } catch (const std::ios_base::failure& e) { std::cout << "捕获了 ios_base::failure。\n" << "解释字符串:" << e.what() << '\n' << "错误码:" << e.code() << '\n'; } } 可能的输出: 捕获了 ios_base::failure。解释字符串:ios_base::clear: 未指定的 ...
#include <fstream>#include <iostream>intmain(){std::ifstreamf("doesn't exist");try{f.exceptions(f.failbit);}catch(conststd::ios_base::failure&e){std::cout<<"Caught an ios_base::failure.\n"<<"Explanatory string: "<<e.what()<<'\n'<<"Error code: "<<e.code()<<'\n';}} ...
#include <iostream>#include <fstream>intmain(){std::ifstreamf("doesn't exist");try{f.exceptions(f.failbit);}catch(conststd::ios_base::failure&e){std::cout<<"Caught an ios_base::failure.\n"<<"Explanatory string: "<<e.what()<<'\n'<<"Error code: "<<e.code()<<'\n';}} ...
为promise 设置异常,此后 promise 的共享状态变标志变为 ready,例子如下,线程1从终端接收一个整数,线程2将该整数打印出来,如果线程1接收一个非整数,则为 promise 设置一个异常(failbit) ,线程2 在std::future::get 是抛出该异常。 #include <iostream>//std::cin, std::cout, std::ios#include <functional...
Stream在读取数据至end-of-file时,不仅设置ios::eofbit,而且还会设置ios::failbit。所以,当发生异常时,要注意使用成员函数eof()来区分到底是哪类异常。 try { cin.clear(); cin.exceptions( std::ios::eofbit | std::ios::failbit ); ...
In brief: std::ifstream is; is.exceptions( is.exceptions() | std::ios_base::failbit | std::ios_base::badbit ); // handle different exceptions as 'file not found', 'permission denied' try { is.open("my_valid_file.json"); const auto &jsonF...