一次性读取文件内容

两种方式

# include<sstream># include<fstream>

# include<string>int main(){    ifstream in("input.txt");    stringstream temp;    temp<<in.rdbuf();    string text = temp.str();//将字符串流转化为字符串    in.close();}

# include<fstream># include<string>int main(){    ifstream in("input.txt");    istreambuf_iterator<char> beg(in), end;//利用以字符为元素的流迭代器将文件流中所有的字符    string text(beg, end);//存入到字符串中    in.close();}