#include <iostream>
#include <fstream>
int main()
{
std::ifstream file_;
if (file_.is_open()) {
return 0;
}
file_.open("文件名", std::ios::binary);
std::string data;
data.resize(1024 * 4);
file_.read(&data[0], data.size());
//gcount()获取读到的字节数
std::int64_t read_n = file_.gcount();
if (read_n < 1024 * 4){
data.resize(read_n);
}
if (file_.peek() ==EOF){
std::cout << "末尾" << std::endl;
}
if (file_.is_open()){
file_.close();
}
}