std::basic_filebuf::is_open
bool is_open() const; | | |
|---|
回报true如果最近的电话open()成功了，没有人呼吁close()从那以后。
参数
%280%29
返回值
true如果相关文件打开，false否则。
注记
此函数通常由std::basic_fstream::is_open()...
例
二次
#include <fstream>
#include <iostream>
int main()
{
std::ifstream fs("test.txt");
std::filebuf fb;
fb.open("test.txt", std::ios_base::in);
std::cout << std::boolalpha
<< "direct call: " << fb.is_open() << '\n'
<< "through streambuf: " << fs.rdbuf()->is_open() << '\n'
<< "through fstream: " << fs.is_open() << '\n';
}二次
产出：
二次
direct call: true
through streambuf: true
through fstream: true二次
另见
open | opens a file and configures it as the associated character sequence (public member function) |
|---|---|
close | flushes the put area buffer and closes the associated file (public member function) |
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