定义于头文件 <fstream>

template<     class CharT,     class Traits = std::char_traits<CharT> > class basic_ofstream : public std::basic_ostream<CharT, Traits>

 类模板 basic_ofstream 实现文件上基于流的高层输出操作。它将 std::basic_ostream 的高层接口赋予基于文件的流缓冲（ std::basic_filebuf ）。

std::basic_ofstream 典型实现只保有一个非导出成员： std::basic_filebuf<CharT, Traits> 的实例。

 亦对常用字符类型定义二个特化：

类型	定义
ofstream	basic_ofstream<char>
wofstream	basic_ofstream<wchar_t>

文件操作

关闭关联文件

std::basic_ofstream<CharT,Traits>::close

void close();

关闭关联文件。

等效地调用 rdbuf()->close() 。若操作期间出现错误，则调用 setstate(failbit) 。

参数

（无）

返回值

（无）

注意

此函数为 basic_ofstream 的析构函数在流对象离开作用域时调用，通常不直接调用。

调用示例

#include <fstream>
#include <utility>
#include <string>
#include <iostream>int main()
{std::ofstream ofstream1("test1.txt", std::ios::in);std::ofstream ofstream2("test2.txt", std::ios::in);std::ofstream ofstream3("test3.txt", std::ios::in);std::cout << "ofstream1 is: " << (ofstream1.is_open() ? "true" : "false") << std::endl;std::cout << "ofstream2 is: " << (ofstream2.is_open() ? "true" : "false") << std::endl;std::cout << "ofstream3 is: " << (ofstream3.is_open() ? "true" : "false") << std::endl;std::cout << std::endl;std::cout << "std::ofstream close" << std::endl;ofstream1.close();ofstream2.close();ofstream3.close();std::cout << std::endl;std::cout << "ofstream1 is: "<< (ofstream1.is_open() ? "true" : "false") << std::endl;std::cout << "ofstream2 is: "<< (ofstream2.is_open() ? "true" : "false") << std::endl;std::cout << "ofstream3 is: "<< (ofstream3.is_open() ? "true" : "false") << std::endl;std::cout << std::endl;return 0;
}

输出

 

非成员函数

特化 std::swap 算法

std::swap(std::basic_ofstream)

template< class CharT, class Traits > void swap( basic_ofstream<CharT,Traits> &lhs, basic_ofstream<CharT,Traits> &rhs );

 为 std::basic_ofstream 特化 std::swap 算法。交换 lhs 与 rhs 的状态。等效地调用 lhs.swap(rhs) 。

参数

lhs, rhs

-

要交换状态的流

返回值

（无）

异常

（无）

调用示例

#include <fstream>
#include <utility>
#include <string>
#include <iostream>int main()
{std::ofstream ofstream1("test1.txt", std::ios::out);std::cout << "ofstream1 is: "<< (ofstream1 ? "true" : "false") << std::endl;std::ofstream ofstream2("test2.txt", std::ios::out);std::cout << "ofstream2 is: "<< (ofstream2 ? "true" : "false") << std::endl;std::cout << std::endl;ofstream1 << "hello 1" << " ";ofstream2 << "hello 2" << " ";//为 std::basic_ofstream 特化 std::swap 算法。//交换 lhs 与 rhs 的状态。等效地调用 lhs.swap(rhs) 。std::cout << "std::swap(ofstream1, ofstream2) " << std::endl;std::swap(ofstream1, ofstream2);ofstream1 << "hello 1" << " ";ofstream2 << "hello 2" << " ";ofstream1.close();ofstream2.close();std::cout << std::endl;std::ifstream ifstream1("test1.txt", std::ios::in);std::cout << "ifstream1 is: "<< (ifstream1.is_open() ? "true" : "false") << std::endl;if (ifstream1.is_open()){std::cout << ifstream1.rdbuf() << std::endl;}std::cout << std::endl;std::ifstream ifstream2("test2.txt", std::ios::in);std::cout << "ifstream2 is: "<< (ifstream2.is_open() ? "true" : "false") << std::endl;if (ifstream2.is_open()){std::cout << ifstream2.rdbuf() << std::endl;}std::cout << std::endl;return 0;
}

输出