defined in the header file <fstream>
template< class CharT, |
Class Template basic_fstream
Implements high-level input/output over file-based streams. It gives the high-level interface of std::basic_iostream to file-based buffering ( std::basic_filebuf ).
std::basic_fstream
A typical implementation of maintains only one non-exported data member: an instance of std::basic_filebuf<CharT, Traits> .
inheritance diagram
Also defines two specializations for common character types:
type | definition |
fstream |
basic_fstream<char> |
wfstream |
basic_fstream<wchar_t> |
member type
member type | definition |
char_type |
CharT |
traits_type |
Traits ; if Traits::char_type not CharT the program is ill-formed. |
int_type |
Traits::int_type |
pos_type |
Traits::pos_type |
off_type |
Traits::off_type |
member function
(Constructor) |
Construct file stream (public member function) |
(destructor) [virtual] (implicit declaration) |
Destroy basic_fstream and associated buffers, and close the file (virtual public member function) |
operator= (C++11) |
Move file stream (public member function) |
swap (C++11) |
Exchange two file streams (public member function) |
rdbuf |
Returns the underlying unhandled file device object (public member function) |
file operation |
|
is_open |
Checks if a stream has an associated file (public member function) |
open |
Open a file and associate it with a stream (public member function) |
close |
close associated file (public member function) |
non-member function
std::swap(std::basic_fstream) (C++11) |
specialization of the std::swap algorithm (function template) |
Inherited from std::basic_istream
member function
formatted input |
|
operator>> |
Extract formatted data ( std::basic_istream<CharT,Traits> public member function of |
plain input |
|
get |
Read and take away (remove like a pointer to move to the next element) a character from the stream ( std::basic_istream<CharT,Traits> public member function) |
peek |
Reads but does not take (does not remove like pointer does not move) a character ( std::basic_istream<CharT,Traits> public member function of) |
rage |
Undo the character just taken (removed, similar to a pointer back one position) in the stream ( std::basic_istream<CharT,Traits> public member function) |
putback |
Returns a character to the input stream ( std::basic_istream<CharT,Traits> public member function of) |
getline |
Read and remove characters until the given character is found ( std::basic_istream<CharT,Traits> public member function of) |
ignore |
reads and fetches and discards characters until the given character is found ( std::basic_istream<CharT,Traits> public member function of) |
read |
Read and take a block of characters ( std::basic_istream<CharT,Traits> public member function) |
readsome |
Read and take away an already available character block ( std::basic_istream<CharT,Traits> public member function of |
gcount |
返回上次无格式输出操作所取走的字符数量 ( std::basic_istream<CharT,Traits> 的公开成员函数) |
寻位 |
|
tellg |
返回输入位置指示器 ( std::basic_istream<CharT,Traits> 的公开成员函数) |
seekg |
设置输入位置指示器 ( std::basic_istream<CharT,Traits> 的公开成员函数) |
杂项 |
|
sync |
与底层存储设备同步 ( std::basic_istream<CharT,Traits> 的公开成员函数) |
成员类
sentry |
实现为输出操作准备流的基本逻辑 ( std::basic_istream<CharT,Traits> 的公开成员类) |
继承自 std::basic_ostream
成员函数
有格式输出 |
|
operator<< |
插入带格式数据 ( std::basic_ostream<CharT,Traits> 的公开成员函数) |
无格式输出 |
|
put |
插入字符 ( std::basic_ostream<CharT,Traits> 的公开成员函数) |
write |
插入字符块 ( std::basic_ostream<CharT,Traits> 的公开成员函数) |
寻位 |
|
tellp |
返回输出位置指示器 ( std::basic_ostream<CharT,Traits> 的公开成员函数) |
seekp |
设置输出位置指示器 ( std::basic_ostream<CharT,Traits> 的公开成员函数) |
杂项 |
|
flush |
与底层存储设备同步 ( std::basic_ostream<CharT,Traits> 的公开成员函数) |
成员类
sentry |
为输出操作实现流准备的基本逻辑 ( std::basic_ostream<CharT,Traits> 的公开成员类) |
继承自 std::basic_ios
成员类型
成员类型 | 定义 |
char_type |
CharT |
traits_type |
Traits |
int_type |
Traits::int_type |
pos_type |
Traits::pos_type |
off_type |
Traits::off_type |
成员函数
状态函数 |
|
good |
检查是否没有发生错误,例如是否可执行I/O操作 ( std::basic_ios<CharT,Traits> 的公开成员函数) |
eof |
检查是否到达了文件末尾 ( std::basic_ios<CharT,Traits> 的公开成员函数) |
fail |
检查是否发生了可恢复的错误 ( std::basic_ios<CharT,Traits> 的公开成员函数) |
bad |
检查是否已发生不可恢复的错误 ( std::basic_ios<CharT,Traits> 的公开成员函数) |
operator! |
检查是否有错误发生(fail() 的同义词) ( std::basic_ios<CharT,Traits> 的公开成员函数) |
operator void*operator bool (C++11 前)(C++11 起) |
检查是否没有发生错误(!fail()的同义词) ( std::basic_ios<CharT,Traits> 的公开成员函数) |
rdstate |
返回状态标志 ( std::basic_ios<CharT,Traits> 的公开成员函数) |
setstate |
设置状态标志 ( std::basic_ios<CharT,Traits> 的公开成员函数) |
clear |
修改状态标志 ( std::basic_ios<CharT,Traits> 的公开成员函数) |
格式化 |
|
copyfmt |
复制格式化信息 ( std::basic_ios<CharT,Traits> 的公开成员函数) |
fill |
管理填充字符 ( std::basic_ios<CharT,Traits> 的公开成员函数) |
杂项 |
|
exceptions |
管理异常掩码 ( std::basic_ios<CharT,Traits> 的公开成员函数) |
imbue |
设置本地环境 ( std::basic_ios<CharT,Traits> 的公开成员函数) |
rdbuf |
管理相关的流缓冲区 ( std::basic_ios<CharT,Traits> 的公开成员函数) |
tie |
管理绑定的流 ( std::basic_ios<CharT,Traits> 的公开成员函数) |
narrow |
窄化字符 ( std::basic_ios<CharT,Traits> 的公开成员函数) |
widen |
拓宽字符 ( std::basic_ios<CharT,Traits> 的公开成员函数) |
继承自 std::ios_base
成员函数
格式化 |
|
flags |
管理格式标志 ( std::ios_base 的公开成员函数) |
setf |
设置特定格式标志 ( std::ios_base 的公开成员函数) |
unsetf |
清除特定格式的标志 ( std::ios_base 的公开成员函数) |
precision |
管理浮点操作的精度 ( std::ios_base 的公开成员函数) |
width |
管理域的宽度 ( std::ios_base 的公开成员函数) |
本地环境 |
|
imbue |
设置本地环境 ( std::ios_base 的公开成员函数) |
getloc |
返回当前本地环境 ( std::ios_base 的公开成员函数) |
内部可扩展数组 |
|
xalloc [静态] |
返回能安全用作 pword() 和 iword() 下标的程序范围内独有的整数 ( std::ios_base 的公开静态成员函数) |
iword |
如果有必要的话,调整私有存储的大小,并且访问位于提供的下标的long元素 ( std::ios_base 的公开成员函数) |
pword |
若需要则重置私有存储的大小,并访问位于指定下标的 void* 元素 ( std::ios_base 的公开成员函数) |
杂项 |
|
register_callback |
注册事件回调函数 ( std::ios_base 的公开成员函数) |
sync_with_stdio [静态] |
设置C++和C的IO库是否可以互操作 ( std::ios_base 的公开静态成员函数) |
成员类 |
|
failure |
流异常 ( std::ios_base 的公开成员类) |
Init |
初始化标准流对象 ( std::ios_base 的公开成员类) |
成员类型和常量 |
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类型 | 解释 | ||||||||||||||||||||||||||||||||||||||
openmode |
流打开模式类型 亦定义下列常量:
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fmtflags |
格式化标志类型 亦定义下列常量:
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iostate |
流状态类型 亦定义下列常量:
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seekdir |
寻位方向类型 亦定义下列常量:
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event |
指定事件类型 (枚举) |
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event_callback |
回调函数类型 (typedef) |