| I/O manipulators | ||||
| Print functions(C++23) | ||||
| C-style I/O | ||||
| Buffers | ||||
(C++23) | ||||
(C++98/26*) | ||||
(C++20) | ||||
| Streams | ||||
| Abstractions | ||||
| File I/O | ||||
| String I/O | ||||
| Array I/O | ||||
(C++23) | ||||
(C++23) | ||||
(C++23) | ||||
(C++98/26*) | ||||
(C++98/26*) | ||||
(C++98/26*) | ||||
| Synchronized Output | ||||
(C++20) | ||||
| Types | ||||
| Error category interface | ||||
(C++11) | ||||
(C++11) |
| Member functions | ||||
| Formatting | ||||
| Locales | ||||
| Internal extensible array | ||||
| Miscellaneous | ||||
| Member classes | ||||
| Member types | ||||
ios_base::openmode | ||||
typedef/* implementation defined */ openmode; | ||
staticconstexpr openmode app =/* implementation defined */; staticconstexpr openmode binary =/* implementation defined */; | ||
staticconstexpr openmode noreplace=/* implementation defined */; | (since C++23) | |
Specifies available file open flags. It is aBitmaskType, the following constants are defined:
| Constant | Explanation |
| app | seek to the end of stream before each write |
| binary | open inbinary mode |
| in | open for reading |
| out | open for writing |
| trunc | discard the contents of the stream when opening |
| ate | seek to the end of stream immediately after open |
| noreplace(C++23) | open in exclusive mode |
#include <fstream>#include <iostream>#include <string> int main(){constchar* fname="unique_name.txt"; // write to a temporary stream objectstd::fstream(fname, std::ios::out| std::ios::trunc)<<"Hi"; std::string s;std::fstream(fname, std::ios::in)>> s;std::cout<< s<<'\n';}
Output:
Hi
| opens a file and configures it as the associated character sequence (public member function of std::basic_filebuf<CharT,Traits>)[edit] | |
constructs abasic_stringbuf object(public member function of std::basic_stringbuf<CharT,Traits,Allocator>)[edit] |
