Difference between revisions of "cpp/io/basic syncbuf"
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template< | template< | ||
class CharT, | class CharT, | ||
Revision as of 09:07, 13 November 2017
| Defined in header <syncstream>
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||
| template< class CharT, |
(since C++20) | |
std::basic_syncbuf is a wrapper for a std::basic_streambuf (provided at construction time as a pointer). It accumulates output in its own internal buffer, and atomically transmits its entire contents to the wrapped buffer on destruction and when explicitly requested, so that they appear as a contiguous sequence of characters.
Typical implementation of std::basic_syncbuf holds a pointer to the wrapped std::basic_streambuf and a boolean flag indicating whether the buffer will transmit its contents to the wrapped buffer on sync (flush).
Two specializations for common character types are also defined:
| Defined in header
<sstream> | |
| Type | Definition |
syncbuf
|
basic_syncbuf<char> |
wsyncbuf
|
basic_syncbuf<wchar_t> |
Contents |
Member types
| Member type | Definition |
char_type
|
CharT
|
traits_type
|
Traits; the program is ill-formed if Traits::char_type is not CharT.
|
int_type
|
Traits::int_type
|
pos_type
|
Traits::pos_type
|
off_type
|
Traits::off_type
|
allocator_type
|
Allocator |
streambuf_type
|
std::basic_streambuf<CharT, Traits> |
Member functions
Public member functions | |
constructs a basic_syncbuf object (public member function) | |
assigns a basic_syncbuf object (public member function) | |
Protected member functions | |
| either emits, or records a pending flush, depending on the current emit-on-sync policy (public member function) | |
Non-member functions
| specializes the std::swap algorithm (function template) |
Inherited from std::basic_streambuf
Member types
| Member type | Definition |
char_type
|
CharT
|
traits_type
|
Traits; the program is ill-formed if Traits::char_type is not CharT.
|
int_type
|
Traits::int_type
|
pos_type
|
Traits::pos_type
|
off_type
|
Traits::off_type
|
Member functions
| [virtual] |
destructs the basic_streambuf object (virtual public member function of std::basic_streambuf<CharT,Traits>)
|
Locales | |
| invokes imbue() (public member function of std::basic_streambuf<CharT,Traits>)
| |
| obtains a copy of the associated locale (public member function of std::basic_streambuf<CharT,Traits>)
| |
Positioning | |
| invokes setbuf() (public member function of std::basic_streambuf<CharT,Traits>)
| |
| invokes seekoff() (public member function of std::basic_streambuf<CharT,Traits>)
| |
| invokes seekpos() (public member function of std::basic_streambuf<CharT,Traits>)
| |
| invokes sync() (public member function of std::basic_streambuf<CharT,Traits>)
| |
Get area | |
| obtains the number of characters immediately available in the get area (public member function of std::basic_streambuf<CharT,Traits>)
| |
| advances the input sequence, then reads one character without advancing again (public member function of std::basic_streambuf<CharT,Traits>)
| |
| (removed in C++17) |
reads one character from the input sequence and advances the sequence (public member function of std::basic_streambuf<CharT,Traits>)
|
| reads one character from the input sequence without advancing the sequence (public member function of std::basic_streambuf<CharT,Traits>)
| |
| invokes xsgetn() (public member function of std::basic_streambuf<CharT,Traits>)
| |
Put area | |
| writes one character to the put area and advances the next pointer (public member function of std::basic_streambuf<CharT,Traits>)
| |
| invokes xsputn() (public member function of std::basic_streambuf<CharT,Traits>)
| |
Putback | |
| puts one character back in the input sequence (public member function of std::basic_streambuf<CharT,Traits>)
| |
| moves the next pointer in the input sequence back by one (public member function of std::basic_streambuf<CharT,Traits>)
| |
Protected member functions
constructs a basic_streambuf object (protected member function) | |
| (C++11) |
replaces a basic_streambuf object (protected member function) |
| (C++11) |
swaps two basic_streambuf objects (protected member function) |
Locales | |
| [virtual] |
changes the associated locale (virtual protected member function of std::basic_streambuf<CharT,Traits>)
|
Positioning | |
| [virtual] |
replaces the buffer with user-defined array, if permitted (virtual protected member function of std::basic_streambuf<CharT,Traits>)
|
| [virtual] |
repositions the next pointer in the input sequence, output sequence, or both, using relative addressing (virtual protected member function of std::basic_streambuf<CharT,Traits>)
|
| [virtual] |
repositions the next pointer in the input sequence, output sequence, or both using absolute addressing (virtual protected member function of std::basic_streambuf<CharT,Traits>)
|
| [virtual] |
synchronizes the buffers with the associated character sequence (virtual protected member function of std::basic_streambuf<CharT,Traits>)
|
Get area | |
| [virtual] |
obtains the number of characters available for input in the associated input sequence, if known (virtual protected member function of std::basic_streambuf<CharT,Traits>)
|
| [virtual] |
reads characters from the associated input sequence to the get area (virtual protected member function of std::basic_streambuf<CharT,Traits>)
|
| [virtual] |
reads characters from the associated input sequence to the get area and advances the next pointer (virtual protected member function of std::basic_streambuf<CharT,Traits>)
|
| [virtual] |
reads multiple characters from the input sequence (virtual protected member function of std::basic_streambuf<CharT,Traits>)
|
| returns a pointer to the beginning, current character and the end of the get area (protected member function) | |
| advances the next pointer in the input sequence (protected member function) | |
| repositions the beginning, next, and end pointers of the input sequence (protected member function) | |
Put area | |
| [virtual] |
writes multiple characters to the output sequence (virtual protected member function of std::basic_streambuf<CharT,Traits>)
|
| [virtual] |
writes characters to the associated output sequence from the put area (virtual protected member function of std::basic_streambuf<CharT,Traits>)
|
| returns a pointer to the beginning, current character and the end of the put area (protected member function) | |
| advances the next pointer of the output sequence (protected member function) | |
| repositions the beginning, next, and end pointers of the output sequence (protected member function) | |
Putback | |
| [virtual] |
puts a character back into the input sequence, possibly modifying the input sequence (virtual protected member function of std::basic_streambuf<CharT,Traits>)
|
