| I/O manipulators | ||||
| Print functions(C++23) | ||||
| C-style I/O | ||||
| Buffers | ||||
basic_spanbuf (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) |
| Public member functions | ||||
(C++23) | ||||
(C++23) | ||||
(C++23) | ||||
(C++23) | ||||
| Protected member functions | ||||
(C++23) | ||||
(C++23) | ||||
(C++23) | ||||
| Non-member functions | ||||
(C++23) |
Defined in header <spanstream> | ||
template< class CharT, | (since C++23) | |
std::basic_spanbuf is astd::basic_streambuf whose associated character sequence is a memory-resident sequence of arbitrary characters, which can be initialized from or made available as an instance ofstd::span<CharT>.
std::basic_spanbuf performs I/O on a fixed buffer, and therefore it does not attempt to obtain a new buffer when the underlying buffer is exhausted.
Several typedefs for common character types are provided:
Defined in header <spanstream> | |
| Type | Definition |
std::spanbuf | std::basic_spanbuf<char> |
std::wspanbuf | std::basic_spanbuf<wchar_t> |
Contents |
| Member type | Definition |
char_type | CharT[edit] |
traits_type | Traits; the program is ill-formed ifTraits::char_type is notCharT.[edit] |
int_type | Traits::int_type[edit] |
pos_type | Traits::pos_type[edit] |
off_type | Traits::off_type[edit] |
| Member name | Definition |
mod(private) | Astd::ios_base::openmode recording the open mode. (exposition-only member object*) |
buf(private) | Astd::span<CharT> referencing the underlying buffer. (exposition-only member object*) |
Public member functions | |
constructs abasic_spanbuf object(public member function)[edit] | |
(destructor) [virtual] | destroys thebasic_spanbuf object(virtual public member function) |
assigns abasic_spanbuf object(public member function)[edit] | |
swaps twobasic_spanbuf objects(public member function)[edit] | |
| obtains or initializes an underlying buffer according to mode (public member function)[edit] | |
Protected member functions | |
[virtual] | attempts to replace the controlled character sequence with an array (virtual protected member function)[edit] |
[virtual] | repositions the next pointer in the input sequence, output sequence, or both, using relative addressing (virtual protected member function)[edit] |
[virtual] | repositions the next pointer in the input sequence, output sequence, or both using absolute addressing (virtual protected member function)[edit] |
| specializes thestd::swap algorithm (function template)[edit] |
| Member type | Definition |
char_type | CharT[edit] |
traits_type | Traits; the program is ill-formed ifTraits::char_type is notCharT.[edit] |
int_type | Traits::int_type[edit] |
pos_type | Traits::pos_type[edit] |
off_type | Traits::off_type[edit] |
[virtual] | destructs thebasic_streambuf object(virtual public member function of std::basic_streambuf<CharT,Traits>)[edit] |
Locales | |
| changes the associated locale and invokesimbue() (public member function of std::basic_streambuf<CharT,Traits>)[edit] | |
| obtains a copy of the associated locale (public member function of std::basic_streambuf<CharT,Traits>)[edit] | |
Positioning | |
| invokessetbuf() (public member function of std::basic_streambuf<CharT,Traits>)[edit] | |
| invokesseekoff() (public member function of std::basic_streambuf<CharT,Traits>)[edit] | |
| invokesseekpos() (public member function of std::basic_streambuf<CharT,Traits>)[edit] | |
| invokessync() (public member function of std::basic_streambuf<CharT,Traits>)[edit] | |
Get area | |
| obtains the number of characters immediately available in the get area (public member function of std::basic_streambuf<CharT,Traits>)[edit] | |
| advances the input sequence, then reads one character without advancing again (public member function of std::basic_streambuf<CharT,Traits>)[edit] | |
(removed in C++17) | reads one character from the input sequence and advances the sequence (public member function of std::basic_streambuf<CharT,Traits>)[edit] |
| reads one character from the input sequence without advancing the sequence (public member function of std::basic_streambuf<CharT,Traits>)[edit] | |
| invokesxsgetn() (public member function of std::basic_streambuf<CharT,Traits>)[edit] | |
Put area | |
| writes one character to the put area and advances the next pointer (public member function of std::basic_streambuf<CharT,Traits>)[edit] | |
| invokesxsputn() (public member function of std::basic_streambuf<CharT,Traits>)[edit] | |
Putback | |
| puts one character back in the input sequence (public member function of std::basic_streambuf<CharT,Traits>)[edit] | |
| moves the next pointer in the input sequence back by one (public member function of std::basic_streambuf<CharT,Traits>)[edit] | |
constructs abasic_streambuf object(protected member function)[edit] | |
(C++11) | replaces abasic_streambuf object(protected member function)[edit] |
(C++11) | swaps twobasic_streambuf objects(protected member function)[edit] |
Locales | |
[virtual] | reacts to a change of the associated locale (virtual protected member function of std::basic_streambuf<CharT,Traits>)[edit] |
Positioning | |
[virtual] | replaces the buffer with user-defined array, if permitted (virtual protected member function of std::basic_streambuf<CharT,Traits>)[edit] |
[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>)[edit] |
[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>)[edit] |
[virtual] | synchronizes the buffers with the associated character sequence (virtual protected member function of std::basic_streambuf<CharT,Traits>)[edit] |
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>)[edit] |
[virtual] | reads characters from the associated input sequence to the get area (virtual protected member function of std::basic_streambuf<CharT,Traits>)[edit] |
[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>)[edit] |
[virtual] | reads multiple characters from the input sequence (virtual protected member function of std::basic_streambuf<CharT,Traits>)[edit] |
| returns a pointer to the beginning, current character and the end of the get area (protected member function)[edit] | |
| advances the next pointer in the input sequence (protected member function)[edit] | |
| repositions the beginning, next, and end pointers of the input sequence (protected member function)[edit] | |
Put area | |
[virtual] | writes multiple characters to the output sequence (virtual protected member function of std::basic_streambuf<CharT,Traits>)[edit] |
[virtual] | writes characters to the associated output sequence from the put area (virtual protected member function of std::basic_streambuf<CharT,Traits>)[edit] |
| returns a pointer to the beginning, current character and the end of the put area (protected member function)[edit] | |
| advances the next pointer of the output sequence (protected member function)[edit] | |
| repositions the beginning, next, and end pointers of the output sequence (protected member function)[edit] | |
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>)[edit] |
std::basic_spanbuf does not own the underlying buffer.
It is the responsibility of programmers to ensure the underlying buffer is in its lifetime when used by astd::basic_spanbuf object. Additional synchronization may be needed if more than one thread operates the same underlying buffer through differentstd::basic_spanbuf objects.
| Feature-test macro | Value | Std | Feature |
|---|---|---|---|
__cpp_lib_spanstream | 202106L | (C++23) | std::spanbuf,std::spanstream |
| implements raw string device (class template)[edit] | |
(deprecated in C++98)(removed in C++26) | implements raw character array device (class)[edit] |
