Input/output library
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Error category interface
std::basic_spanbuf
Public member functions
Protected member functions
Non-member functions
std::basic_spanbuf
is a std::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 of std::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:
Type
Definition
std::spanbuf
std::basic_spanbuf<char>
std::wspanbuf
std::basic_spanbuf<wchar_t>
[edit] Member types
Member type
Definition
traits_type
Traits
; the program is ill-formed if
Traits::char_type
is not
CharT
.
[edit]
int_type
Traits::int_type
[edit]
pos_type
Traits::pos_type
[edit]
off_type
Traits::off_type
[edit]
[edit] Data members
Member name
Definition
buf
(private)
A
std::span <CharT> referencing the underlying buffer.
(exposition-only member object*)
[edit] Member functions
Public member functions
constructs a
basic_spanbuf
object
(public member function) [edit]
destroys the
basic_spanbuf
object
(virtual public member function)
assigns a
basic_spanbuf
object
(public member function) [edit]
swaps two
basic_spanbuf
objects
(public member function) [edit]
obtains or initializes an underlying buffer according to mode
(public member function) [edit]
Protected member functions
attempts to replace the controlled character sequence with an array
(virtual protected member function) [edit]
repositions the next pointer in the input sequence, output sequence, or both, using relative addressing
(virtual protected member function) [edit]
repositions the next pointer in the input sequence, output sequence, or both using absolute addressing
(virtual protected member function) [edit]
[edit] Non-member functions
Member types
Member type
Definition
traits_type
Traits
; the program is ill-formed if
Traits::char_type
is not
CharT
.
[edit]
int_type
Traits::int_type
[edit]
pos_type
Traits::pos_type
[edit]
off_type
Traits::off_type
[edit]
Member functions
destructs the
basic_streambuf
object
(virtual public member function of std::basic_streambuf<CharT,Traits>
) [edit]
Locales
changes the associated locale and invokes
imbue() (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
invokes
setbuf() (public member function of std::basic_streambuf<CharT,Traits>
) [edit]
invokes
seekoff() (public member function of std::basic_streambuf<CharT,Traits>
) [edit]
invokes
seekpos() (public member function of std::basic_streambuf<CharT,Traits>
) [edit]
invokes
sync() (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]
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]
invokes
xsgetn() (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]
invokes
xsputn() (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]
Protected member functions
constructs a
basic_streambuf
object
(protected member function) [edit]
replaces a
basic_streambuf
object
(protected member function) [edit]
swaps two
basic_streambuf
objects
(protected member function) [edit]
Locales
reacts to a change of the associated locale
(virtual protected member function of std::basic_streambuf<CharT,Traits>
) [edit]
Positioning
replaces the buffer with user-defined array, if permitted
(virtual protected member function of std::basic_streambuf<CharT,Traits>
) [edit]
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]
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]
synchronizes the buffers with the associated character sequence
(virtual protected member function of std::basic_streambuf<CharT,Traits>
) [edit]
Get area
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]
reads characters from the associated input sequence to the get area
(virtual protected member function of std::basic_streambuf<CharT,Traits>
) [edit]
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]
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
writes multiple characters to the output sequence
(virtual protected member function of std::basic_streambuf<CharT,Traits>
) [edit]
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
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 a std::basic_spanbuf
object. Additional synchronization may be needed if more than one thread operates the same underlying buffer through different std::basic_spanbuf
objects.
[edit] See also
implements raw string device
(class template) [edit]
(deprecated in C++98)(removed in C++26)
implements raw character array device
(class) [edit]