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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]