Namespaces
Variants
Views
Actions

std::basic_stringbuf

From cppreference.com
< cpp‎ | io
 
 
Input/output library
I/O manipulators
Print functions (C++23)
C-style I/O
Buffers
basic_stringbuf
(deprecated in C++98)
Streams
Abstractions
File I/O
String I/O
Array I/O
(deprecated in C++98)
(deprecated in C++98)
(deprecated in C++98)
Synchronized Output
Types
Error category interface
(C++11)
 
 
Defined in header <sstream>
template<

    class CharT,
    class Traits = std::char_traits<CharT>,
    class Allocator = std::allocator<CharT>
> class basic_stringbuf

    : public std::basic_streambuf<CharT, Traits>

std::basic_stringbuf 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::basic_string.

Typical implementations of std::basic_stringbuf hold an object of type std::basic_string or equivalent resizable sequence container directly as a data member and use it as both the controlled character sequence (the array where the six pointers of std::basic_streambuf are pointing to) and as the associated character sequence (the source of characters for all input operations and the target for the output).

In addition, a typical implementation holds a data member of type std::ios_base::openmode to indicate the I/O mode of the associated stream (input-only, output-only, input/output, at-end, etc).

If over-allocation strategy is used by overflow(), an additional high-watermark pointer may be stored to track the last initialized character.

(since C++11)

Several typedefs for common character types are provided:

Defined in header <sstream>
Type Definition
std::stringbuf std::basic_stringbuf<char>
std::wstringbuf std::basic_stringbuf<wchar_t>

Contents

[edit] Member types

Member type Definition
char_type CharT[edit]
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]
allocator_type Allocator[edit]

[edit] Exposition-only members

buf the std::basic_string<CharT, Traits, Allocator> used as the underlying buffer
(exposition-only member object*)
mode the std::ios_base::openmode of the associated stream
(exposition-only member object*)
initializes the input and output sequences
(exposition-only member function*)

[edit] Public member functions

constructs a basic_stringbuf object
(public member function) [edit]
(C++11)
assigns a basic_stringbuf object
(public member function) [edit]
(C++11)
swaps two basic_stringbuf objects
(public member function) [edit]
(destructor)
[virtual] (implicitly declared)
destructs a basic_stringbuf object and the string it holds
(virtual public member function) [edit]
replaces or obtains a copy of the associated character string
(public member function) [edit]
obtains a copy of the allocator associated with the internal sequence container
(public member function) [edit]
(C++20)
obtains a view over the underlying character sequence
(public member function) [edit]

[edit] Protected member functions

[virtual]
returns the next character available in the input sequence
(virtual protected member function) [edit]
[virtual]
puts a character back into the input sequence
(virtual protected member function) [edit]
[virtual]
appends a character to the output sequence
(virtual protected member function) [edit]
[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]

[edit] Non-member functions

specializes the std::swap algorithm
(function template) [edit]

Inherited from std::basic_streambuf

Member types

Member type Definition
char_type CharT[edit]
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

[virtual]
destructs the basic_streambuf object
(virtual public member function of std::basic_streambuf<CharT,Traits>) [edit]
Locales
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]
(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]
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]
(C++11)
replaces a basic_streambuf object
(protected member function) [edit]
(C++11)
swaps two basic_streambuf objects
(protected member function) [edit]
Locales
[virtual]
changes 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]