std:: strstreambuf
From cppreference.com
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Defined in header
<strstream>
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||
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class
strstreambuf
:
public
std::
basic_streambuf
<
char
>
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(deprecated in C++98)
(removed in C++26) |
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std::strstreambuf
is a
std::basic_streambuf
whose associated character sequence is a character array, which may be constant (e.g. a string literal), modifiable but not dynamic (e.g. a stack-allocated array), or dynamic, in which case the
std::strstreambuf
may be allowed to reallocate the array as necessary to accommodate output (e.g. by calling
delete
[
]
and
new
[
]
or user-provided functions).
Typical implementation of a
std::strstreambuf
holds four private data members:
1)
buffer state, a bitmask type which can represent any combination of the four values "allocated" (destructor will deallocate), "constant" (output not allowed), "dynamic" (output may reallocate), or "frozen" (deallocation and reallocation are not allowed)
2)
allocated buffer size (the beginning of the buffer does not need a special data member, it may be stored in the inherited pointer
eback()
)
3)
pointer to user-provided allocation function
4)
pointer to user-provided deallocation function.
Notes
After any call to
str()
on a stream with a dynamic buffer, a call to
freeze(false)
is required to allow the
strstreambuf
destructor to deallocate the buffer when necessary.
strstreambuf
has been deprecated since C++98 and removed since C++26
. The recommended replacement is
std::spanbuf
(since C++23)
.
Member functions
Public member functions |
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constructs a
strstreambuf
object
(public member function) |
|
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[virtual]
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destructs a
strstreambuf
object, optionally deallocating the character array
(virtual public member function) |
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sets/clears the frozen state of the buffer
(public member function) |
|
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marks the buffer frozen and returns the beginning pointer of the input sequence
(public member function) |
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returns the next pointer minus the beginning pointer in the output sequence: the number of characters written
(public member function) |
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Protected member functions |
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[virtual]
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reads a character from the input sequence without advancing the next pointer
(virtual protected member function) |
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[virtual]
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backs out the input sequence to unget a character
(virtual protected member function) |
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[virtual]
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appends a character to the output sequence, may reallocate or initially allocate the buffer if dynamic and not frozen
(virtual protected member function) |
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[virtual]
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attempts to replace the controlled character sequence with an array
(virtual protected member function) |
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[virtual]
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repositions the next pointer in the input sequence, output sequence, or both, using relative addressing
(virtual protected member function) |
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[virtual]
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repositions the next pointer in the input sequence, output sequence, or both using absolute addressing
(virtual protected member function) |
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
.
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int_type
|
Traits::int_type
|
pos_type
|
Traits::pos_type
|
off_type
|
Traits::off_type
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Member functions
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[virtual]
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destructs the
basic_streambuf
object
(virtual public member function of
std::basic_streambuf<CharT,Traits>
)
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Locales |
|
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invokes
imbue
(
)
(public member function of
std::basic_streambuf<CharT,Traits>
)
|
|
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obtains a copy of the associated locale
(public member function of
std::basic_streambuf<CharT,Traits>
)
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Positioning |
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invokes
setbuf
(
)
(public member function of
std::basic_streambuf<CharT,Traits>
)
|
|
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invokes
seekoff
(
)
(public member function of
std::basic_streambuf<CharT,Traits>
)
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invokes
seekpos
(
)
(public member function of
std::basic_streambuf<CharT,Traits>
)
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invokes
sync
(
)
(public member function of
std::basic_streambuf<CharT,Traits>
)
|
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Get area |
|
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obtains the number of characters immediately available in the get area
(public member function of
std::basic_streambuf<CharT,Traits>
)
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advances the input sequence, then reads one character without advancing again
(public member function of
std::basic_streambuf<CharT,Traits>
)
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(removed in C++17)
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reads one character from the input sequence and advances the sequence
(public member function of
std::basic_streambuf<CharT,Traits>
)
|
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reads one character from the input sequence without advancing the sequence
(public member function of
std::basic_streambuf<CharT,Traits>
)
|
|
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invokes
xsgetn
(
)
(public member function of
std::basic_streambuf<CharT,Traits>
)
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Put area |
|
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writes one character to the put area and advances the next pointer
(public member function of
std::basic_streambuf<CharT,Traits>
)
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invokes
xsputn
(
)
(public member function of
std::basic_streambuf<CharT,Traits>
)
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Putback |
|
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puts one character back in the input sequence
(public member function of
std::basic_streambuf<CharT,Traits>
)
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moves the next pointer in the input sequence back by one
(public member function of
std::basic_streambuf<CharT,Traits>
)
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Protected member functions
constructs a
basic_streambuf
object
(protected member function) |
|
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(C++11)
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replaces a
basic_streambuf
object
(protected member function) |
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(C++11)
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swaps two
basic_streambuf
objects
(protected member function) |
Locales |
|
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[virtual]
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changes the associated locale
(virtual protected member function of
std::basic_streambuf<CharT,Traits>
)
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Positioning |
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[virtual]
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replaces the buffer with user-defined array, if permitted
(virtual protected member function of
std::basic_streambuf<CharT,Traits>
)
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[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>
)
|
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[virtual]
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synchronizes the buffers with the associated character sequence
(virtual protected member function of
std::basic_streambuf<CharT,Traits>
)
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Get area |
|
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[virtual]
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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>
)
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[virtual]
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reads characters from the associated input sequence to the get area
(virtual protected member function of
std::basic_streambuf<CharT,Traits>
)
|
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[virtual]
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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>
)
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[virtual]
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reads multiple characters from the input sequence
(virtual protected member function of
std::basic_streambuf<CharT,Traits>
)
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returns a pointer to the beginning, current character and the end of the get area
(protected member function) |
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advances the next pointer in the input sequence
(protected member function) |
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repositions the beginning, next, and end pointers of the input sequence
(protected member function) |
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Put area |
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[virtual]
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writes multiple characters to the output sequence
(virtual protected member function of
std::basic_streambuf<CharT,Traits>
)
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[virtual]
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writes characters to the associated output sequence from the put area
(virtual protected member function of
std::basic_streambuf<CharT,Traits>
)
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returns a pointer to the beginning, current character and the end of the put area
(protected member function) |
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advances the next pointer of the output sequence
(protected member function) |
|
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repositions the beginning, next, and end pointers of the output sequence
(protected member function) |
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Putback |
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[virtual]
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puts a character back into the input sequence, possibly modifying the input sequence
(virtual protected member function of
std::basic_streambuf<CharT,Traits>
)
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