I/O manipulators | ||||
Print functions(C++23) | ||||
C-style I/O | ||||
Buffers | ||||
(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) |
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protected: virtual int_type uflow(); | ||
Ensures that at least one character is available in the input area by updating the pointers to the input area (if needed). On success returns the value of that character and advances the value of theget pointer by one character. On failure returnstraits::eof().
The function may updategptr
,egptr
andeback
pointers to define the location of newly loaded data (if any). On failure, the function ensures that eithergptr()== nullptr orgptr()== egptr.
The base class version of the function callsunderflow() and incrementsgptr().
Contents |
(none)
The value of the character that was pointed to by theget pointer before it was advanced by one, ortraits::eof() otherwise.
The base class version of the function returns the value returned byunderflow().
The public functions ofstd::streambuf call this function only ifgptr()== nullptr orgptr()>= egptr().
The custom streambuf classes that do not use the get area and do not set the get area pointers in basic_streambuf are required to override this function.
This section is incomplete Reason: no example |
[virtual] | reads characters from the associated input sequence to the get area (virtual protected member function)[edit] |
[virtual] | writes characters to the associated output sequence from the put area (virtual protected member function)[edit] |