std::basic_filebuf::pbackfail
| protected: virtual int_type pbackfail( int_type c = Traits::eof() ) |
||
Puts the character c back into the get area, in one of the three ways:
1) If c is not the EOF character, as determined by calling Traits::eq_int_type(c,traits::eof()) and if there is room for a putback, and if c is exactly the character that was most recently read from the get area, as determined by Traits::eq(to_char_type(c),gptr()[-1]), then simply decrements gptr() by one.
2) If c is not the EOF character, as determined by calling Traits::eq_int_type(c,traits::eof()) and if there is room for a putback, and if the buffer is allowed to modify the get area, decrements gptr() and writes c to there. Note that this does not modify the associated character sequence (the file), but only the get area in memory.
3) If c is the EOF character (Traits::eq_int_type(c,traits::eof()) returns true), and if there is room for a putback, decrements gptr(). This has the effect of making the last character read available for reading once again.
If the file is not open (is_open()==false, this function returns Traits::eof() immediately.
Contents |
[edit] Parameters
| c | - | the character to putback, or eof |
[edit] Return value
1-2) c
3) Traits::not_eof(c)
Traits::eof() in case of failure.
[edit] Example
| This section is incomplete Reason: no example |
[edit] See also
| [virtual] |
puts a character back into the input sequence, possibly modifying the input sequence (virtual protected member function of std::basic_streambuf) |
| moves the next pointer in the input sequence back by one (public member function of std::basic_streambuf) | |
| puts one character back in the input sequence (public member function of std::basic_streambuf) | |
| unextracts a character (public member function of std::basic_istream) | |
| puts character into input stream (public member function of std::basic_istream) | |
