From cppreference.com
int_typesnextc();Advances the input sequence by one character and reads one character.
The function calls
to advance the input sequence. If that function returns Traits::eof() meaning that input sequence has been exhausted and
could not retrieve more data, Traits::eof() is returned. Otherwise
is called in order to read the character.
Parameters
(none)
Return value
The value of the next character. If the input sequence has been exhausted, Traits::eof() is returned.
Example
See also
reads one character from the input sequence without advancing the sequence
(public member function)
(removed in C++17)
reads one character from the input sequence and advances the sequence
(public member function)