std::char_traits::not_eof - std::char_traits::not_eof
static int_type not_eof( int_type e ); (until C++11)
static constexpr int_type not_eof( int_type e ) noexcept; (since
C++11)
Given e, produce a suitable value that is not equivalent to eof.
Formally
* if X::eq_int_type(e, X::eof()) is false, returns e
* otherwise, returns a value f such that X::eq_int_type(f, X::eof()) is
false
This function is typically used when a value other than eof needs to be
returned,
such as in implementations of std::basic_streambuf::overflow().
e if e and eof value are not equivalent, returns some other
non-eof value otherwise.
eof returns an eof value
[static] (public static member function)