C++ concepts: UnformattedInputFunction
From cppreference.com
Requirements
An UnformattedInputFunction
is a stream input function that performs the following:
- Constructs an object of type basic_istream::sentry with automatic storage duration and with the
noskipws
argument set to true, which performs the following
- if eofbit or badbit are set on the input stream, sets the
failbit
as well, and if exceptions on failbit are enabled in this input stream's exception mask, throws ios_base::failure. - flushes the tie()'d output stream, if applicable
- if eofbit or badbit are set on the input stream, sets the
- Checks the status of the sentry by calling
sentry::operator bool()
, which is equivalent to basic_ios::good. - If the sentry returned false or sentry's constructor threw an exception:
- sets the number of extracted characters (gcount) in the input stream to zero
- if the function was called to write to an array of
CharT
, writesCharT()
(the null character) to the first location of the array
- If the sentry returned true, performs the input as if by calling rdbuf()->sbumpc() or rdbuf()->sgetc().
- if the end of the stream is reached (the call to rdbuf()->sbumpc() or rdbuf()->sgetc() returns Traits::eof(), sets
eofbit
. If exceptions on eofbit are enabled in this stream's exception mask, throws ios_base::failure. - if an exception is thrown during input, sets
badbit
in the input stream. If exceptions on badbit are enabled in this stream's exception mask, the exception is also rethrown. - If no exception was thrown during input, sets the number of extracted characters (gcount) in the input stream.
- if the end of the stream is reached (the call to rdbuf()->sbumpc() or rdbuf()->sgetc() returns Traits::eof(), sets
- In any event, whether terminating by exception or returning, the sentry's destructor is called before leaving this function.
Standard library
The following standard library functions are UnformattedInputFunction
s.
- std::getline, except that it does not modify gcount.
- basic_istream::operator>>(basic_streambuf*)
- basic_istream::get
- basic_istream::getline
- basic_istream::ignore
- basic_istream::peek
- basic_istream::read
- basic_istream::readsome
- basic_istream::putback, except that it first clears
eofbit
- basic_istream::unget, except that it first clears
eofbit
- basic_istream::sync, except that it does not modify gcount
- basic_istream::tellg, except that it does not modify gcount
- basic_istream::seekg, except that it first clears
eofbit
and does not modify gcount - std::ws, except that it does not modify gcount