C++ named requirements: UnformattedOutputFunction - cppreference.com (original) (raw)

[edit] Requirements

A UnformattedOutputFunction is a stream output function that performs the following:

1. Constructs an object of type

basic_ostream::sentry

with automatic storage duration, which performs the following:

• If eofbit or badbit are set on the output stream, sets the failbit as well, and if exceptions on failbit are enabled in this output stream's exception mask ((exceptions() & failbit) != 0), throws ios_base::failure.
• Flushes the tie()'d output stream, if applicable.

1. Checks the status of the sentry by calling sentry::operator bool(), which is equivalent to

basic_ios::good

.

• If the operator returns false or sentry's constructor throws an exception, no output takes place.

• If the operator returns true, attempts to perform the desired output by inserting the characters into the output stream as if by calling rdbuf()->sputc(). Other public members of std::basic_ostream may also be used, but virtual members of rdbuf() except overflow(), xsputn() and sync() will never be called.

• If an exception is thrown during output, sets badbit in the output stream. If exceptions on badbit are enabled in this stream's exception mask ((exceptions() & badbit) != 0), the exception is also rethrown.

• If no exception was thrown, returns the value specified by the function.

1. In any event, whether terminating by exception or returning, the sentry's destructor is called before leaving this function.

[edit] Standard library

The following standard library functions are UnformattedOutputFunctions.

• basic_ostream::operator<<(basic_streambuf*)
• basic_ostream::put
• basic_ostream::write
• basic_ostream::flush

[edit] Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.