C++ named requirements: FormattedInputFunction

 

C++

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Named requirements

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Concepts library (C++20)

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Regular expressions library (C++11)

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Technical Specifications

 

C++ named requirements

Basic
DefaultConstructible CopyAssignable CopyConstructible	MoveAssignable (C++11) MoveConstructible (C++11) Destructible
Layout
TrivialType (C++11) TriviallyCopyable (C++11)	StandardLayoutType (C++11) PODType
Library-Wide
EqualityComparable LessThanComparable Swappable (C++11) ValueSwappable (C++11) NullablePointer (C++11) Hash (C++11)	Allocator FunctionObject Callable Predicate BinaryPredicate Compare
Container
Container SequenceContainer ContiguousContainer (C++17) ReversibleContainer	AssociativeContainer AllocatorAwareContainer UnorderedAssociativeContainer (C++11)
Container Elements
DefaultInsertable (C++11) CopyInsertable (C++11) MoveInsertable (C++11)	EmplaceConstructible (C++11) Erasable (C++11)
Iterator
LegacyIterator LegacyOutputIterator LegacyInputIterator LegacyForwardIterator	LegacyBidirectionalIterator LegacyRandomAccessIterator LegacyContiguousIterator (C++17) ConstexprIterator (C++20)
Stream I/O
FormattedInputFunction UnformattedInputFunction	FormattedOutputFunction UnformattedOutputFunction
Random Numbers
SeedSequence (C++11) RandomNumberEngine (C++11)	RandomNumberDistribution (C++11) UniformRandomBitGenerator (C++11) RandomNumberEngineAdaptor (C++11)
Concurrency
BasicLockable (C++11) Lockable (C++11) TimedLockable (C++11)	Mutex (C++11) TimedMutex (C++11) SharedMutex (C++17) SharedTimedMutex (C++14)
Other
CharTraits RegexTraits (C++11) BitmaskType NumericType LiteralType (C++11)	UnaryTypeTrait (C++11) BinaryTypeTrait (C++11) TransformationTrait (C++11) Clock (C++11) TrivialClock (C++11)

 

Requirements

A FormattedInputFunction 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 false, 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 ios_base::skipws flag is set on this input stream, extracts and discards characters from the input stream until one of the following becomes true:

• the next available character on the input stream is not a whitespace character, as tested by the std::ctype facet of the locale currently imbued in this input stream. The non-whitespace character is not extracted.
• the end of the stream is reached, in which case failbit and eofbit are set and if the stream is on for exceptions on one of these bits, ios_base::failure is thrown.

• 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, no input takes place
• 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, returns *this.

• 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 FormattedInputFunctions.

• basic_istream::operator>>(int, long, double, void*, bool)
• operator>>(std::basic_istream, char&)
• operator>>(std::basic_istream, char*)
• operator>>(std::basic_istream, std::bitset)
• operator>>(std::basic_istream, std::string)
• operator>>, when called on the return value of std::get_money