29 Input/output library [input.output]

29.7 Formatting and manipulators [iostream.format]

29.7.4 Input streams [input.streams]

29.7.4.3 Formatted input functions [istream.formatted]

29.7.4.3.2 Arithmetic extractors [istream.formatted.arithmetic]

basic_istream& operator>>(unsigned short& val); basic_istream& operator>>(unsigned int& val); basic_istream& operator>>(long& val); basic_istream& operator>>(unsigned long& val); basic_istream& operator>>(long long& val); basic_istream& operator>>(unsigned long long& val); basic_istream& operator>>(float& val); basic_istream& operator>>(double& val); basic_istream& operator>>(long double& val); basic_istream& operator>>(bool& val); basic_istream& operator>>(void*& val);
As in the case of the inserters, these extractors depend on the locale's num_­get<> object to perform parsing the input stream data.
These extractors behave as formatted input functions (as described in [istream.formatted.reqmts]).
After a sentry object is constructed, the conversion occurs as if performed by the following code fragment: using numget = num_get<charT, istreambuf_iterator<charT, traits>>; iostate err = iostate::goodbit; use_facet<numget>(loc).get(*this, 0, *this, err, val); setstate(err);
In the above fragment, loc stands for the private member of the basic_­ios class.
[Note 1:
The first argument provides an object of the istreambuf_­iterator class which is an iterator pointed to an input stream.
It bypasses istreams and uses streambufs directly.
— end note]
Class locale relies on this type as its interface to istream, so that it does not need to depend directly on istream.
basic_istream& operator>>(short& val);
The conversion occurs as if performed by the following code fragment (using the same notation as for the preceding code fragment): using numget = num_get<charT, istreambuf_iterator<charT, traits>>; iostate err = ios_base::goodbit; long lval; use_facet<numget>(loc).get(*this, 0, *this, err, lval); if (lval < numeric_limits<short>::min()) { err |= ios_base::failbit; val = numeric_limits<short>::min(); } else if (numeric_limits<short>::max() < lval) { err |= ios_base::failbit; val = numeric_limits<short>::max(); } else val = static_cast<short>(lval); setstate(err);
basic_istream& operator>>(int& val);
The conversion occurs as if performed by the following code fragment (using the same notation as for the preceding code fragment): using numget = num_get<charT, istreambuf_iterator<charT, traits>>; iostate err = ios_base::goodbit; long lval; use_facet<numget>(loc).get(*this, 0, *this, err, lval); if (lval < numeric_limits<int>::min()) { err |= ios_base::failbit; val = numeric_limits<int>::min(); } else if (numeric_limits<int>::max() < lval) { err |= ios_base::failbit; val = numeric_limits<int>::max(); } else val = static_cast<int>(lval); setstate(err);