[istream.formatted.arithmetic] (original) (raw)

As in the case of the inserters, these extractors depend on the locale'snum_get<> object to perform parsing the input stream data.

After a sentry object is constructed, the conversion occurs as if performed by the following code fragment, where state represents the input function's local error state:using numget = num_get<charT, istreambuf_iterator<charT, traits>>; use_facet<numget>(loc).get(*this, 0, *this, state, val);

In the above fragment,locstands for the private member of thebasic_iosclass.

[Note 1:

The first argument provides an object of theistreambuf_iteratorclass which is an iterator pointed to an input stream.

It bypasses istreams and uses streambufs directly.

— _end note_]

Classlocalerelies on this type as its interface toistream, so that it does not need to depend directly onistream.