Input Stream Buffer Iterators
Table 15.46 lists all operations of input stream buffer iterators. The implementation is similar to that
for istream iterators (see Section 9.4.3, page 462). In addition, you can initialize the iterator with a
buffer, and member function equal() is provided, which returns whether two input stream buffer
iterators are equal. Two input stream buffer iterators are equal when they are both end-of-stream
iterators or when neither is an end-of-stream iterator.