25 Iterators library [iterators]

25.6 Stream iterators [stream.iterators]

25.6.4 Class template istreambuf_­iterator [istreambuf.iterator]

25.6.4.2 Class istreambuf_­iterator​::​proxy [istreambuf.iterator.proxy]

Class istreambuf_­iterator<charT,traits>​::​proxy is for exposition only.
An implementation is permitted to provide equivalent functionality without providing a class with this name.
Class istreambuf_­iterator<charT, traits>​::​proxy provides a temporary placeholder as the return value of the post-increment operator (operator++).
It keeps the character pointed to by the previous value of the iterator for some possible future access to get the character.
namespace std { template<class charT, class traits> class istreambuf_iterator<charT, traits>::proxy { // exposition only charT keep_; basic_streambuf<charT,traits>* sbuf_; proxy(charT c, basic_streambuf<charT,traits>* sbuf) : keep_(c), sbuf_(sbuf) { } public: charT operator*() { return keep_; } }; }