std::istreambuf_iterator::istreambuf_iterator
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                    < cpp | iterator | istreambuf iterator
                    
                                                            
                    |   constexpr istreambuf_iterator();  | 
(1) | |
|   istreambuf_iterator( std::basic_istream<CharT,Traits>& is );  | 
(2) | |
|   istreambuf_iterator( std::basic_streambuf<CharT,Traits>* s );  | 
(3) | |
1) Constructs the end-of-stream iterator.
2) Initializes the iterator and stores the address of is.rdbuf() in a data member. If is.rdbuf() is null, then end-of-stream iterator is constructed. 
3) Initializes the iterator and stores the address of 
s in a data member.[edit] Parameters
| is | - | stream to obtain the stream buffer from | 
| s | - | stream buffer to initialize the iterator with | 
[edit] Exceptions
1-4)