mirror of https://github.com/CGAL/cgal
112 lines
2.5 KiB
C++
112 lines
2.5 KiB
C++
// Copyright (c) 1997
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// Utrecht University (The Netherlands),
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// ETH Zurich (Switzerland),
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// INRIA Sophia-Antipolis (France),
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// Max-Planck-Institute Saarbruecken (Germany),
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// and Tel-Aviv University (Israel). All rights reserved.
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//
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// This file is part of CGAL (www.cgal.org)
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//
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// $URL$
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// $Id$
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// SPDX-License-Identifier: LGPL-3.0-or-later OR LicenseRef-Commercial
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//
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//
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// Author(s) : Lutz Kettner <kettner@inf.ethz.ch>
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#ifndef CGAL_IO_ISTREAM_ITERATOR_H
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#define CGAL_IO_ISTREAM_ITERATOR_H
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#include <CGAL/circulator.h>
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namespace CGAL {
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/*!
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\ingroup PkgStreamSupportRef
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The class `Istream_iterator` is an input iterator adaptor for the
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input stream class `Stream` and value type `T`. It is particularly
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useful for classes that are similar but not compatible to `std::istream`.
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\cgalModels{InputIterator}
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*/
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template <class T, class Stream>
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class Istream_iterator
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{
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protected:
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Stream* stream;
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T value;
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void read()
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{
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if(stream)
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{
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if(*stream)
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{
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*stream >> value;
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if(! *stream)
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stream = 0;
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}
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else
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{
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stream = 0;
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}
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}
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}
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public:
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typedef T value_type;
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typedef const T& reference;
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typedef const T& const_reference;
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typedef const T* pointer;
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typedef const T* const_pointer;
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typedef std::size_t size_type;
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typedef std::ptrdiff_t difference_type;
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typedef std::input_iterator_tag iterator_category;
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typedef Istream_iterator<T,Stream> Self;
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/// \name Creation
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/// @{
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/*!
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creates an end-of-stream iterator.
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This is a past-the-end iterator, and it is useful
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when constructing a range.
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*/
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Istream_iterator() : stream(0) {}
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/*!
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creates an input iterator reading from `s`.
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When `s` reaches end of stream,
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this iterator will compare equal to an end-of-stream iterator
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created using the default constructor.
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*/
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Istream_iterator(Stream& s) : stream(&s) { read(); }
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/// @}
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bool operator==( const Self& i) const { return stream == i.stream; }
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bool operator!=( const Self& i) const { return stream != i.stream; }
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reference operator*() const { return value; }
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#ifdef CGAL_ARROW_OPERATOR
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pointer operator->() const { return &(operator*()); }
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#endif
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Self& operator++()
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{
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read();
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return *this;
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}
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Self operator++(int)
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{
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Self tmp = *this;
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read();
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return tmp;
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}
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};
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} // namespace CGAL
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#endif // CGAL_IO_ISTREAM_ITERATOR_H
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