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863 lines
24 KiB
863 lines
24 KiB
4 years ago
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/*
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*
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* Copyright (c) 2004
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* John Maddock
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*
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* Use, modification and distribution are subject to the
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* Boost Software License, Version 1.0. (See accompanying file
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* LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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*
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*/
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/*
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* LOCATION: see http://www.boost.org for most recent version.
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* FILE unicode_iterator.hpp
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* VERSION see <boost/version.hpp>
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* DESCRIPTION: Iterator adapters for converting between different Unicode encodings.
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*/
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/****************************************************************************
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Contents:
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~~~~~~~~~
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1) Read Only, Input Adapters:
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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template <class BaseIterator, class U8Type = std::uint8_t>
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class u32_to_u8_iterator;
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Adapts sequence of UTF-32 code points to "look like" a sequence of UTF-8.
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template <class BaseIterator, class U32Type = std::uint32_t>
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class u8_to_u32_iterator;
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Adapts sequence of UTF-8 code points to "look like" a sequence of UTF-32.
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template <class BaseIterator, class U16Type = std::uint16_t>
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class u32_to_u16_iterator;
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Adapts sequence of UTF-32 code points to "look like" a sequence of UTF-16.
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template <class BaseIterator, class U32Type = std::uint32_t>
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class u16_to_u32_iterator;
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Adapts sequence of UTF-16 code points to "look like" a sequence of UTF-32.
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2) Single pass output iterator adapters:
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template <class BaseIterator>
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class utf8_output_iterator;
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Accepts UTF-32 code points and forwards them on as UTF-8 code points.
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template <class BaseIterator>
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class utf16_output_iterator;
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Accepts UTF-32 code points and forwards them on as UTF-16 code points.
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****************************************************************************/
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#ifndef BOOST_REGEX_UNICODE_ITERATOR_HPP
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#define BOOST_REGEX_UNICODE_ITERATOR_HPP
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#include <cstdint>
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#include <boost/regex/config.hpp>
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#include <stdexcept>
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#include <sstream>
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#include <ios>
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#include <limits.h> // CHAR_BIT
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#ifndef BOOST_REGEX_STANDALONE
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#include <boost/throw_exception.hpp>
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#endif
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namespace boost{
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namespace detail{
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static const std::uint16_t high_surrogate_base = 0xD7C0u;
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static const std::uint16_t low_surrogate_base = 0xDC00u;
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static const std::uint32_t ten_bit_mask = 0x3FFu;
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inline bool is_high_surrogate(std::uint16_t v)
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{
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return (v & 0xFFFFFC00u) == 0xd800u;
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}
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inline bool is_low_surrogate(std::uint16_t v)
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{
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return (v & 0xFFFFFC00u) == 0xdc00u;
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}
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template <class T>
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inline bool is_surrogate(T v)
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{
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return (v & 0xFFFFF800u) == 0xd800;
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}
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inline unsigned utf8_byte_count(std::uint8_t c)
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{
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// if the most significant bit with a zero in it is in position
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// 8-N then there are N bytes in this UTF-8 sequence:
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std::uint8_t mask = 0x80u;
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unsigned result = 0;
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while(c & mask)
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{
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++result;
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mask >>= 1;
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}
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return (result == 0) ? 1 : ((result > 4) ? 4 : result);
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}
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inline unsigned utf8_trailing_byte_count(std::uint8_t c)
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{
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return utf8_byte_count(c) - 1;
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}
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#ifdef BOOST_REGEX_MSVC
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#pragma warning(push)
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#pragma warning(disable:4100)
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#endif
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#ifndef BOOST_NO_EXCEPTIONS
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BOOST_REGEX_NORETURN
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#endif
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inline void invalid_utf32_code_point(std::uint32_t val)
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{
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std::stringstream ss;
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ss << "Invalid UTF-32 code point U+" << std::showbase << std::hex << val << " encountered while trying to encode UTF-16 sequence";
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std::out_of_range e(ss.str());
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#ifndef BOOST_REGEX_STANDALONE
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boost::throw_exception(e);
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#else
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throw e;
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#endif
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}
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#ifdef BOOST_REGEX_MSVC
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#pragma warning(pop)
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#endif
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} // namespace detail
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template <class BaseIterator, class U16Type = std::uint16_t>
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class u32_to_u16_iterator
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{
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typedef typename std::iterator_traits<BaseIterator>::value_type base_value_type;
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static_assert(sizeof(base_value_type)*CHAR_BIT == 32, "Incorrectly sized template argument");
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static_assert(sizeof(U16Type)*CHAR_BIT == 16, "Incorrectly sized template argument");
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public:
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typedef std::ptrdiff_t difference_type;
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typedef U16Type value_type;
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typedef value_type const* pointer;
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typedef value_type const reference;
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typedef std::bidirectional_iterator_tag iterator_category;
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reference operator*()const
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{
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if(m_current == 2)
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extract_current();
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return m_values[m_current];
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}
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bool operator==(const u32_to_u16_iterator& that)const
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{
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if(m_position == that.m_position)
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{
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// Both m_currents must be equal, or both even
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// this is the same as saying their sum must be even:
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return (m_current + that.m_current) & 1u ? false : true;
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}
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return false;
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}
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bool operator!=(const u32_to_u16_iterator& that)const
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{
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return !(*this == that);
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}
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u32_to_u16_iterator& operator++()
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{
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// if we have a pending read then read now, so that we know whether
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// to skip a position, or move to a low-surrogate:
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if(m_current == 2)
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{
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// pending read:
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extract_current();
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}
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// move to the next surrogate position:
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++m_current;
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// if we've reached the end skip a position:
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if(m_values[m_current] == 0)
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{
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m_current = 2;
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++m_position;
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}
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return *this;
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}
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u32_to_u16_iterator operator++(int)
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{
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u32_to_u16_iterator r(*this);
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++(*this);
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return r;
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}
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u32_to_u16_iterator& operator--()
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{
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if(m_current != 1)
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{
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// decrementing an iterator always leads to a valid position:
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--m_position;
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extract_current();
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m_current = m_values[1] ? 1 : 0;
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}
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else
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{
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m_current = 0;
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}
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return *this;
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}
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u32_to_u16_iterator operator--(int)
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{
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u32_to_u16_iterator r(*this);
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--(*this);
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return r;
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}
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BaseIterator base()const
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{
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return m_position;
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}
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// construct:
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u32_to_u16_iterator() : m_position(), m_current(0)
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{
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m_values[0] = 0;
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m_values[1] = 0;
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m_values[2] = 0;
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}
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u32_to_u16_iterator(BaseIterator b) : m_position(b), m_current(2)
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{
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m_values[0] = 0;
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m_values[1] = 0;
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m_values[2] = 0;
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}
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private:
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void extract_current()const
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{
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// begin by checking for a code point out of range:
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std::uint32_t v = *m_position;
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if(v >= 0x10000u)
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{
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if(v > 0x10FFFFu)
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detail::invalid_utf32_code_point(*m_position);
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// split into two surrogates:
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m_values[0] = static_cast<U16Type>(v >> 10) + detail::high_surrogate_base;
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m_values[1] = static_cast<U16Type>(v & detail::ten_bit_mask) + detail::low_surrogate_base;
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m_current = 0;
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BOOST_REGEX_ASSERT(detail::is_high_surrogate(m_values[0]));
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BOOST_REGEX_ASSERT(detail::is_low_surrogate(m_values[1]));
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}
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else
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{
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// 16-bit code point:
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m_values[0] = static_cast<U16Type>(*m_position);
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m_values[1] = 0;
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m_current = 0;
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// value must not be a surrogate:
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if(detail::is_surrogate(m_values[0]))
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detail::invalid_utf32_code_point(*m_position);
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}
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}
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BaseIterator m_position;
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mutable U16Type m_values[3];
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mutable unsigned m_current;
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};
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template <class BaseIterator, class U32Type = std::uint32_t>
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class u16_to_u32_iterator
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{
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// special values for pending iterator reads:
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static const U32Type pending_read = 0xffffffffu;
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typedef typename std::iterator_traits<BaseIterator>::value_type base_value_type;
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static_assert(sizeof(base_value_type)*CHAR_BIT == 16, "Incorrectly sized template argument");
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static_assert(sizeof(U32Type)*CHAR_BIT == 32, "Incorrectly sized template argument");
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public:
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typedef std::ptrdiff_t difference_type;
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typedef U32Type value_type;
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typedef value_type const* pointer;
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typedef value_type const reference;
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typedef std::bidirectional_iterator_tag iterator_category;
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reference operator*()const
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{
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if(m_value == pending_read)
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extract_current();
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return m_value;
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}
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bool operator==(const u16_to_u32_iterator& that)const
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{
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return m_position == that.m_position;
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}
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bool operator!=(const u16_to_u32_iterator& that)const
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{
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return !(*this == that);
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}
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u16_to_u32_iterator& operator++()
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{
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// skip high surrogate first if there is one:
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if(detail::is_high_surrogate(*m_position)) ++m_position;
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++m_position;
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m_value = pending_read;
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return *this;
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}
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u16_to_u32_iterator operator++(int)
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{
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u16_to_u32_iterator r(*this);
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++(*this);
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return r;
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}
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u16_to_u32_iterator& operator--()
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{
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--m_position;
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// if we have a low surrogate then go back one more:
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if(detail::is_low_surrogate(*m_position))
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--m_position;
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m_value = pending_read;
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return *this;
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}
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u16_to_u32_iterator operator--(int)
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{
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u16_to_u32_iterator r(*this);
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--(*this);
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return r;
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}
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BaseIterator base()const
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{
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return m_position;
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}
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// construct:
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u16_to_u32_iterator() : m_position()
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{
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m_value = pending_read;
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}
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u16_to_u32_iterator(BaseIterator b) : m_position(b)
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{
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m_value = pending_read;
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}
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//
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// Range checked version:
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//
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u16_to_u32_iterator(BaseIterator b, BaseIterator start, BaseIterator end) : m_position(b)
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{
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m_value = pending_read;
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//
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// The range must not start with a low surrogate, or end in a high surrogate,
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// otherwise we run the risk of running outside the underlying input range.
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// Likewise b must not be located at a low surrogate.
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//
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std::uint16_t val;
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if(start != end)
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{
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if((b != start) && (b != end))
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{
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val = *b;
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if(detail::is_surrogate(val) && ((val & 0xFC00u) == 0xDC00u))
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invalid_code_point(val);
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}
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val = *start;
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if(detail::is_surrogate(val) && ((val & 0xFC00u) == 0xDC00u))
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invalid_code_point(val);
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val = *--end;
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if(detail::is_high_surrogate(val))
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invalid_code_point(val);
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}
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}
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private:
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static void invalid_code_point(std::uint16_t val)
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{
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std::stringstream ss;
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ss << "Misplaced UTF-16 surrogate U+" << std::showbase << std::hex << val << " encountered while trying to encode UTF-32 sequence";
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std::out_of_range e(ss.str());
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#ifndef BOOST_REGEX_STANDALONE
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boost::throw_exception(e);
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#else
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throw e;
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#endif
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}
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void extract_current()const
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{
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m_value = static_cast<U32Type>(static_cast< std::uint16_t>(*m_position));
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// if the last value is a high surrogate then adjust m_position and m_value as needed:
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if(detail::is_high_surrogate(*m_position))
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{
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// precondition; next value must have be a low-surrogate:
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BaseIterator next(m_position);
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std::uint16_t t = *++next;
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if((t & 0xFC00u) != 0xDC00u)
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invalid_code_point(t);
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m_value = (m_value - detail::high_surrogate_base) << 10;
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m_value |= (static_cast<U32Type>(static_cast< std::uint16_t>(t)) & detail::ten_bit_mask);
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}
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// postcondition; result must not be a surrogate:
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if(detail::is_surrogate(m_value))
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invalid_code_point(static_cast< std::uint16_t>(m_value));
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}
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BaseIterator m_position;
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mutable U32Type m_value;
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};
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template <class BaseIterator, class U8Type = std::uint8_t>
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class u32_to_u8_iterator
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{
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typedef typename std::iterator_traits<BaseIterator>::value_type base_value_type;
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static_assert(sizeof(base_value_type)*CHAR_BIT == 32, "Incorrectly sized template argument");
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static_assert(sizeof(U8Type)*CHAR_BIT == 8, "Incorrectly sized template argument");
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public:
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typedef std::ptrdiff_t difference_type;
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typedef U8Type value_type;
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typedef value_type const* pointer;
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typedef value_type const reference;
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typedef std::bidirectional_iterator_tag iterator_category;
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reference operator*()const
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{
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if(m_current == 4)
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extract_current();
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return m_values[m_current];
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}
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bool operator==(const u32_to_u8_iterator& that)const
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{
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if(m_position == that.m_position)
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{
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// either the m_current's must be equal, or one must be 0 and
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// the other 4: which means neither must have bits 1 or 2 set:
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return (m_current == that.m_current)
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|| (((m_current | that.m_current) & 3) == 0);
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}
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return false;
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}
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bool operator!=(const u32_to_u8_iterator& that)const
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{
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||
|
return !(*this == that);
|
||
|
}
|
||
|
u32_to_u8_iterator& operator++()
|
||
|
{
|
||
|
// if we have a pending read then read now, so that we know whether
|
||
|
// to skip a position, or move to a low-surrogate:
|
||
|
if(m_current == 4)
|
||
|
{
|
||
|
// pending read:
|
||
|
extract_current();
|
||
|
}
|
||
|
// move to the next surrogate position:
|
||
|
++m_current;
|
||
|
// if we've reached the end skip a position:
|
||
|
if(m_values[m_current] == 0)
|
||
|
{
|
||
|
m_current = 4;
|
||
|
++m_position;
|
||
|
}
|
||
|
return *this;
|
||
|
}
|
||
|
u32_to_u8_iterator operator++(int)
|
||
|
{
|
||
|
u32_to_u8_iterator r(*this);
|
||
|
++(*this);
|
||
|
return r;
|
||
|
}
|
||
|
u32_to_u8_iterator& operator--()
|
||
|
{
|
||
|
if((m_current & 3) == 0)
|
||
|
{
|
||
|
--m_position;
|
||
|
extract_current();
|
||
|
m_current = 3;
|
||
|
while(m_current && (m_values[m_current] == 0))
|
||
|
--m_current;
|
||
|
}
|
||
|
else
|
||
|
--m_current;
|
||
|
return *this;
|
||
|
}
|
||
|
u32_to_u8_iterator operator--(int)
|
||
|
{
|
||
|
u32_to_u8_iterator r(*this);
|
||
|
--(*this);
|
||
|
return r;
|
||
|
}
|
||
|
BaseIterator base()const
|
||
|
{
|
||
|
return m_position;
|
||
|
}
|
||
|
// construct:
|
||
|
u32_to_u8_iterator() : m_position(), m_current(0)
|
||
|
{
|
||
|
m_values[0] = 0;
|
||
|
m_values[1] = 0;
|
||
|
m_values[2] = 0;
|
||
|
m_values[3] = 0;
|
||
|
m_values[4] = 0;
|
||
|
}
|
||
|
u32_to_u8_iterator(BaseIterator b) : m_position(b), m_current(4)
|
||
|
{
|
||
|
m_values[0] = 0;
|
||
|
m_values[1] = 0;
|
||
|
m_values[2] = 0;
|
||
|
m_values[3] = 0;
|
||
|
m_values[4] = 0;
|
||
|
}
|
||
|
private:
|
||
|
|
||
|
void extract_current()const
|
||
|
{
|
||
|
std::uint32_t c = *m_position;
|
||
|
if(c > 0x10FFFFu)
|
||
|
detail::invalid_utf32_code_point(c);
|
||
|
if(c < 0x80u)
|
||
|
{
|
||
|
m_values[0] = static_cast<unsigned char>(c);
|
||
|
m_values[1] = static_cast<unsigned char>(0u);
|
||
|
m_values[2] = static_cast<unsigned char>(0u);
|
||
|
m_values[3] = static_cast<unsigned char>(0u);
|
||
|
}
|
||
|
else if(c < 0x800u)
|
||
|
{
|
||
|
m_values[0] = static_cast<unsigned char>(0xC0u + (c >> 6));
|
||
|
m_values[1] = static_cast<unsigned char>(0x80u + (c & 0x3Fu));
|
||
|
m_values[2] = static_cast<unsigned char>(0u);
|
||
|
m_values[3] = static_cast<unsigned char>(0u);
|
||
|
}
|
||
|
else if(c < 0x10000u)
|
||
|
{
|
||
|
m_values[0] = static_cast<unsigned char>(0xE0u + (c >> 12));
|
||
|
m_values[1] = static_cast<unsigned char>(0x80u + ((c >> 6) & 0x3Fu));
|
||
|
m_values[2] = static_cast<unsigned char>(0x80u + (c & 0x3Fu));
|
||
|
m_values[3] = static_cast<unsigned char>(0u);
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
m_values[0] = static_cast<unsigned char>(0xF0u + (c >> 18));
|
||
|
m_values[1] = static_cast<unsigned char>(0x80u + ((c >> 12) & 0x3Fu));
|
||
|
m_values[2] = static_cast<unsigned char>(0x80u + ((c >> 6) & 0x3Fu));
|
||
|
m_values[3] = static_cast<unsigned char>(0x80u + (c & 0x3Fu));
|
||
|
}
|
||
|
m_current= 0;
|
||
|
}
|
||
|
BaseIterator m_position;
|
||
|
mutable U8Type m_values[5];
|
||
|
mutable unsigned m_current;
|
||
|
};
|
||
|
|
||
|
template <class BaseIterator, class U32Type = std::uint32_t>
|
||
|
class u8_to_u32_iterator
|
||
|
{
|
||
|
// special values for pending iterator reads:
|
||
|
static const U32Type pending_read = 0xffffffffu;
|
||
|
|
||
|
typedef typename std::iterator_traits<BaseIterator>::value_type base_value_type;
|
||
|
|
||
|
static_assert(sizeof(base_value_type)*CHAR_BIT == 8, "Incorrectly sized template argument");
|
||
|
static_assert(sizeof(U32Type)*CHAR_BIT == 32, "Incorrectly sized template argument");
|
||
|
|
||
|
public:
|
||
|
typedef std::ptrdiff_t difference_type;
|
||
|
typedef U32Type value_type;
|
||
|
typedef value_type const* pointer;
|
||
|
typedef value_type const reference;
|
||
|
typedef std::bidirectional_iterator_tag iterator_category;
|
||
|
|
||
|
reference operator*()const
|
||
|
{
|
||
|
if(m_value == pending_read)
|
||
|
extract_current();
|
||
|
return m_value;
|
||
|
}
|
||
|
bool operator==(const u8_to_u32_iterator& that)const
|
||
|
{
|
||
|
return m_position == that.m_position;
|
||
|
}
|
||
|
bool operator!=(const u8_to_u32_iterator& that)const
|
||
|
{
|
||
|
return !(*this == that);
|
||
|
}
|
||
|
u8_to_u32_iterator& operator++()
|
||
|
{
|
||
|
// We must not start with a continuation character:
|
||
|
if((static_cast<std::uint8_t>(*m_position) & 0xC0) == 0x80)
|
||
|
invalid_sequence();
|
||
|
// skip high surrogate first if there is one:
|
||
|
unsigned c = detail::utf8_byte_count(*m_position);
|
||
|
if(m_value == pending_read)
|
||
|
{
|
||
|
// Since we haven't read in a value, we need to validate the code points:
|
||
|
for(unsigned i = 0; i < c; ++i)
|
||
|
{
|
||
|
++m_position;
|
||
|
// We must have a continuation byte:
|
||
|
if((i != c - 1) && ((static_cast<std::uint8_t>(*m_position) & 0xC0) != 0x80))
|
||
|
invalid_sequence();
|
||
|
}
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
std::advance(m_position, c);
|
||
|
}
|
||
|
m_value = pending_read;
|
||
|
return *this;
|
||
|
}
|
||
|
u8_to_u32_iterator operator++(int)
|
||
|
{
|
||
|
u8_to_u32_iterator r(*this);
|
||
|
++(*this);
|
||
|
return r;
|
||
|
}
|
||
|
u8_to_u32_iterator& operator--()
|
||
|
{
|
||
|
// Keep backtracking until we don't have a trailing character:
|
||
|
unsigned count = 0;
|
||
|
while((*--m_position & 0xC0u) == 0x80u) ++count;
|
||
|
// now check that the sequence was valid:
|
||
|
if(count != detail::utf8_trailing_byte_count(*m_position))
|
||
|
invalid_sequence();
|
||
|
m_value = pending_read;
|
||
|
return *this;
|
||
|
}
|
||
|
u8_to_u32_iterator operator--(int)
|
||
|
{
|
||
|
u8_to_u32_iterator r(*this);
|
||
|
--(*this);
|
||
|
return r;
|
||
|
}
|
||
|
BaseIterator base()const
|
||
|
{
|
||
|
return m_position;
|
||
|
}
|
||
|
// construct:
|
||
|
u8_to_u32_iterator() : m_position()
|
||
|
{
|
||
|
m_value = pending_read;
|
||
|
}
|
||
|
u8_to_u32_iterator(BaseIterator b) : m_position(b)
|
||
|
{
|
||
|
m_value = pending_read;
|
||
|
}
|
||
|
//
|
||
|
// Checked constructor:
|
||
|
//
|
||
|
u8_to_u32_iterator(BaseIterator b, BaseIterator start, BaseIterator end) : m_position(b)
|
||
|
{
|
||
|
m_value = pending_read;
|
||
|
//
|
||
|
// We must not start with a continuation character, or end with a
|
||
|
// truncated UTF-8 sequence otherwise we run the risk of going past
|
||
|
// the start/end of the underlying sequence:
|
||
|
//
|
||
|
if(start != end)
|
||
|
{
|
||
|
unsigned char v = *start;
|
||
|
if((v & 0xC0u) == 0x80u)
|
||
|
invalid_sequence();
|
||
|
if((b != start) && (b != end) && ((*b & 0xC0u) == 0x80u))
|
||
|
invalid_sequence();
|
||
|
BaseIterator pos = end;
|
||
|
do
|
||
|
{
|
||
|
v = *--pos;
|
||
|
}
|
||
|
while((start != pos) && ((v & 0xC0u) == 0x80u));
|
||
|
std::ptrdiff_t extra = detail::utf8_byte_count(v);
|
||
|
if(std::distance(pos, end) < extra)
|
||
|
invalid_sequence();
|
||
|
}
|
||
|
}
|
||
|
private:
|
||
|
static void invalid_sequence()
|
||
|
{
|
||
|
std::out_of_range e("Invalid UTF-8 sequence encountered while trying to encode UTF-32 character");
|
||
|
#ifndef BOOST_REGEX_STANDALONE
|
||
|
boost::throw_exception(e);
|
||
|
#else
|
||
|
throw e;
|
||
|
#endif
|
||
|
}
|
||
|
void extract_current()const
|
||
|
{
|
||
|
m_value = static_cast<U32Type>(static_cast< std::uint8_t>(*m_position));
|
||
|
// we must not have a continuation character:
|
||
|
if((m_value & 0xC0u) == 0x80u)
|
||
|
invalid_sequence();
|
||
|
// see how many extra bytes we have:
|
||
|
unsigned extra = detail::utf8_trailing_byte_count(*m_position);
|
||
|
// extract the extra bits, 6 from each extra byte:
|
||
|
BaseIterator next(m_position);
|
||
|
for(unsigned c = 0; c < extra; ++c)
|
||
|
{
|
||
|
++next;
|
||
|
m_value <<= 6;
|
||
|
// We must have a continuation byte:
|
||
|
if((static_cast<std::uint8_t>(*next) & 0xC0) != 0x80)
|
||
|
invalid_sequence();
|
||
|
m_value += static_cast<std::uint8_t>(*next) & 0x3Fu;
|
||
|
}
|
||
|
// we now need to remove a few of the leftmost bits, but how many depends
|
||
|
// upon how many extra bytes we've extracted:
|
||
|
static const std::uint32_t masks[4] =
|
||
|
{
|
||
|
0x7Fu,
|
||
|
0x7FFu,
|
||
|
0xFFFFu,
|
||
|
0x1FFFFFu,
|
||
|
};
|
||
|
m_value &= masks[extra];
|
||
|
// check the result is in range:
|
||
|
if(m_value > static_cast<U32Type>(0x10FFFFu))
|
||
|
invalid_sequence();
|
||
|
// The result must not be a surrogate:
|
||
|
if((m_value >= static_cast<U32Type>(0xD800)) && (m_value <= static_cast<U32Type>(0xDFFF)))
|
||
|
invalid_sequence();
|
||
|
// We should not have had an invalidly encoded UTF8 sequence:
|
||
|
if((extra > 0) && (m_value <= static_cast<U32Type>(masks[extra - 1])))
|
||
|
invalid_sequence();
|
||
|
}
|
||
|
BaseIterator m_position;
|
||
|
mutable U32Type m_value;
|
||
|
};
|
||
|
|
||
|
template <class BaseIterator>
|
||
|
class utf16_output_iterator
|
||
|
{
|
||
|
public:
|
||
|
typedef void difference_type;
|
||
|
typedef void value_type;
|
||
|
typedef std::uint32_t* pointer;
|
||
|
typedef std::uint32_t& reference;
|
||
|
typedef std::output_iterator_tag iterator_category;
|
||
|
|
||
|
utf16_output_iterator(const BaseIterator& b)
|
||
|
: m_position(b){}
|
||
|
utf16_output_iterator(const utf16_output_iterator& that)
|
||
|
: m_position(that.m_position){}
|
||
|
utf16_output_iterator& operator=(const utf16_output_iterator& that)
|
||
|
{
|
||
|
m_position = that.m_position;
|
||
|
return *this;
|
||
|
}
|
||
|
const utf16_output_iterator& operator*()const
|
||
|
{
|
||
|
return *this;
|
||
|
}
|
||
|
void operator=(std::uint32_t val)const
|
||
|
{
|
||
|
push(val);
|
||
|
}
|
||
|
utf16_output_iterator& operator++()
|
||
|
{
|
||
|
return *this;
|
||
|
}
|
||
|
utf16_output_iterator& operator++(int)
|
||
|
{
|
||
|
return *this;
|
||
|
}
|
||
|
BaseIterator base()const
|
||
|
{
|
||
|
return m_position;
|
||
|
}
|
||
|
private:
|
||
|
void push(std::uint32_t v)const
|
||
|
{
|
||
|
if(v >= 0x10000u)
|
||
|
{
|
||
|
// begin by checking for a code point out of range:
|
||
|
if(v > 0x10FFFFu)
|
||
|
detail::invalid_utf32_code_point(v);
|
||
|
// split into two surrogates:
|
||
|
*m_position++ = static_cast<std::uint16_t>(v >> 10) + detail::high_surrogate_base;
|
||
|
*m_position++ = static_cast<std::uint16_t>(v & detail::ten_bit_mask) + detail::low_surrogate_base;
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
// 16-bit code point:
|
||
|
// value must not be a surrogate:
|
||
|
if(detail::is_surrogate(v))
|
||
|
detail::invalid_utf32_code_point(v);
|
||
|
*m_position++ = static_cast<std::uint16_t>(v);
|
||
|
}
|
||
|
}
|
||
|
mutable BaseIterator m_position;
|
||
|
};
|
||
|
|
||
|
template <class BaseIterator>
|
||
|
class utf8_output_iterator
|
||
|
{
|
||
|
public:
|
||
|
typedef void difference_type;
|
||
|
typedef void value_type;
|
||
|
typedef std::uint32_t* pointer;
|
||
|
typedef std::uint32_t& reference;
|
||
|
typedef std::output_iterator_tag iterator_category;
|
||
|
|
||
|
utf8_output_iterator(const BaseIterator& b)
|
||
|
: m_position(b){}
|
||
|
utf8_output_iterator(const utf8_output_iterator& that)
|
||
|
: m_position(that.m_position){}
|
||
|
utf8_output_iterator& operator=(const utf8_output_iterator& that)
|
||
|
{
|
||
|
m_position = that.m_position;
|
||
|
return *this;
|
||
|
}
|
||
|
const utf8_output_iterator& operator*()const
|
||
|
{
|
||
|
return *this;
|
||
|
}
|
||
|
void operator=(std::uint32_t val)const
|
||
|
{
|
||
|
push(val);
|
||
|
}
|
||
|
utf8_output_iterator& operator++()
|
||
|
{
|
||
|
return *this;
|
||
|
}
|
||
|
utf8_output_iterator& operator++(int)
|
||
|
{
|
||
|
return *this;
|
||
|
}
|
||
|
BaseIterator base()const
|
||
|
{
|
||
|
return m_position;
|
||
|
}
|
||
|
private:
|
||
|
void push(std::uint32_t c)const
|
||
|
{
|
||
|
if(c > 0x10FFFFu)
|
||
|
detail::invalid_utf32_code_point(c);
|
||
|
if(c < 0x80u)
|
||
|
{
|
||
|
*m_position++ = static_cast<unsigned char>(c);
|
||
|
}
|
||
|
else if(c < 0x800u)
|
||
|
{
|
||
|
*m_position++ = static_cast<unsigned char>(0xC0u + (c >> 6));
|
||
|
*m_position++ = static_cast<unsigned char>(0x80u + (c & 0x3Fu));
|
||
|
}
|
||
|
else if(c < 0x10000u)
|
||
|
{
|
||
|
*m_position++ = static_cast<unsigned char>(0xE0u + (c >> 12));
|
||
|
*m_position++ = static_cast<unsigned char>(0x80u + ((c >> 6) & 0x3Fu));
|
||
|
*m_position++ = static_cast<unsigned char>(0x80u + (c & 0x3Fu));
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
*m_position++ = static_cast<unsigned char>(0xF0u + (c >> 18));
|
||
|
*m_position++ = static_cast<unsigned char>(0x80u + ((c >> 12) & 0x3Fu));
|
||
|
*m_position++ = static_cast<unsigned char>(0x80u + ((c >> 6) & 0x3Fu));
|
||
|
*m_position++ = static_cast<unsigned char>(0x80u + (c & 0x3Fu));
|
||
|
}
|
||
|
}
|
||
|
mutable BaseIterator m_position;
|
||
|
};
|
||
|
|
||
|
} // namespace boost
|
||
|
|
||
|
#endif // BOOST_REGEX_UNICODE_ITERATOR_HPP
|
||
|
|