src/plugins/litehtml_viewer/litehtml/tstring_view.h

   1 // Copyright (C) 2020-2021 Primate Labs Inc.
   2 // All rights reserved.
   3 //
   4 // Redistribution and use in source and binary forms, with or without
   5 // modification, are permitted provided that the following conditions are
   6 // met:
   7 //
   8 //    * Redistributions of source code must retain the above copyright
   9 // notice, this list of conditions and the following disclaimer.
  10 //    * Redistributions in binary form must reproduce the above
  11 // copyright notice, this list of conditions and the following disclaimer
  12 // in the documentation and/or other materials provided with the
  13 // distribution.
  14 //    * Neither the names of the copyright holders nor the names of their
  15 // contributors may be used to endorse or promote products derived from
  16 // this software without specific prior written permission.
  17 //
  18 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  19 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  20 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  21 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  22 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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  24 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  25 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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  28 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29
  30 #ifndef LITEHTML_TSTRING_VIEW_H__
  31 #define LITEHTML_TSTRING_VIEW_H__
  32
  33 #include <cstddef>
  34 #include <ostream>
  35
  36 #include "os_types.h"
  37
  38 namespace litehtml {
  39
  40 // tstring_view is a string reference type that provides a view into a string
  41 // that is owned elsewhere (e.g., by a std::string object).
  42
  43 // tstring_view implements the same interface as std::base_string_view in the
  44 // standard library.  When litehtml moves to C++17 consider replacing the
  45 // tstring_view implementation with the standard library implementations
  46 // (e.g., via a using statement).
  47
  48 class tstring_view {
  49 public:
  50     using value_type = char;
  51
  52     using pointer = char*;
  53
  54     using const_pointer = const char*;
  55
  56     using reference = char&;
  57
  58     using const_reference = const char&;
  59
  60     using iterator = const_pointer;
  61
  62     using const_iterator = const_pointer;
  63
  64     using size_type = size_t;
  65
  66     using difference_type = std::ptrdiff_t;
  67
  68 public:
  69     tstring_view() = default;
  70
  71     tstring_view(const tstring_view& other) = default;
  72
  73     tstring_view(const_pointer s, size_type size)
  74     : data_(s)
  75     , size_(size)
  76     {
  77     }
  78
  79     constexpr const_iterator begin() const
  80     {
  81         return data_;
  82     }
  83
  84     constexpr const_iterator cbegin() const
  85     {
  86         return data_;
  87     }
  88
  89     constexpr const_iterator end() const
  90     {
  91         return data_ + size_;
  92     }
  93
  94     constexpr const_iterator cend() const
  95     {
  96         return data_ + size_;
  97     }
  98
  99     constexpr const_reference operator[](size_type offset) const
 100     {
 101         return *(data_ + offset);
 102     }
 103
 104     constexpr const_pointer data() const
 105     {
 106         return data_;
 107     }
 108
 109     size_type size() const
 110     {
 111         return size_;
 112     }
 113
 114     size_type length() const
 115     {
 116         return size_;
 117     }
 118
 119     bool empty() const
 120     {
 121         return (size_ == 0);
 122     }
 123
 124 private:
 125     const_pointer data_ = nullptr;
 126
 127     size_type size_ = 0;
 128 };
 129
 130 std::basic_ostream<tstring_view::value_type>& operator<<(
 131     std::basic_ostream<tstring_view::value_type>&,
 132     tstring_view str);
 133
 134 } // namespace litehtml
 135
 136 #endif // LITEHTML_TSTRING_VIEW_H__