ceph/src/boost/boost/io/ostream_joiner.hpp

   1 /*
   2 Copyright 2019 Glen Joseph Fernandes
   3 (glenjofe@gmail.com)
   4
   5 Distributed under the Boost Software License, Version 1.0.
   6 (http://www.boost.org/LICENSE_1_0.txt)
   7 */
   8 #ifndef BOOST_IO_OSTREAM_JOINER_HPP
   9 #define BOOST_IO_OSTREAM_JOINER_HPP
  10
  11 #include <boost/config.hpp>
  12 #include <ostream>
  13 #include <string>
  14 #if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
  15 #if !defined(BOOST_NO_CXX11_HDR_TYPE_TRAITS)
  16 #include <type_traits>
  17 #endif
  18 #include <utility>
  19 #endif
  20
  21 namespace boost {
  22 namespace io {
  23 namespace detail {
  24
  25 #if !defined(BOOST_NO_CXX11_ADDRESSOF)
  26 template<class T>
  27 inline T*
  28 osj_address(T& o)
  29 {
  30     return std::addressof(o);
  31 }
  32 #else
  33 template<class T>
  34 inline T*
  35 osj_address(T& obj)
  36 {
  37     return &obj;
  38 }
  39 #endif
  40
  41 } /* detail */
  42
  43 template<class Delim, class Char = char,
  44     class Traits = std::char_traits<Char> >
  45 class ostream_joiner {
  46 public:
  47     typedef Char char_type;
  48     typedef Traits traits_type;
  49     typedef std::basic_ostream<Char, Traits> ostream_type;
  50     typedef std::output_iterator_tag iterator_category;
  51     typedef void value_type;
  52     typedef void difference_type;
  53     typedef void pointer;
  54     typedef void reference;
  55
  56     ostream_joiner(ostream_type& output, const Delim& delim)
  57         : output_(detail::osj_address(output))
  58         , delim_(delim)
  59         , first_(true) { }
  60
  61 #if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
  62     ostream_joiner(ostream_type& output, Delim&& delim)
  63         : output_(detail::osj_address(output))
  64         , delim_(std::move(delim))
  65         , first_(true) { }
  66 #endif
  67
  68     template<class T>
  69     ostream_joiner& operator=(const T& value) {
  70         if (!first_) {
  71             *output_ << delim_;
  72         }
  73         first_ = false;
  74         *output_ << value;
  75         return *this;
  76     }
  77
  78     ostream_joiner& operator*() BOOST_NOEXCEPT {
  79         return *this;
  80     }
  81
  82     ostream_joiner& operator++() BOOST_NOEXCEPT {
  83         return *this;
  84     }
  85
  86     ostream_joiner& operator++(int) BOOST_NOEXCEPT {
  87         return *this;
  88     }
  89
  90 private:
  91     ostream_type* output_;
  92     Delim delim_;
  93     bool first_;
  94 };
  95
  96 #if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES) && \
  97     !defined(BOOST_NO_CXX11_HDR_TYPE_TRAITS)
  98 template<class Char, class Traits, class Delim>
  99 inline ostream_joiner<typename std::decay<Delim>::type, Char, Traits>
 100 make_ostream_joiner(std::basic_ostream<Char, Traits>& output, Delim&& delim)
 101 {
 102     return ostream_joiner<typename std::decay<Delim>::type, Char,
 103         Traits>(output, std::forward<Delim>(delim));
 104 }
 105 #else
 106 template<class Char, class Traits, class Delim>
 107 inline ostream_joiner<Delim, Char, Traits>
 108 make_ostream_joiner(std::basic_ostream<Char, Traits>& output,
 109     const Delim& delim)
 110 {
 111     return ostream_joiner<Delim, Char, Traits>(output, delim);
 112 }
 113 #endif
 114
 115 } /* io */
 116 } /* boost */
 117
 118 #endif