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*
osj_address(T & o)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
ostream_joiner(ostream_type & output,const Delim & delim)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)
ostream_joiner(ostream_type & output,Delim && delim)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>
operator =(const T & value)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
operator *()78 ostream_joiner& operator*() BOOST_NOEXCEPT {
79 return *this;
80 }
81
operator ++()82 ostream_joiner& operator++() BOOST_NOEXCEPT {
83 return *this;
84 }
85
operator ++(int)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>
make_ostream_joiner(std::basic_ostream<Char,Traits> & output,Delim && delim)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>
make_ostream_joiner(std::basic_ostream<Char,Traits> & output,const Delim & delim)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
119