1/* iostream specialisations for result and outcome
2(C) 2017-2024 Niall Douglas <http://www.nedproductions.biz/> (21 commits)
3File Created: July 2017
4
5
6Boost Software License - Version 1.0 - August 17th, 2003
7
8Permission is hereby granted, free of charge, to any person or organization
9obtaining a copy of the software and accompanying documentation covered by
10this license (the "Software") to use, reproduce, display, distribute,
11execute, and transmit the Software, and to prepare derivative works of the
12Software, and to permit third-parties to whom the Software is furnished to
13do so, all subject to the following:
14
15The copyright notices in the Software and this entire statement, including
16the above license grant, this restriction and the following disclaimer,
17must be included in all copies of the Software, in whole or in part, and
18all derivative works of the Software, unless such copies or derivative
19works are solely in the form of machine-executable object code generated by
20a source language processor.
21
22THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
23IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
24FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
25SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
26FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
27ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
28DEALINGS IN THE SOFTWARE.
29*/
30
31#ifndef BOOST_OUTCOME_IOSTREAM_SUPPORT_HPP
32#define BOOST_OUTCOME_IOSTREAM_SUPPORT_HPP
33
34#include "outcome.hpp"
35
36#include <iostream>
37#include <sstream>
38
39BOOST_OUTCOME_V2_NAMESPACE_BEGIN
40
41namespace detail
42{
43 template <class T> typename std::add_lvalue_reference<T>::type lvalueref() noexcept;
44
45 template <template <class, class> class ValueStorage, class T, class E> inline std::ostream &value_storage_out(std::ostream &s, const ValueStorage<T, E> &v)
46 {
47 s << static_cast<uint16_t>(v._status.status_value) << " " << v._status.spare_storage_value << " ";
48 if(v._status.have_value())
49 {
50 s << v._value; // NOLINT
51 }
52 if(v._status.have_error())
53 {
54 s << v._error; // NOLINT
55 }
56 return s;
57 }
58 template <template <class, class> class ValueStorage, class E> inline std::ostream &value_storage_out(std::ostream &s, const ValueStorage<void, E> &v)
59 {
60 s << static_cast<uint16_t>(v._status.status_value) << " " << v._status.spare_storage_value << " ";
61 if(v._status.have_error())
62 {
63 s << v._error; // NOLINT
64 }
65 return s;
66 }
67 template <template <class, class> class ValueStorage, class T> inline std::ostream &value_storage_out(std::ostream &s, const ValueStorage<T, void> &v)
68 {
69 s << static_cast<uint16_t>(v._status.status_value) << " " << v._status.spare_storage_value << " ";
70 if(v._status.have_value())
71 {
72 s << v._value; // NOLINT
73 }
74 return s;
75 }
76
77 template <class T, class E> inline std::ostream &operator<<(std::ostream &s, const value_storage_trivial<T, E> &v) { return value_storage_out(s, v); }
78 template <class T, class E> inline std::ostream &operator<<(std::ostream &s, const value_storage_nontrivial<T, E> &v) { return value_storage_out(s, v); }
79
80 template <template <class, class> class ValueStorage, class T, class E> inline std::istream &value_storage_in(std::istream &s, ValueStorage<T, E> &v)
81 {
82 using type = ValueStorage<T, E>;
83 v.~type();
84 new(&v) type;
85 uint16_t x, y;
86 s >> x >> y;
87 v._status.status_value = static_cast<detail::status>(x);
88 v._status.spare_storage_value = y;
89 if(v._status.have_value())
90 {
91 new(BOOST_OUTCOME_ADDRESS_OF(v._value)) decltype(v._value)(); // NOLINT
92 s >> v._value; // NOLINT
93 }
94 if(v._status.have_error())
95 {
96 new(BOOST_OUTCOME_ADDRESS_OF(v._error)) decltype(v._error)(); // NOLINT
97 s >> v._error; // NOLINT
98 }
99 return s;
100 }
101 template <template <class, class> class ValueStorage, class E> inline std::istream &value_storage_in(std::istream &s, ValueStorage<void, E> &v)
102 {
103 using type = ValueStorage<void, E>;
104 v.~type();
105 new(&v) type;
106 uint16_t x, y;
107 s >> x >> y;
108 v._status.status_value = static_cast<detail::status>(x);
109 v._status.spare_storage_value = y;
110 if(v._status.have_error())
111 {
112 new(BOOST_OUTCOME_ADDRESS_OF(v._error)) decltype(v._error)(); // NOLINT
113 s >> v._error; // NOLINT
114 }
115 return s;
116 }
117 template <template <class, class> class ValueStorage, class T> inline std::istream &value_storage_in(std::istream &s, ValueStorage<T, void> &v)
118 {
119 using type = ValueStorage<T, void>;
120 v.~type();
121 new(&v) type;
122 uint16_t x, y;
123 s >> x >> y;
124 v._status.status_value = static_cast<detail::status>(x);
125 v._status.spare_storage_value = y;
126 if(v._status.have_value())
127 {
128 new(BOOST_OUTCOME_ADDRESS_OF(v._value)) decltype(v._value)(); // NOLINT
129 s >> v._value; // NOLINT
130 }
131 return s;
132 }
133 template <class T, class E> inline std::istream &operator>>(std::istream &s, value_storage_trivial<T, E> &v) { return value_storage_in(s, v); }
134 template <class T, class E> inline std::istream &operator>>(std::istream &s, value_storage_nontrivial<T, E> &v) { return value_storage_in(s, v); }
135 BOOST_OUTCOME_TEMPLATE(class T)
136 BOOST_OUTCOME_TREQUIRES(BOOST_OUTCOME_TPRED(!std::is_constructible<std::error_code, T>::value))
137 inline std::string safe_message(T && /*unused*/) { return {}; }
138 inline std::string safe_message(const std::error_code &ec) { return " (" + ec.message() + ")"; }
139} // namespace detail
140
141/*! AWAITING HUGO JSON CONVERSION TOOL
142SIGNATURE NOT RECOGNISED
143*/
144BOOST_OUTCOME_TEMPLATE(class R, class S, class P)
145BOOST_OUTCOME_TREQUIRES(BOOST_OUTCOME_TEXPR(detail::lvalueref<std::istream>() >> detail::lvalueref<R>()), BOOST_OUTCOME_TEXPR(detail::lvalueref<std::istream>() >> detail::lvalueref<S>()))
146inline std::istream &operator>>(std::istream &s, basic_result<R, S, P> &v)
147{
148 s >> v._iostreams_state();
149 if(v.has_error())
150 {
151 s >> v.assume_error();
152 }
153 return s;
154}
155/*! AWAITING HUGO JSON CONVERSION TOOL
156SIGNATURE NOT RECOGNISED
157*/
158BOOST_OUTCOME_TEMPLATE(class R, class S, class P)
159BOOST_OUTCOME_TREQUIRES(BOOST_OUTCOME_TEXPR(detail::lvalueref<std::ostream>() << detail::lvalueref<R>()), BOOST_OUTCOME_TEXPR(detail::lvalueref<std::ostream>() << detail::lvalueref<S>()))
160inline std::ostream &operator<<(std::ostream &s, const basic_result<R, S, P> &v)
161{
162 s << v._iostreams_state();
163 if(v.has_error())
164 {
165 s << v.assume_error();
166 }
167 return s;
168}
169/*! AWAITING HUGO JSON CONVERSION TOOL
170SIGNATURE NOT RECOGNISED
171*/
172template <class R, class S, class P> inline std::string print(const basic_result<R, S, P> &v)
173{
174 std::stringstream s;
175 if(v.has_value())
176 {
177 s << v.value();
178 }
179 if(v.has_error())
180 {
181 s << v.error() << detail::safe_message(v.error());
182 }
183 return s.str();
184}
185/*! AWAITING HUGO JSON CONVERSION TOOL
186SIGNATURE NOT RECOGNISED
187*/
188template <class S, class P> inline std::string print(const basic_result<void, S, P> &v)
189{
190 std::stringstream s;
191 if(v.has_value())
192 {
193 s << "(+void)";
194 }
195 if(v.has_error())
196 {
197 s << v.error() << detail::safe_message(v.error());
198 }
199 return s.str();
200}
201/*! AWAITING HUGO JSON CONVERSION TOOL
202SIGNATURE NOT RECOGNISED
203*/
204template <class R, class P> inline std::string print(const basic_result<R, void, P> &v)
205{
206 std::stringstream s;
207 if(v.has_value())
208 {
209 s << v.value();
210 }
211 if(v.has_error())
212 {
213 s << "(-void)";
214 }
215 return s.str();
216}
217/*! AWAITING HUGO JSON CONVERSION TOOL
218SIGNATURE NOT RECOGNISED
219*/
220template <class P> inline std::string print(const basic_result<void, void, P> &v)
221{
222 std::stringstream s;
223 if(v.has_value())
224 {
225 s << "(+void)";
226 }
227 if(v.has_error())
228 {
229 s << "(-void)";
230 }
231 return s.str();
232}
233
234/*! AWAITING HUGO JSON CONVERSION TOOL
235SIGNATURE NOT RECOGNISED
236*/
237BOOST_OUTCOME_TEMPLATE(class R, class S, class P, class N)
238BOOST_OUTCOME_TREQUIRES(BOOST_OUTCOME_TEXPR(detail::lvalueref<std::istream>() >> detail::lvalueref<R>()), BOOST_OUTCOME_TEXPR(detail::lvalueref<std::istream>() >> detail::lvalueref<S>()), BOOST_OUTCOME_TEXPR(detail::lvalueref<std::istream>() >> detail::lvalueref<P>()))
239inline std::istream &operator>>(std::istream &s, outcome<R, S, P, N> &v)
240{
241 s >> v._iostreams_state();
242 if(v.has_error())
243 {
244 s >> v.assume_error();
245 }
246 if(v.has_exception())
247 {
248 s >> v.assume_exception();
249 }
250 return s;
251}
252/*! AWAITING HUGO JSON CONVERSION TOOL
253SIGNATURE NOT RECOGNISED
254*/
255BOOST_OUTCOME_TEMPLATE(class R, class S, class P, class N)
256BOOST_OUTCOME_TREQUIRES(BOOST_OUTCOME_TEXPR(detail::lvalueref<std::ostream>() << detail::lvalueref<R>()), BOOST_OUTCOME_TEXPR(detail::lvalueref<std::ostream>() << detail::lvalueref<S>()), BOOST_OUTCOME_TEXPR(detail::lvalueref<std::ostream>() << detail::lvalueref<P>()))
257inline std::ostream &operator<<(std::ostream &s, const outcome<R, S, P, N> &v)
258{
259 s << v._iostreams_state();
260 if(v.has_error())
261 {
262 s << v.assume_error();
263 }
264 if(v.has_exception())
265 {
266 s << v.assume_exception();
267 }
268 return s;
269}
270/*! AWAITING HUGO JSON CONVERSION TOOL
271SIGNATURE NOT RECOGNISED
272*/
273template <class R, class S, class P, class N> inline std::string print(const outcome<R, S, P, N> &v)
274{
275 std::stringstream s;
276 int total = static_cast<int>(v.has_value()) + static_cast<int>(v.has_error()) + static_cast<int>(v.has_exception());
277 if(total > 1)
278 {
279 s << "{ ";
280 }
281 s << print(static_cast<const basic_result<R, S, N> &>(static_cast<const detail::basic_result_final<R, S, N> &>(v))); // NOLINT
282 if(total > 1)
283 {
284 s << ", ";
285 }
286 if(v.has_exception())
287 {
288#ifndef BOOST_NO_EXCEPTIONS
289 try
290 {
291 rethrow_exception(v.exception());
292 }
293 catch(const std::system_error &e)
294 {
295 s << "std::system_error code " << e.code() << ": " << e.what();
296 }
297 catch(const std::exception &e)
298 {
299 s << "std::exception: " << e.what();
300 }
301 catch(...)
302#endif
303 {
304 s << "unknown exception";
305 }
306 }
307 if(total > 1)
308 {
309 s << " }";
310 }
311 return s.str();
312}
313BOOST_OUTCOME_V2_NAMESPACE_END
314
315#endif
316

source code of boost/libs/outcome/include/boost/outcome/iostream_support.hpp