outcome/detail/try.h

0001 /* Try operation macros
0002 (C) 2017-2024 Niall Douglas <http://www.nedproductions.biz/> (20 commits)
0003 File Created: July 2017
0004
0005
0006 Boost Software License - Version 1.0 - August 17th, 2003
0007
0008 Permission is hereby granted, free of charge, to any person or organization
0009 obtaining a copy of the software and accompanying documentation covered by
0010 this license (the "Software") to use, reproduce, display, distribute,
0011 execute, and transmit the Software, and to prepare derivative works of the
0012 Software, and to permit third-parties to whom the Software is furnished to
0013 do so, all subject to the following:
0014
0015 The copyright notices in the Software and this entire statement, including
0016 the above license grant, this restriction and the following disclaimer,
0017 must be included in all copies of the Software, in whole or in part, and
0018 all derivative works of the Software, unless such copies or derivative
0019 works are solely in the form of machine-executable object code generated by
0020 a source language processor.
0021
0022 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
0023 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
0024 FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
0025 SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
0026 FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
0027 ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
0028 DEALINGS IN THE SOFTWARE.
0029 */
0030
0031 #ifndef BOOST_OUTCOME_TRY_H
0032 #define BOOST_OUTCOME_TRY_H
0033
0034 #if !defined(__clang__) && defined(__GNUC__) && __GNUC__ >= 8
0035 #pragma GCC diagnostic push
0036 #pragma GCC diagnostic ignored "-Wparentheses"
0037 #endif
0038
0039 #define BOOST_OUTCOME_TRY_GLUE2(x, y) x##y
0040 #define BOOST_OUTCOME_TRY_GLUE(x, y) BOOST_OUTCOME_TRY_GLUE2(x, y)
0041 #define BOOST_OUTCOME_TRY_UNIQUE_NAME BOOST_OUTCOME_TRY_GLUE(_outcome_try_unique_name_temporary, __COUNTER__)
0042
0043 #define BOOST_OUTCOME_TRY_RETURN_ARG_COUNT(_1_, _2_, _3_, _4_, _5_, _6_, _7_, _8_, count, ...) count
0044 #define BOOST_OUTCOME_TRY_EXPAND_ARGS(args) BOOST_OUTCOME_TRY_RETURN_ARG_COUNT args
0045 #define BOOST_OUTCOME_TRY_COUNT_ARGS_MAX8(...) BOOST_OUTCOME_TRY_EXPAND_ARGS((__VA_ARGS__, 8, 7, 6, 5, 4, 3, 2, 1, 0))
0046 #define BOOST_OUTCOME_TRY_OVERLOAD_MACRO2(name, count) name##count
0047 #define BOOST_OUTCOME_TRY_OVERLOAD_MACRO1(name, count) BOOST_OUTCOME_TRY_OVERLOAD_MACRO2(name, count)
0048 #define BOOST_OUTCOME_TRY_OVERLOAD_MACRO(name, count) BOOST_OUTCOME_TRY_OVERLOAD_MACRO1(name, count)
0049 #define BOOST_OUTCOME_TRY_OVERLOAD_GLUE(x, y) x y
0050 #define BOOST_OUTCOME_TRY_CALL_OVERLOAD(name, ...)                                                                                                                   \
0051   BOOST_OUTCOME_TRY_OVERLOAD_GLUE(BOOST_OUTCOME_TRY_OVERLOAD_MACRO(name, BOOST_OUTCOME_TRY_COUNT_ARGS_MAX8(__VA_ARGS__)), (__VA_ARGS__))
0052
0053 #define _OUTCOME_TRY_RETURN_ARG_COUNT(_1_, _2_, _3_, _4_, _5_, _6_, _7_, _8_, count, ...) count
0054 #define _OUTCOME_TRY_EXPAND_ARGS(args) _OUTCOME_TRY_RETURN_ARG_COUNT args
0055 #define _OUTCOME_TRY_COUNT_ARGS_MAX8(...) _OUTCOME_TRY_EXPAND_ARGS((__VA_ARGS__, 8, 7, 6, 5, 4, 3, 2, 1, 0))
0056 #define _OUTCOME_TRY_OVERLOAD_MACRO2(name, count) name##count
0057 #define _OUTCOME_TRY_OVERLOAD_MACRO1(name, count) _OUTCOME_TRY_OVERLOAD_MACRO2(name, count)
0058 #define _OUTCOME_TRY_OVERLOAD_MACRO(name, count) _OUTCOME_TRY_OVERLOAD_MACRO1(name, count)
0059 #define _OUTCOME_TRY_OVERLOAD_GLUE(x, y) x y
0060 #define _OUTCOME_TRY_CALL_OVERLOAD(name, ...)                                                                                                                  \
0061   _OUTCOME_TRY_OVERLOAD_GLUE(_OUTCOME_TRY_OVERLOAD_MACRO(name, _OUTCOME_TRY_COUNT_ARGS_MAX8(__VA_ARGS__)), (__VA_ARGS__))
0062
0063 #if !defined(BOOST_OUTCOME_TRY_LIKELY_IF) && defined(__has_cpp_attribute)
0064 #if __has_cpp_attribute(likely)
0065 #define BOOST_OUTCOME_TRY_LIKELY_IF(...) if(__VA_ARGS__) [[likely]]
0066 #endif
0067 #endif
0068 #ifndef BOOST_OUTCOME_TRY_LIKELY_IF
0069 #if defined(__clang__) || defined(__GNUC__)
0070 #define BOOST_OUTCOME_TRY_LIKELY_IF(...) if(__builtin_expect(!!(__VA_ARGS__), 1))
0071 #else
0072 #define BOOST_OUTCOME_TRY_LIKELY_IF(...) if(__VA_ARGS__)
0073 #endif
0074 #endif
0075
0076 #ifdef __cplusplus
0077 #define BOOST_OUTCOME_TRYV2_UNIQUE_STORAGE_AUTO(...) auto
0078 #else
0079 #define BOOST_OUTCOME_TRYV2_UNIQUE_STORAGE_AUTO(...) __typeof__(__VA_ARGS__)
0080 #endif
0081
0082 #define BOOST_OUTCOME_TRYV2_UNIQUE_STORAGE_UNPACK(...) __VA_ARGS__
0083 #define BOOST_OUTCOME_TRYV2_UNIQUE_STORAGE_DEDUCE3(unique, ...) BOOST_OUTCOME_TRYV2_UNIQUE_STORAGE_AUTO(__VA_ARGS__) unique = (__VA_ARGS__)
0084 #define BOOST_OUTCOME_TRYV2_UNIQUE_STORAGE_DEDUCE2(x) x
0085 #define BOOST_OUTCOME_TRYV2_UNIQUE_STORAGE_DEDUCE(unique, x, ...) BOOST_OUTCOME_TRYV2_UNIQUE_STORAGE_DEDUCE2(BOOST_OUTCOME_TRYV2_UNIQUE_STORAGE_DEDUCE3(unique, __VA_ARGS__))
0086 #define BOOST_OUTCOME_TRYV2_UNIQUE_STORAGE_SPECIFIED3(unique, x, y, ...) x unique = (__VA_ARGS__)
0087 #define BOOST_OUTCOME_TRYV2_UNIQUE_STORAGE_SPECIFIED2(x) x
0088 #define BOOST_OUTCOME_TRYV2_UNIQUE_STORAGE_SPECIFIED(unique, ...)                                                                                                    \
0089   BOOST_OUTCOME_TRYV2_UNIQUE_STORAGE_SPECIFIED2(BOOST_OUTCOME_TRYV2_UNIQUE_STORAGE_SPECIFIED3(unique, __VA_ARGS__))
0090 #define BOOST_OUTCOME_TRYV2_UNIQUE_STORAGE1(...) BOOST_OUTCOME_TRYV2_UNIQUE_STORAGE_DEDUCE
0091 #define BOOST_OUTCOME_TRYV2_UNIQUE_STORAGE2(...) BOOST_OUTCOME_TRYV2_UNIQUE_STORAGE_SPECIFIED
0092 #define BOOST_OUTCOME_TRYV2_UNIQUE_STORAGE(unique, spec, ...)                                                                                                        \
0093   _OUTCOME_TRY_CALL_OVERLOAD(BOOST_OUTCOME_TRYV2_UNIQUE_STORAGE, BOOST_OUTCOME_TRYV2_UNIQUE_STORAGE_UNPACK spec)                                                           \
0094   (unique, BOOST_OUTCOME_TRYV2_UNIQUE_STORAGE_UNPACK spec, __VA_ARGS__)
0095
0096 #define BOOST_OUTCOME_TRY2_VAR_SECOND2(x, var) var
0097 #define BOOST_OUTCOME_TRY2_VAR_SECOND3(x, y, ...) x y
0098 #define BOOST_OUTCOME_TRY2_VAR(spec) _OUTCOME_TRY_CALL_OVERLOAD(BOOST_OUTCOME_TRY2_VAR_SECOND, BOOST_OUTCOME_TRYV2_UNIQUE_STORAGE_UNPACK spec, spec)
0099
0100 #if !defined(__clang__) && defined(__GNUC__) && __GNUC__ >= 8
0101 #pragma GCC diagnostic pop
0102 #endif
0103
0104 #endif