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Diffstat (limited to 'boost/outcome/experimental/status-code/posix_code.hpp')
-rw-r--r-- | boost/outcome/experimental/status-code/posix_code.hpp | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/boost/outcome/experimental/status-code/posix_code.hpp b/boost/outcome/experimental/status-code/posix_code.hpp new file mode 100644 index 0000000000..f796a1ea65 --- /dev/null +++ b/boost/outcome/experimental/status-code/posix_code.hpp @@ -0,0 +1,151 @@ +/* Proposed SG14 status_code +(C) 2018-2019 Niall Douglas <http://www.nedproductions.biz/> (5 commits) +File Created: Feb 2018 + + +Boost Software License - Version 1.0 - August 17th, 2003 + +Permission is hereby granted, free of charge, to any person or organization +obtaining a copy of the software and accompanying documentation covered by +this license (the "Software") to use, reproduce, display, distribute, +execute, and transmit the Software, and to prepare derivative works of the +Software, and to permit third-parties to whom the Software is furnished to +do so, all subject to the following: + +The copyright notices in the Software and this entire statement, including +the above license grant, this restriction and the following disclaimer, +must be included in all copies of the Software, in whole or in part, and +all derivative works of the Software, unless such copies or derivative +works are solely in the form of machine-executable object code generated by +a source language processor. + +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT +SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE +FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE, +ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER +DEALINGS IN THE SOFTWARE. +*/ + +#ifndef BOOST_OUTCOME_SYSTEM_ERROR2_POSIX_CODE_HPP +#define BOOST_OUTCOME_SYSTEM_ERROR2_POSIX_CODE_HPP + +#include "generic_code.hpp" + +#include <cstring> // for strchr and strerror_r + +BOOST_OUTCOME_SYSTEM_ERROR2_NAMESPACE_BEGIN + +class _posix_code_domain; +//! A POSIX error code, those returned by `errno`. +using posix_code = status_code<_posix_code_domain>; +//! A specialisation of `status_error` for the POSIX error code domain. +using posix_error = status_error<_posix_code_domain>; + +/*! The implementation of the domain for POSIX error codes, those returned by `errno`. +*/ +class _posix_code_domain : public status_code_domain +{ + template <class DomainType> friend class status_code; + template <class StatusCode> friend class detail::indirecting_domain; + using _base = status_code_domain; + + static _base::string_ref _make_string_ref(int c) noexcept + { + char buffer[1024] = ""; +#ifdef _WIN32 + strerror_s(buffer, sizeof(buffer), c); +#elif defined(__linux__) + char *s = strerror_r(c, buffer, sizeof(buffer)); // NOLINT + if(s != nullptr) + { + strncpy(buffer, s, sizeof(buffer)); // NOLINT + buffer[1023] = 0; + } +#else + strerror_r(c, buffer, sizeof(buffer)); +#endif + size_t length = strlen(buffer); // NOLINT + auto *p = static_cast<char *>(malloc(length + 1)); // NOLINT + if(p == nullptr) + { + return _base::string_ref("failed to get message from system"); + } + memcpy(p, buffer, length + 1); // NOLINT + return _base::atomic_refcounted_string_ref(p, length); + } + +public: + //! The value type of the POSIX code, which is an `int` + using value_type = int; + using _base::string_ref; + + //! Default constructor + constexpr explicit _posix_code_domain(typename _base::unique_id_type id = 0xa59a56fe5f310933) noexcept : _base(id) {} + _posix_code_domain(const _posix_code_domain &) = default; + _posix_code_domain(_posix_code_domain &&) = default; + _posix_code_domain &operator=(const _posix_code_domain &) = default; + _posix_code_domain &operator=(_posix_code_domain &&) = default; + ~_posix_code_domain() = default; + + //! Constexpr singleton getter. Returns constexpr posix_code_domain variable. + static inline constexpr const _posix_code_domain &get(); + + virtual string_ref name() const noexcept override { return string_ref("posix domain"); } // NOLINT +protected: + virtual bool _do_failure(const status_code<void> &code) const noexcept override // NOLINT + { + assert(code.domain() == *this); // NOLINT + return static_cast<const posix_code &>(code).value() != 0; // NOLINT + } + virtual bool _do_equivalent(const status_code<void> &code1, const status_code<void> &code2) const noexcept override // NOLINT + { + assert(code1.domain() == *this); // NOLINT + const auto &c1 = static_cast<const posix_code &>(code1); // NOLINT + if(code2.domain() == *this) + { + const auto &c2 = static_cast<const posix_code &>(code2); // NOLINT + return c1.value() == c2.value(); + } + if(code2.domain() == generic_code_domain) + { + const auto &c2 = static_cast<const generic_code &>(code2); // NOLINT + if(static_cast<int>(c2.value()) == c1.value()) + { + return true; + } + } + return false; + } + virtual generic_code _generic_code(const status_code<void> &code) const noexcept override // NOLINT + { + assert(code.domain() == *this); // NOLINT + const auto &c = static_cast<const posix_code &>(code); // NOLINT + return generic_code(static_cast<errc>(c.value())); + } + virtual string_ref _do_message(const status_code<void> &code) const noexcept override // NOLINT + { + assert(code.domain() == *this); // NOLINT + const auto &c = static_cast<const posix_code &>(code); // NOLINT + return _make_string_ref(c.value()); + } +#if defined(_CPPUNWIND) || defined(__EXCEPTIONS) || defined(BOOST_OUTCOME_STANDARDESE_IS_IN_THE_HOUSE) + BOOST_OUTCOME_SYSTEM_ERROR2_NORETURN virtual void _do_throw_exception(const status_code<void> &code) const override // NOLINT + { + assert(code.domain() == *this); // NOLINT + const auto &c = static_cast<const posix_code &>(code); // NOLINT + throw status_error<_posix_code_domain>(c); + } +#endif +}; +//! A constexpr source variable for the POSIX code domain, which is that of `errno`. Returned by `_posix_code_domain::get()`. +constexpr _posix_code_domain posix_code_domain; +inline constexpr const _posix_code_domain &_posix_code_domain::get() +{ + return posix_code_domain; +} + +BOOST_OUTCOME_SYSTEM_ERROR2_NAMESPACE_END + +#endif |