add boost on mac

macx64/include/boost/outcome/experimental/status-code/error.hpp

@@ -0,0 +1,65 @@
+/* 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_ERROR_HPP
+#define BOOST_OUTCOME_SYSTEM_ERROR2_ERROR_HPP
+
+#include "errored_status_code.hpp"
+#include "system_code.hpp"
+
+BOOST_OUTCOME_SYSTEM_ERROR2_NAMESPACE_BEGIN
+
+/*! An erased `system_code` which is always a failure. The closest equivalent to
+`std::error_code`, except it cannot be null and cannot be modified.
+
+This refines `system_code` into an `error` object meeting the requirements of
+[P0709 Zero-overhead deterministic exceptions](https://wg21.link/P0709).
+
+Differences from `system_code`:
+
+- Always a failure (this is checked at construction, and if not the case,
+the program is terminated as this is a logic error)
+- No default construction.
+- No empty state possible.
+- Is immutable.
+
+As with `system_code`, it remains guaranteed to be two CPU registers in size,
+and move relocating.
+*/
+using error = errored_status_code<erased<system_code::value_type>>;
+
+#ifndef NDEBUG
+static_assert(sizeof(error) == 2 * sizeof(void *), "error is not exactly two pointers in size!");
+static_assert(traits::is_move_relocating<error>::value, "error is not move relocating!");
+#endif
+
+BOOST_OUTCOME_SYSTEM_ERROR2_NAMESPACE_END
+
+#endif