add boost on mac

macx64/include/boost/outcome/detail/basic_outcome_failure_observers.hpp

@@ -0,0 +1,100 @@
+/* Failure observers for outcome type
+(C) 2017-2019 Niall Douglas <http://www.nedproductions.biz/> (59 commits)
+File Created: Oct 2017
+
+
+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_BASIC_OUTCOME_FAILURE_OBSERVERS_HPP
+#define BOOST_OUTCOME_BASIC_OUTCOME_FAILURE_OBSERVERS_HPP
+
+#include "basic_result_storage.hpp"
+
+BOOST_OUTCOME_V2_NAMESPACE_EXPORT_BEGIN
+
+namespace detail
+{
+  namespace adl
+  {
+    struct search_detail_adl
+    {
+    };
+    BOOST_OUTCOME_TEMPLATE(class S)                                                                        //
+    BOOST_OUTCOME_TREQUIRES(BOOST_OUTCOME_TEXPR(basic_outcome_failure_exception_from_error(std::declval<S>())))  //
+    inline auto _delayed_lookup_basic_outcome_failure_exception_from_error(const S &ec, search_detail_adl /*unused*/)
+    {
+      // ADL discovered
+      return basic_outcome_failure_exception_from_error(ec);
+    }
+  }                                        // namespace adl
+#if defined(_MSC_VER) && _MSC_VER <= 1920  // VS2019
+  // VS2017 and VS2019 with /permissive- chokes on the correct form due to over eager early instantiation.
+  template <class S, class P> inline void _delayed_lookup_basic_outcome_failure_exception_from_error(...) { static_assert(sizeof(S) == 0, "No specialisation for these error and exception types available!"); }
+#else
+  template <class S, class P> inline void _delayed_lookup_basic_outcome_failure_exception_from_error(...) = delete;  // NOLINT No specialisation for these error and exception types available!
+#endif
+
+  template <class exception_type> inline exception_type current_exception_or_fatal(std::exception_ptr e) { std::rethrow_exception(e); }
+  template <> inline std::exception_ptr current_exception_or_fatal<std::exception_ptr>(std::exception_ptr e) { return e; }
+
+  template <class Base, class R, class S, class P, class NoValuePolicy> class basic_outcome_failure_observers : public Base
+  {
+  public:
+    using exception_type = P;
+    using Base::Base;
+
+    exception_type failure() const noexcept
+    {
+#ifndef BOOST_NO_EXCEPTIONS
+      try
+#endif
+      {
+        if((this->_state._status & detail::status_have_exception) != 0)
+        {
+          return this->assume_exception();
+        }
+        if((this->_state._status & detail::status_have_error) != 0)
+        {
+          return _delayed_lookup_basic_outcome_failure_exception_from_error(this->assume_error(), adl::search_detail_adl());
+        }
+        return exception_type();
+      }
+#ifndef BOOST_NO_EXCEPTIONS
+      catch(...)
+      {
+        // Return the failure if exception_type is std::exception_ptr,
+        // otherwise terminate same as throwing an exception inside noexcept
+        return current_exception_or_fatal<exception_type>(std::current_exception());
+      }
+#endif
+    }
+  };
+
+}  // namespace detail
+
+BOOST_OUTCOME_V2_NAMESPACE_END
+
+#endif