Add Optional class

LibCarla/source/carla/Optional.h

@@ -0,0 +1,36 @@
+// Copyright (c) 2017 Computer Vision Center (CVC) at the Universitat Autonoma
+// de Barcelona (UAB).
+//
+// This work is licensed under the terms of the MIT license.
+// For a copy, see <https://opensource.org/licenses/MIT>.
+
+#pragma once
+
+#include <boost/optional.hpp>
+
+namespace carla {
+
+  template <typename T>
+  class Optional : private boost::optional<T> {
+    using parent_type = boost::optional<T>;
+  public:
+
+    template <typename... Args>
+    explicit Optional(Args &&... args)
+      : parent_type(std::forward<Args>(args)...) {}
+
+    using parent_type::operator*;
+    using parent_type::operator->;
+    using parent_type::operator=;
+    using parent_type::emplace;
+    using parent_type::reset;
+    using parent_type::swap;
+    // using parent_type::value; disabled to avoid exceptions.
+    using parent_type::value_or;
+
+    bool has_value() const {
+      return parent_type::is_initialized();
+    }
+  };
+
+} // namespace carla

LibCarla/source/compiler/disable-ue4-macros.h

@@ -20,6 +20,9 @@
 #  ifndef __cpp_coroutines
 #    define __cpp_coroutines 0
 #  endif // __cpp_coroutines
+#  ifndef __cpp_noexcept_function_type
+#    define __cpp_noexcept_function_type 0
+#  endif // __cpp_noexcept_function_type
 #endif // defined(__clang__)
 
 // NOTE(Andrei): disable warning generated by undefined macros