replace boost optional with mapbox optional

include/mbgl/text/types.hpp

@@ -3,11 +3,10 @@
 
 #include <mbgl/util/vec.hpp>
 #include <mbgl/util/rect.hpp>
+#include <mbgl/util/optional.hpp>
 #include <array>
 #include <vector>
 
-#include <boost/optional.hpp>
-
 namespace mbgl {
 
 typedef vec2<float> CollisionPoint;
@@ -53,7 +52,7 @@ struct GlyphBox {
     float minScale = 0.0f;
     float maxScale = std::numeric_limits<float>::infinity();
     float padding = 0.0f;
-    boost::optional<CollisionRect> hBox;
+    mapbox::util::optional<CollisionRect> hBox;
 };
 
 typedef std::vector<GlyphBox> GlyphBoxes;
@@ -88,7 +87,7 @@ typedef std::vector<PlacedGlyph> PlacedGlyphs;
 struct PlacementBox {
     CollisionAnchor anchor;
     CollisionRect box;
-    boost::optional<CollisionRect> hBox;
+    mapbox::util::optional<CollisionRect> hBox;
     PlacementRange placementRange = {{0.0f, 0.0f}};
     float placementScale = 0.0f;
     float maxScale = std::numeric_limits<float>::infinity();

include/mbgl/util/optional.hpp

@@ -0,0 +1,69 @@
+#ifndef MAPBOX_UTIL_OPTIONAL_HPP
+#define MAPBOX_UTIL_OPTIONAL_HPP
+
+#include <type_traits>
+
+#include "variant.hpp"
+
+namespace mapbox
+{
+namespace util
+{
+
+template <typename T> class optional
+{
+    static_assert(!std::is_reference<T>::value, "optional doesn't support references");
+
+    struct none_type
+    {
+    };
+
+    variant<none_type, T> variant_;
+
+  public:
+    optional() = default;
+
+    optional(optional const &rhs)
+    {
+        if (this != &rhs)
+        { // protect against invalid self-assignment
+            variant_ = rhs.variant_;
+        }
+    }
+
+    optional(T const &v) { variant_ = v; }
+
+    explicit operator bool() const noexcept { return variant_.template is<T>(); }
+
+    T const &get() const { return variant_.template get<T>(); }
+    T &get() { return variant_.template get<T>(); }
+
+    T const &operator*() const { return this->get(); }
+    T operator*() { return this->get(); }
+
+    optional &operator=(T const &v)
+    {
+        variant_ = v;
+        return *this;
+    }
+
+    optional &operator=(optional const &rhs)
+    {
+        if (this != &rhs)
+        {
+            variant_ = rhs.variant_;
+        }
+        return *this;
+    }
+
+    template <typename... Args> void emplace(Args &&... args)
+    {
+        variant_ = T{std::forward<Args>(args)...};
+    }
+
+    void reset() { variant_ = none_type{}; }
+};
+}
+}
+
+#endif

include/mbgl/util/variant.hpp

@@ -4,7 +4,6 @@
 #include <utility>
 #include <typeinfo>
 #include <type_traits>
-#include <algorithm> // std::move/swap
 #include <stdexcept> // runtime_error
 #include <new> // operator new
 #include <cstddef> // size_t
@@ -515,22 +514,13 @@ public:
     VARIANT_INLINE variant(no_init)
         : type_index(detail::invalid_value) {}
 
+    // http://isocpp.org/blog/2012/11/universal-references-in-c11-scott-meyers
     template <typename T, class = typename std::enable_if<
-                         detail::is_valid_type<T, Types...>::value>::type>
-    VARIANT_INLINE explicit variant(T const& val) noexcept
-        : type_index(detail::value_traits<T, Types...>::index)
-    {
-        constexpr std::size_t index = sizeof...(Types) - detail::value_traits<T, Types...>::index - 1;
-        using target_type = typename detail::select_type<index, Types...>::type;
-        new (&data) target_type(val);
-    }
-
-    template <typename T, class = typename std::enable_if<
-                          detail::is_valid_type<T, Types...>::value>::type>
+                          detail::is_valid_type<typename std::remove_reference<T>::type, Types...>::value>::type>
     VARIANT_INLINE variant(T && val) noexcept
-        : type_index(detail::value_traits<T, Types...>::index)
+        : type_index(detail::value_traits<typename std::remove_reference<T>::type, Types...>::index)
     {
-        constexpr std::size_t index = sizeof...(Types) - detail::value_traits<T, Types...>::index - 1;
+        constexpr std::size_t index = sizeof...(Types) - detail::value_traits<typename std::remove_reference<T>::type, Types...>::index - 1;
         using target_type = typename detail::select_type<index, Types...>::type;
         new (&data) target_type(std::forward<T>(val)); // nothrow
     }
@@ -565,7 +555,7 @@ public:
     template <typename T>
     VARIANT_INLINE variant<Types...>& operator=(T && rhs) noexcept
     {
-        variant<Types...> temp(std::move(rhs));
+        variant<Types...> temp(std::forward<T>(rhs));
         swap(*this, temp);
         return *this;
     }

test/fixtures/fixture_log.hpp

@@ -3,8 +3,7 @@
 
 #include <mbgl/platform/log.hpp>
 #include <mbgl/util/noncopyable.hpp>
-
-#include <boost/optional.hpp>
+#include <mbgl/util/optional.hpp>
 
 #include <vector>
 #include <cstdarg>
@@ -17,11 +16,11 @@ public:
         inline LogMessage(EventSeverity severity, Event event, int64_t code, const std::string &msg)
             : severity(severity), event(event), code(code), msg(msg) {}
         inline LogMessage(EventSeverity severity, Event event, int64_t code)
-            : severity(severity), event(event), code(code) {}
+            : severity(severity), event(event), code(code), msg() {}
         inline LogMessage(EventSeverity severity, Event event, const std::string &msg)
-            : severity(severity), event(event), msg(msg) {}
+            : severity(severity), event(event), code(), msg(msg) {}
         inline LogMessage(EventSeverity severity, Event event)
-            : severity(severity), event(event) {}
+            : severity(severity), event(event), code(), msg() {}
 
         inline bool operator==(const LogMessage &rhs) const {
             return (!severity || !rhs.severity || severity.get() == rhs.severity.get()) &&
@@ -30,10 +29,10 @@ public:
                    (!msg || !rhs.msg || msg.get() == rhs.msg.get());
         }
 
-        const boost::optional<EventSeverity> severity;
-        const boost::optional<Event> event;
-        const boost::optional<int64_t> code;
-        const boost::optional<std::string> msg;
+        const mapbox::util::optional<EventSeverity> severity;
+        const mapbox::util::optional<Event> event;
+        const mapbox::util::optional<int64_t> code;
+        const mapbox::util::optional<std::string> msg;
 
         mutable bool checked = false;
     };

test/variant.cpp

@@ -4,13 +4,6 @@
 #include <mbgl/style/value.hpp>
 #include <mbgl/style/value_comparison.hpp>
 
-#pragma GCC diagnostic push
-#ifndef __clang__
-#pragma GCC diagnostic ignored "-Wunused-local-typedefs"
-#endif
-#include <boost/lexical_cast.hpp>
-#pragma GCC diagnostic pop
-
 using namespace mbgl;
 
 TEST(Variant, toString) {