Replace boost::optional with std::optional (#4877)

src/providers/bttv/BttvEmotes.hpp

@@ -3,9 +3,8 @@
 #include "common/Aliases.hpp"
 #include "common/Atomic.hpp"
 
-#include <boost/optional.hpp>
-
 #include <memory>
+#include <optional>
 
 namespace chatterino {
 
@@ -27,7 +26,7 @@ public:
     BttvEmotes();
 
     std::shared_ptr<const EmoteMap> emotes() const;
-    boost::optional<EmotePtr> emote(const EmoteName &name) const;
+    std::optional<EmotePtr> emote(const EmoteName &name) const;
     void loadEmotes();
     void setEmotes(std::shared_ptr<const EmoteMap> emotes);
     static void loadChannel(std::weak_ptr<Channel> channel,
@@ -55,7 +54,7 @@ public:
      *
      * @return pair<old emote, new emote> if any emote was updated.
      */
-    static boost::optional<std::pair<EmotePtr, EmotePtr>> updateEmote(
+    static std::optional<std::pair<EmotePtr, EmotePtr>> updateEmote(
         const QString &channelDisplayName,
         Atomic<std::shared_ptr<const EmoteMap>> &channelEmoteMap,
         const BttvLiveUpdateEmoteUpdateAddMessage &message);
@@ -67,7 +66,7 @@ public:
      *
      * @return The removed emote if any emote was removed.
      */
-    static boost::optional<EmotePtr> removeEmote(
+    static std::optional<EmotePtr> removeEmote(
         Atomic<std::shared_ptr<const EmoteMap>> &channelEmoteMap,
         const BttvLiveUpdateEmoteRemoveMessage &message);