Add make_hero utility functions to learn sample

Author: wravery

samples/learn/CMakeLists.txt

@@ -5,6 +5,7 @@ cmake_minimum_required(VERSION 3.15)
 
 add_subdirectory(schema)
 add_library(star_wars STATIC
+  HeroData.cpp
   DroidData.cpp
   HumanData.cpp
   QueryData.cpp

samples/learn/DroidData.cpp

@@ -1,8 +1,6 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License.
 
-#include "CharacterObject.h"
-
 #include "DroidData.h"
 
 #include "HumanData.h"
@@ -55,22 +53,7 @@ std::optional<std::vector<std::shared_ptr<object::Character>>> Droid::getFriends
 		friends_.end(),
 		result.begin(),
 		[](const auto& wpFriend) noexcept {
-			return std::visit(
-				[](const auto& hero) noexcept {
-					using hero_t = std::decay_t<decltype(hero)>;
-
-					if constexpr (std::is_same_v<std::weak_ptr<Human>, hero_t>)
-					{
-						return std::make_shared<object::Character>(
-							std::make_shared<object::Human>(hero.lock()));
-					}
-					else if constexpr (std::is_same_v<std::weak_ptr<Droid>, hero_t>)
-					{
-						return std::make_shared<object::Character>(
-							std::make_shared<object::Droid>(hero.lock()));
-					}
-				},
-				wpFriend);
+			return make_hero(wpFriend);
 		});
 	result.erase(std::remove_if(result.begin(),
 					 result.end(),

samples/learn/HeroData.cpp

@@ -0,0 +1,49 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+#include "HeroData.h"
+
+#include "DroidData.h"
+#include "HumanData.h"
+
+namespace graphql::learn {
+
+std::shared_ptr<object::Character> make_hero(const SharedHero& hero) noexcept
+{
+	return std::visit(
+		[](const auto& hero) noexcept {
+			using hero_t = std::decay_t<decltype(hero)>;
+
+			if constexpr (std::is_same_v<std::shared_ptr<Human>, hero_t>)
+			{
+				return std::make_shared<object::Character>(std::make_shared<object::Human>(hero));
+			}
+			else if constexpr (std::is_same_v<std::shared_ptr<Droid>, hero_t>)
+			{
+				return std::make_shared<object::Character>(std::make_shared<object::Droid>(hero));
+			}
+		},
+		hero);
+}
+
+std::shared_ptr<object::Character> make_hero(const WeakHero& hero) noexcept
+{
+	return std::visit(
+		[](const auto& hero) noexcept {
+			using hero_t = std::decay_t<decltype(hero)>;
+
+			if constexpr (std::is_same_v<std::weak_ptr<Human>, hero_t>)
+			{
+				return std::make_shared<object::Character>(
+					std::make_shared<object::Human>(hero.lock()));
+			}
+			else if constexpr (std::is_same_v<std::weak_ptr<Droid>, hero_t>)
+			{
+				return std::make_shared<object::Character>(
+					std::make_shared<object::Droid>(hero.lock()));
+			}
+		},
+		hero);
+}
+
+} // namespace graphql::learn

samples/learn/HeroData.h

@@ -17,6 +17,15 @@ class Human;
 using SharedHero = std::variant<std::shared_ptr<Human>, std::shared_ptr<Droid>>;
 using WeakHero = std::variant<std::weak_ptr<Human>, std::weak_ptr<Droid>>;
 
+namespace object {
+
+class Character;
+
+} // namespace object
+
+std::shared_ptr<object::Character> make_hero(const SharedHero& hero) noexcept;
+std::shared_ptr<object::Character> make_hero(const WeakHero& hero) noexcept;
+
 } // namespace graphql::learn
 
 #endif // HERODATA_H

samples/learn/HumanData.cpp

@@ -1,8 +1,6 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License.
 
-#include "CharacterObject.h"
-
 #include "HumanData.h"
 
 #include "DroidData.h"
@@ -54,22 +52,7 @@ std::optional<std::vector<std::shared_ptr<object::Character>>> Human::getFriends
 		friends_.end(),
 		result.begin(),
 		[](const auto& wpFriend) noexcept {
-			return std::visit(
-				[](const auto& hero) noexcept {
-					using hero_t = std::decay_t<decltype(hero)>;
-
-					if constexpr (std::is_same_v<std::weak_ptr<Human>, hero_t>)
-					{
-						return std::make_shared<object::Character>(
-							std::make_shared<object::Human>(hero.lock()));
-					}
-					else if constexpr (std::is_same_v<std::weak_ptr<Droid>, hero_t>)
-					{
-						return std::make_shared<object::Character>(
-							std::make_shared<object::Droid>(hero.lock()));
-					}
-				},
-				wpFriend);
+			return make_hero(wpFriend);
 		});
 	result.erase(std::remove_if(result.begin(),
 					 result.end(),

samples/learn/QueryData.cpp

@@ -23,22 +23,7 @@ std::shared_ptr<object::Character> Query::getHero(std::optional<Episode> episode
 
 	if (const auto itr = heroes_.find(episode); itr != heroes_.end())
 	{
-		result = std::visit(
-			[](const auto& hero) noexcept {
-				using hero_t = std::decay_t<decltype(hero)>;
-
-				if constexpr (std::is_same_v<std::shared_ptr<Human>, hero_t>)
-				{
-					return std::make_shared<object::Character>(
-						std::make_shared<object::Human>(hero));
-				}
-				else if constexpr (std::is_same_v<std::shared_ptr<Droid>, hero_t>)
-				{
-					return std::make_shared<object::Character>(
-						std::make_shared<object::Droid>(hero));
-				}
-			},
-			itr->second);
+		result = make_hero(itr->second);
 	}
 
 	return result;