Easy: store metadata with SettingsCore object

Summary: Requires a new header to break the circular dependency

Differential Revision: D9983196

fbshipit-source-id: f15ab3c6128d30906ac25384df92813aa9d76c9a

folly/experimental/settings/Settings.h

@@ -19,47 +19,11 @@
 #include <string>
 
 #include <folly/Range.h>
+#include <folly/experimental/settings/SettingsMetadata.h>
 #include <folly/experimental/settings/detail/SettingsImpl.h>
 
 namespace folly {
 namespace settings {
-
-/**
- * Static information about the setting definition
- */
-struct SettingMetadata {
-  /**
-   * Project string.
-   */
-  folly::StringPiece project;
-
-  /**
-   * Setting name within the project.
-   */
-  folly::StringPiece name;
-
-  /**
-   * String representation of the type.
-   */
-  folly::StringPiece typeStr;
-
-  /**
-   * typeid() of the type.
-   */
-  const std::type_info& typeId;
-
-  /**
-   * String representation of the default value.
-   * (note: string literal default values will be stringified with quotes)
-   */
-  folly::StringPiece defaultStr;
-
-  /**
-   * Setting description field.
-   */
-  folly::StringPiece description;
-};
-
 namespace detail {
 
 template <class T>
@@ -99,11 +63,9 @@ class Setting {
       SettingMetadata meta,
       T defaultValue,
       std::atomic<uint64_t>& trivialStorage)
-      : meta_(std::move(meta)),
-        core_(meta_, std::move(defaultValue), trivialStorage) {}
+      : core_(std::move(meta), std::move(defaultValue), trivialStorage) {}
 
  private:
-  SettingMetadata meta_;
   SettingCore<T> core_;
 };
 

folly/experimental/settings/SettingsMetadata.h

+/*
+ * Copyright 2018-present Facebook, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#pragma once
+
+#include <folly/Range.h>
+
+namespace folly {
+namespace settings {
+
+/**
+ * Static information about the setting definition
+ */
+struct SettingMetadata {
+  /**
+   * Project string.
+   */
+  folly::StringPiece project;
+
+  /**
+   * Setting name within the project.
+   */
+  folly::StringPiece name;
+
+  /**
+   * String representation of the type.
+   */
+  folly::StringPiece typeStr;
+
+  /**
+   * typeid() of the type.
+   */
+  const std::type_info& typeId;
+
+  /**
+   * String representation of the default value.
+   * (note: string literal default values will be stringified with quotes)
+   */
+  folly::StringPiece defaultStr;
+
+  /**
+   * Setting description field.
+   */
+  folly::StringPiece description;
+};
+
+} // namespace settings
+} // namespace folly

folly/experimental/settings/detail/SettingsImpl.h

@@ -25,12 +25,10 @@
 #include <folly/Range.h>
 #include <folly/SharedMutex.h>
 #include <folly/ThreadLocal.h>
+#include <folly/experimental/settings/SettingsMetadata.h>
 
 namespace folly {
 namespace settings {
-
-struct SettingMetadata;
-
 namespace detail {
 
 /**
@@ -130,10 +128,10 @@ class SettingCore : public SettingCoreBase {
   }
 
   SettingCore(
-      const SettingMetadata& meta,
+      SettingMetadata meta,
       T defaultValue,
       std::atomic<uint64_t>& trivialStorage)
-      : meta_(meta),
+      : meta_(std::move(meta)),
         defaultValue_(std::move(defaultValue)),
         trivialStorage_(trivialStorage),
         localValue_([]() {
@@ -146,7 +144,7 @@ class SettingCore : public SettingCoreBase {
   }
 
  private:
-  const SettingMetadata& meta_;
+  SettingMetadata meta_;
   const T defaultValue_;
 
   SharedMutex globalLock_;