/*
- * Copyright 2017 Facebook, Inc.
+ * Copyright 2012-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.
#include <folly/Conv.h>
#include <folly/Optional.h>
+#include <folly/functional/Invoke.h>
#include <tuple>
namespace folly {
* Given a map and a key, return the value corresponding to the key in the map,
* or a given default value if the key doesn't exist in the map.
*/
-template <class Map, typename Key = typename Map::key_type>
-typename Map::mapped_type get_default(
- const Map& map,
- const Key& key,
- const typename Map::mapped_type& dflt = typename Map::mapped_type()) {
+template <typename Map, typename Key>
+typename Map::mapped_type get_default(const Map& map, const Key& key) {
auto pos = map.find(key);
- return (pos != map.end() ? pos->second : dflt);
+ return (pos != map.end()) ? (pos->second) : (typename Map::mapped_type{});
+}
+template <
+ class Map,
+ typename Key = typename Map::key_type,
+ typename Value = typename Map::mapped_type,
+ typename std::enable_if<!is_invocable<Value>::value>::type* = nullptr>
+typename Map::mapped_type
+get_default(const Map& map, const Key& key, Value&& dflt) {
+ using M = typename Map::mapped_type;
+ auto pos = map.find(key);
+ return (pos != map.end()) ? (pos->second) : M(std::forward<Value>(dflt));
}
/**
typename DefaultType<KeysDefault...>::type const& {
return std::get<sizeof...(KeysDefault)-1>(std::tie(keysDefault...));
}
-}
+} // namespace detail
/**
* Given a map of maps and a path of keys, return a pointer to the nested value,
}
return detail::extract_default(keysDefault...);
}
-} // namespace folly
+} // namespace folly