set_map_service( const std::shared_ptr request, std::shared_ptr response); void generate_path_service( const std::shared_ptr request, std::shared_ptr response); bool set_costmap(const std_msgs::msg::UInt8MultiArray& costmap); Path generate_global_path(Position set_map_service( const std::shared_ptr request, std::shared_ptr response); void generate_path_service( const std::shared_ptr

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www.ModernesCpp.netSmart Pointer A First Overview std::unique_ptr – Exclusive Ownership std::shared_ptr – Shared Ownership std::weak_ptr – Break of Cyclic References Performance Concurrency Function Arguments and Return ValuesSmart Pointer A First Overview std::unique_ptr – Exclusive Ownership std::shared_ptr – Shared Ownership std::weak_ptr – Break of Cyclic References Performance Concurrency Function C++11 ▪ Owns the resource exclusively ▪ Can not be copied ▪ Deals with non-copy objects std::shared_ptr C++11 ▪ Shares a resource ▪ Supports an reference counter to the shared resource and manages it

Reference Counting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 5.2 std::shared_ptr . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 5.3 std::unique_ptr mers no longer need to care about manually releasing memory. These smart pointers include std::shared_ptr/std::unique_ptr/std::weak_ptr, which need to include the header file . Note: The reference of resources. 57 5.2 std::shared_ptr CHAPTER 05 SMART POINTERS AND MEMORY MANAGEMENT 5.2 std::shared_ptr std::shared_ptr is a smart pointer that records how many shared_ptr points to an object, elimi-

interface name using LoaderType = pluginlib::ClassLoader std::shared_ptr loader = std::make_shared("package_name"); // In ROS world plugin name which is declared in the XML file. Maybe we send the derived class name? std::shared_ptr motion_planner = loader->createUniqueInstance("simple_motion_planner"); the interface name using LoaderType = pluginlib::ClassLoader std::shared_ptr loader = std::make_shared("package_name"); // In ROS world

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 5.2 std::shared_ptr . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 5.3 std::unique_ptr 增加一次对同一个对象的引用，那 么引用对象的引用计数就会增加一次，每删除一次引用，引用计数就会减一，当一个对象的引用计数减 为零时，就自动删除指向的堆内存。 52 5.2 std::shared_ptr 第 5 章智能指针与内存管理 在传统 C++ 中，『记得』手动释放资源，总不是最佳实践。因为我们很有可能就忘记了去释放资源 而导致泄露。所以通常的做法是对于一个对象而言，我们在构造函数的时候申请空间，而在析构函数（在 员不再需要关心手动释放内存。这些智能指针包括 std::shared_ptr/std::unique_ptr/std::weak_ptr， 使用它们需要包含头文件 。 注意：引用计数不是垃圾回收，引用计数能够尽快收回不再被使用的对象，同时在回收的过 程中也不会造成长时间的等待，更能够清晰明确的表明资源的生命周期。 5.2 std::shared_ptr std::shared_ptr 是一种智能指针，它能够记录多少个

*o << " prints 9\n"; • views::nullable — Extra safety for maybe-like types — std::optional, shared_ptr, raw ptrs, result of find (?)© 2018 Bloomberg Finance L.P. All rights reserved. How does this *o << " prints 9\n"; • views::nullable — Extra safety for maybe-like types — std::optional, shared_ptr, raw ptrs, result of find (?) • Give us the basis to implement anything! p1255: A view of 0 out; 15: } and_then • views::nullable — Extra safety for maybe-like types — std::optional, shared_ptr, raw ptrs, result of find (?) p1255: A view of 0 or 1 elements: views::maybe by Steve Downey

save a second or two Speaker notesORIGINAL NODE SORTING CODE struct Node; using NodePtr = std::shared_ptr; struct Prefab { uint64_t GetId() const; std::vector nodes_; }; struct Node primitive • Result: 100% CPU usage for many minutes SpinLock data_save_lock; void Process(std::shared_ptr data) { data->Processing(); { SpinLockGuard guard(data_save_lock); data->SaveFile(); std::mutex data_save_lock; std::lock_guard guard(data_save_lock); 1 2 void Process(std::shared_ptr data) 3 { 4 data->Processing(); 5 6 { 7 8 data->SaveFile(); 9 } 10 } 11 39To verify

std::atomicshared_ptr> g_config; void setDefaultHostname(const std::string& value) { std::shared_ptr blue = g_config.load(); do { std::shared_ptr std::map; std::atomicshared_ptr> g_config; // ... std::shared_ptr getDefaultHostname() { std::shared_ptr blue = g_config.load(); load(); const std::string& value = blue.at("default.hostname"); return std::shared_ptr(std::move(blue), &value); } 50 “Aliasing constructor” alert! The blue ConfigMap will stay

() {} void Init(const S3ClientAdaptorOption option, S3Client *client, std::shared_ptr inodeManager);© XXX Page 5 of 9 int Write(Inode *inode, uint64_t offset, uint64_t allocateServerEps_; Thread bgFlushThread_; std::atomic toStop_; std::shared_ptr fsCacheManager_; std::shared_ptr inodeManager_; }; class S3ClientAdaptor; class ChunkCacheManager; class FileCacheManager; class FsCacheManager; using FileCacheManagerPtr = std::shared_ptr; using ChunkCacheManagerPtr = std::shared_ptr; using DataCachePtr = std::shared_ptr; class FsCacheManager { public: FsCacheManager()

template> class unique_ptr {...};The custom deleter for shared_ptr and unique_ptr are di�erent We’re used to this construct of a smart pointer: But this will cause not delete Where D is a (dangerous!) custom deleter de�ned by: shared_ptr my_ptr = rhs; unique_ptr my_uniqueptr = rhs; shared_ptr my_sharedptr(ref,D); template struct no_deleter { operator operator () (T* ptr) { // do nothing } }The custom deleter for shared_ptr and unique_ptr are di�erent We’re used to this construct of a smart pointer: But this will cause a ‘delete’ when the scope