Modern C++ Design. Generic Programming and Design Patterns Applied. Andrei Alexandrescu. AAddison-Wesley

Transcription

1 Modern C++ Design Generic Programming and Design Patterns Applied Andrei Alexandrescu f AAddison-Wesley Boston San Francisco New York Toronto Montreal London Munich Paris Madrid Capetown Sydney Tokyo Singapore Mexico City

2 Contents 1 Foreword by Scott Meyers Foreword by John Vlissides Preface Acknowledgments xi XV xvii xxi Parti Chapter Techniques Policy-Based Class Design The Multiplicity of Software Design The Failure of the Do-It-All Interface Multiple Inheritance to the Rescue? The Benefit of Templates Policies and Policy Classes Enriched Policies Destructors of Policy Classes Optional Functionality Through Incomplete Instantiation Combining Policy Classes Customizing Structure with Policy Classes Compatible and Incompatible Policies Decomposing a Class into Policies

3 vi Contents Chapter Chapter i Д Chapter Techniques Compile-Time Assertions Partial Template Specialization Local Classes Mapping Integral Constants to Types Type-to-Type Mapping Type Selection Detecting Convertibility and Inheritance at Compile Time A Wrapper Around type_i nf о NullType and EmptyType Type Traits Typelists The Need for Typelists Defining Typelists Linearizing Typelist Creation Calculating Length Intermezzo Indexed Access Searching Typelists Appending to Typelists Erasing a Type from a Typelist Erasing Duplicates Replacing an Element in a Typelist Partially Ordering Typelists Class Generation with Typelists Typel i st Quick Facts Small-Object Allocation The Default Free Store Allocator The Workings of a Memory Allocator A Small-Object Allocator Chunks The Fixed-Size Allocator The SmallObjAllocator Class A Hat Trick Simple, Complicated, Yet Simple in the End Administrivia Small-Object Allocator Quick Facts

4 Contents vii Part II Chapter Chapter Chapter Components Generalized Functors The Command Design Pattern Command in the Real World C++ Callable Entities The Functor Class Template Skeleton Implementing the Forwarding Functor: :operator() Handling Functors Build One, Get One Free Argument and Return Type Conversions Handling Pointers to Member Functions Binding Chaining Requests Real-World Issues I: The Cost of Forwarding Functions Real-World Issues II: Heap Allocation Implementing Undo and Redo with Functor Functor Quick Facts Implementing Singletons Static Data + Static Functions!= Singleton The Basic C++ Idioms Supporting Singleton Enforcing the Singleton's Uniqueness Destroying the Singleton The Dead Reference Problem Addressing the Dead Reference Problem (I): The Phoenix Singleton Addressing the Dead Reference Problem (II): Singletons with Longevity Implementing Singletons with Longevity Living in a Multithreaded World Putting It All Together Working with Sing! etonhol der Si ngl etonhol der Class Template Quick Facts Smart Pointers Smart Pointers 101 The Deal Storage of Smart Pointers Smart Pointer Member Functions

5 viii Contents 7.5 Ownership-Handling Strategies The Address-of Operator Implicit Conversion to Raw Pointer Types Equality and Inequality Ordering Comparisons Checking and Error Reporting Smart Pointers to const and const Smart Pointers Arrays Smart Pointers and Multithreading Putting It All Together SmartPtr Quick Facts 194 Chapter 8 Object Factories The Need for Object Factories Object Factories in C++: Classes and Objects Implementing an Object Factory Type Identifiers Generalization Minutiae Clone Factories Using Object Factories with Other Generic Components Factory Class Template Quick Facts CIoneFactory Class Template Quick Facts 217 Chapter 9 Abstract Factory The Architectural Role of Abstract Factory A Generic Abstract Factory Interface Implementing AbstractFactory A Prototype-Based Abstract Factory Implementation AbstractFactory and ConcreteFactory Quick Facts 233 Chapter 10 Visitor Visitor Basics Overloading and the Catch-All Function An Implementation Refinement: The Acyclic Visitor A Generic Implementation of Visitor Back to the "Cyclic" Visitor Hooking Variations Visitor Generic Component Quick Facts 261

6 Contents ix Chapter 11 Multimethods 11.1 What Are Multimethods? 11.2 When Are Multimethods Needed? 11.3 Double Switch-on-Type: Brute Force 11.4 The Brute-Force Approach Automated 11.5 Symmetry with the Brute-Force Dispatcher 11.6 The Logarithmic Double Dispatcher 11.7 FnDi spatcher and Symmetry 11.8 Double Dispatch to Functors 11.9 Converting Arguments: stati c_cast or dynami c_cast? Constant-Time Multimethods: Raw Speed BasicDispatcher and BasicFastDispatcher as Policies Looking Forward Double Dispatcher Quick Facts Appendix A.l A.2 A.3 A.4 A.5 A.6 A.7 A.8 Bibliography Index A Minimalist Multithreading Library A Critique of Multithreading Loki's Approach Atomic Operations on Integral Types Mutexes Locking Semantics in Object-Oriented Programming Optional vol ati 1 e Modifier Semaphores, Events, and Other Good Things