Preface xxiii
Acknowledgments for the Second Edition xxv
Acknowledgments for the First Edition xxvii
About This Book xxix
Part I: The Basics 1
Chapter 1: Function Templates 3
1.1 A First Look at Function Templates 3
1.2 Template Argument Deduction 7
1.3 Multiple Template Parameters 9
1.4 Default Template Arguments 13
1.5 Overloading Function Templates 15
1.6 But, Shouldn't We . . . ? 20
1.7 Summary 21
Chapter 2: Class Templates 23
2.1 Implementation of Class Template Stack 23
2.2 Use of Class Template Stack 27
2.3 Partial Usage of Class Templates 29
2.4 Friends 30
2.5 Specializations of Class Templates 31
2.6 Partial Specialization 33
2.7 Default Class Template Arguments 36
2.8 Type Aliases38
2.9 Class Template Argument Deduction 40
2.10 Templatized Aggregates 43
2.11 Summary 44
Chapter 3: Nontype Template Parameters 45
3.1 Nontype Class Template Parameters 45
3.2 Nontype Function Template Parameters 48
3.3 Restrictions for Nontype Template Parameters 49
3.4 Template Parameter Type auto 50
3.5 Summary 54
Chapter 4: Variadic Templates 55
4.1 Variadic Templates 55
4.2 Fold Expressions 58
4.3 Application of Variadic Templates 60
4.4 Variadic Class Templates and Variadic Expressions 61
4.5 Summary 66
Chapter 5: Tricky Basics 67
5.1 Keyword typename 67
5.2 Zero Initialization 68
5.3 Using this-> 70
5.4 Templates for Raw Arrays and String Literals 71
5.5 Member Templates 74
5.6 Variable Templates 80
5.7 Template Template Parameters 83
5.8 Summary 89
Chapter 6: Move Semantics and enable_if<> 91
6.1 Perfect Forwarding 91
6.2 Special Member Function Templates 95
6.3 Disable Templates with enable_if<> 98
6.4 Using enable_if<> 99
6.5 Using Concepts to Simplify enable_if<> Expressions 103
6.6 Summary 104
Chapter 7: By Value or by Reference? 105
7.1 Passing by Value 106
7.2 Passing by Reference 108
7.3 Using std::ref() and std::cref() 112
7.4 Dealing with String Literals and Raw Arrays 115
7.5 Dealing with Return Values 117
7.6 Recommended Template Parameter Declarations 118
7.7 Summary 121
Chapter 8: Compile-Time Programming 123
8.1 Template Metaprogramming 123
8.2 Computing with constexpr 125
8.3 Execution Path Selection with Partial Specialization 127
8.4 SFINAE (Substitution Failure Is Not An Error) 129
8.5 Compile-Time if 134
8.6 Summary 135
Chapter 9: Using Templates in Practice 137
9.1 The Inclusion Model 137
9.2 Templates and inline 140
9.3 Precompiled Headers 141
9.4 Decoding the Error Novel 143
9.5 Afternotes 149
9.6 Summary 150
Chapter 10: Basic Template Terminology 151
10.1 Class Template or Template Class? 151
10.2 Substitution, Instantiation, and Specialization 152
10.3 Declarations versus Definitions 153
10.4 The One-Definition Rule 154
10.5 Template Arguments versus Template Parameters 155
10.6 Summary 156
Chapter 11: Generic Libraries 157
11.1 Callables 157
11.2 Other Utilities to Implement Generic Libraries 164
11.3 Perfect Forwarding Temporaries 167
11.4 References as Template Parameters 167
11.5 Defer Evaluations 171
11.6 Things to Consider When Writing Generic Libraries 172
11.7 Summary 173
Part II: Templates in Depth 175
Chapter 12: Fundamentals in Depth 177
12.1 Parameterized Declarations 177
12.2 Template Parameters 185
12.3 Template Arguments 192
12.4 Variadic Templates 200
12.5 Friends 209
12.6 Afternotes 213
Chapter 13: Names in Templates 215
13.1 Name Taxonomy 215
13.2 Looking Up Names 217
13.3 Parsing Templates 224
13.4 Inheritance and Class Templates 236
13.5 Afternotes 240
Chapter 14: Instantiation 243
14.1 On-Demand Instantiation 243
14.2 Lazy Instantiation 245
14.3 The C++ Instantiation Model 249
14.4 Implementation Schemes 255
14.5 Explicit Instantiation 260
14.6 Compile-Time if Statements 263
14.7 In the Standard Library 265
14.8 Afternotes 266
Chapter 15: Template Argument Deduction 269
15.1 The Deduction Process 269
15.2 Deduced Contexts 271
15.3 Special Deduction Situations 273
15.4 Initializer Lists 274
15.5 Parameter Packs 275
15.6 Rvalue References 277
15.7 SFINAE (Substitution Failure Is Not An Error) 284
15.8 Limitations of Deduction 286
15.9 Explicit Function Template Arguments 291
15.10 Deduction from Initializers and Expressions 293
15.11 Alias Templates 312
15.12 Class Template Argument Deduction 313
15.13 Afternotes 321
Chapter 16: Specialization and Overloading 323
16.1 When Generic Code Doesn't Quite Cut It 323
16.2 Overloading Function Templates 326
16.3 Explicit Specialization 338
16.4 Partial Class Template Specialization 347
16.5 Partial Variable Template Specialization 351
16.6 Afternotes 352
Chapter 17: Future Directions 353
17.1 Relaxed typename Rules 354
17.2 Generalized Nontype Template Parameters 354
17.3 Partial Specialization of Function Templates 356
17.4 Named Template Arguments 358
17.5 Overloaded Class Templates 359
17.6 Deduction for Nonfinal Pack Expansions 360
17.7 Regularization of void 361
17.8 Type Checking for Templates 361
17.9 Reflective Metaprogramming 363
17.10 Pack Facilities 365
17.11 Modules 366
Part III: Templates and Design 367
Chapter 18: The Polymorphic Power of Templates 369
18.1 Dynamic Polymorphism 369
18.2 Static Polymorphism 372
18.3 Dynamic versus Static Polymorphism 375
18.4 Using Concepts 377
18.5 New Forms of Design Patterns 379
18.6 Generic Programming 380
18.7 Afternotes 383
Chapter 19: Implementing Traits 385
19.1 An Example: Accumulating a Sequence 385
19.2 Traits versus Policies and Policy Classes 394
19.3 Type Functions 401
19.4 SFINAE-Based Traits 416
19.5 IsConvertibleT 428
19.6 Detecting Members 431
19.7 Other Traits Techniques 440
19.8 Type Classification 448
19.9 Policy Traits 458
19.10 In the Standard Library 461
19.11 Afternotes 462
Chapter 20: Overloading on Type Properties 465
20.1 Algorithm Specialization 465
20.2 Tag Dispatching 467
20.3 Enabling/Disabling Function Templates 469
20.4 Class Specialization 477
20.5 Instantiation-Safe Templates 482
20.6 In the Standard Library 487
20.7 Afternotes 488
Chapter 21: Templates and Inheritance 489
21.1 The Empty Base Class Optimization (EBCO) 489
21.2 The Curiously Recurring Template Pattern (CRTP) 495
21.3 Mixins 508
21.4 Named Template Arguments 512
21.5 Afternotes 515
Chapter 22: Bridging Static and Dynamic Polymorphism 517
22.1 Function Objects, Pointers, and std::function<> 517
22.2 Generalized Function Pointers 519
22.3 Bridge Interface 522
22.4 Type Erasure 523
22.5 Optional Bridging 525
22.6 Performance Considerations 527
22.7 Afternotes 528
Chapter 23: Metaprogramming 529
23.1 The State of Modern C++ Metaprogramming 529
23.2 The Dimensions of Reflective Metaprogramming 537
23.3 The Cost of Recursive Instantiation 539
23.4 Computational Completeness 542
23.5 Recursive Instantiation versus Recursive Template Arguments 542
23.6 Enumeration Values versus Static Constants 543
23.7 Afternotes 545
Chapter 24: Typelists 549
24.1 Anatomy of a Typelist 549
24.2 Typelist Algorithms 551
24.3 Nontype Typelists 566
24.4 Optimizing Algorithms with Pack Expansions 569
24.5 Cons-style Typelists 571
24.6 Afternotes 573
Chapter 25: Tuples 575
25.1 Basic Tuple Design 576
25.2 Basic Tuple Operations 579
25.3 Tuple Algorithms 581
25.4 Expanding Tuples 592
25.5 Optimizing Tuple 593
25.6 Tuple Subscript 599
25.7 Afternotes 601
Chapter 26: Discriminated Unions 603
26.1 Storage 604
26.2 Design 606
26.3 Value Query and Extraction 610
26.4 Element Initialization, Assignment and Destruction 611
26.5 Visitors 617
26.6 Variant Initialization and Assignment 624
26.7 Afternotes 628
Chapter 27: Expression Templates 629
27.1 Temporaries and Split Loops 630
27.2 Encoding Expressions in Template Arguments 635
27.3 Performance and Limitations of Expression Templates 646
27.4 Afternotes 647
Chapter 28: Debugging Templates 651
28.1 Shallow Instantiation 652
28.2 Static Assertions 654
28.3 Archetypes 655
28.4 Tracers 657
28.5 Oracles 662
28.6 Afternotes 662
Appendixes 663
Appendix A: The One-Definition Rule 663
A.1 Translation Units 663
A.2 Declarations and Definitions 664
A.3 The One-Definition Rule in Detail 665
Appendix B: Value Categories 673
B.1 Traditional Lvalues and Rvalues 673
B.2 Value Categories Since C++11 674
B.3 Checking Value Categories with decltype 678
B.4 Reference Types 679
Appendix C: Overload Resolution 681
C.1 When Does Overload Resolution Kick In? 681
C.2 Simplified Overload Resolution 682
C.3 Overloading Details 688
Appendix D: Standard Type Utilities 697
D.1 Using Type Traits 697
D.2 Primary and Composite Type Categories 702
D.3 Type Properties and Operations 709
D.4 Type Construction 728
D.5 Other Traits 732
D.6 Combining Type Traits 734
D.7 Other Utilities 737
Appendix E: Concepts 739
E.1 Using Concepts 739
E.2 Defining Concepts 742
E.3 Overloading on Constraints 743
E.4 Concept Tips 746
Bibliography 749
Glossary 759
Index 771
