C++11/14 Rocks. Clang Edition. Alex Korban

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1 C++11/14 Rocks Clang Edition Alex Korban 1

2 Contents Introduction 9 C++11 guiding principles... 9 Type Inference 11 auto Some things are still manual More than syntactic sugar Why else do we need it? Objection, Your Honor! Diving in Alittlebitofauto history decltype Side e ects declval auto, decltype -howaboutbothatonce? Lambda Expressions 22 Why do we need this thing? Return type Lambda parameters Lambda body Storing lambdas std::function to the rescue References to outside context

3 Closures Capturing in C Capturing by reference Default capture modes Capturing class members Limitations of capturing Mutable lambdas Conversion to function pointers, nested lambdas, recursion How not to shoot yourself in the foot Rules of thumb for lambdas Lambda syntax in all its glory Template Features 39 Variadic templates What else are variadic templates good for? Back to the example Working with parameter packs Traversing template parameter packs Constraining parameter packs to one type More places to expand a parameter pack Nested variadic templates Multiple parameter packs in function templates, non-type parameter packs 46 Template aliases Using using instead of typedef Closing angle brackets are o cially allowed to tail-gate Local and unnamed types as template arguments extern templates Default values for function template parameters Arbitrary expressions in template deduction contexts

4 Class Features 55 In-class initializers for non-static data members Inheriting constructors Delegating constructors Default methods Deleted methods override and final Extended friend declarations Nested class access rights The Dream of Uniform Initialization 72 Embrace the braces initializer_list Narrowing conversions Distortions of the uniformity continuum Want a move-only type in your vector? auto + {} <> + {} =? Surprising consequences of narrowing What s the verdict? Move Semantics 82 What are the benefits? How does this stu work? Revision part 1: lvalue vs. rvalue Revision part 2: const attribute + lvalue/rvalue Revision part 3: reference initialization Rvalue references

5 Overload resolution Implementing move semantics Compiler generated move operations Implementing your own move operations std::move Moving it right Rvalue references to const values Derived class construction Move construction in terms of assignment Check for self-assignment Don t make move constructors explicit Reference qualifiers for member functions Move-only types Perfect Forwarding Problem and Solution 103 Reference collapsing and rvalues in templates How the forward template works Bonus: implementation of std::move constexpr Mechanism 111 What else is it good for? What s in a constant expression? constexpr variables const and constexpr constexpr functions Literal types Acouplemorenotesonconstexpr functions Range-based for Loop 117 5

6 nullptr 120 What s the advantage over NULL? enum Changes 122 Scoped enums Specifying the underlying type Forward declaration Compile Time Assertions 127 Literals 129 Unicode support and literals Unicode character literals Raw literals User defined literals Types of literals Literal operators for integers Character and string literal operators noexcept 140 noexcept for your own functions noexcept operator When to use noexcept Acouplemorenotesonnoexcept Explicit Conversion Operators 144 Inline Namespaces 145 Why not just add a using statement?

7 Alignment 148 alignof alignas sizeof Applied to Non-static Data Members 150 Memory Model 151 Multi-threading related semantics Thread local storage 152 Thread local initialization Thread local destruction Attributes 155 Standard attributes POD Types, Trivial Types, and Standard Layout Types 157 Trivial classes Trivially copyable classes Trivial operations Standard layout types and classes Changed restrictions on unions Discriminated unions C99 Compatibility Features 165 Deprecated and Removed Features 166 C Return type deduction for functions Redeclaration

8 Generic lambdas Extended capturing in lambdas Revised restrictions on constexpr functions constexpr variable templates decltype(auto) Literals [[deprecated]] attribute Aggregate initialization Beyond C Writing Cross-Platform Code 176 Conclusion 178 Contact Information and License Agreement 179 License agreement

C++11/14 Rocks. VS2013 Edition. Alex Korban

C++11/14 Rocks. VS2013 Edition. Alex Korban C++11/14 Rocks VS2013 Edition Alex Korban 1 Contents Introduction 18 Type Inference 20 auto... 20 decltype... 24 Side e ects... 25 Trailing return types... 26 Non-standard behavior and bugs in Visual Studio