C++17

C++17 (also called C++1z) is the informal name for the future revision of the C++ ISO/IEC standard. The specification for the C++17 revision is under development and "nearly feature-complete"^[1] to be finished in 2017.

Expected features

• Addition of a default text message for static_assert^[2]
• Addition of std::string_view, a non-owning reference to a character sequence or string-slice^[3]
• Removal of trigraphs^[4][5]
• Allow typename in a template template parameter^[6]
• New rules for auto deduction from braced-init-list^[7][8]
• std::uncaught_exceptions, as a replacement of std::uncaught_exception^[9][10]
• Nested namespace definition^[8][11]
• Attributes for namespaces and enumerators^[10][12]
• UTF-8 character literals^[10][13]
• Constant evaluation for all non-type template arguments^[10][14]
• Folding expressions^[10][15]
• New insertion functions for std::map and std::unordered_map^[16][17]
• Uniform container access^[17][18]
• Definition of "contiguous iterators"^[17][19]
• Removal of some deprecated types and functions like std::auto_ptr, std::random_shuffle or old function adaptors^[20][8]
• A file system library based on boost::filesystem^[21]
• Parallel versions of STL algorithms^[22]
• Additional mathematical special functions^[23]
• Most of Library Fundamentals TS I (e.g. std::optional, std::any)^[24][25]
• std::variant, a type-safe union container
• A compile-time static if with the form if constexpr(expression)
• Structured bindings, allowing auto [a, b] = getTwoReturnValues();
• Initializers in if and switch statements
• Guaranteed copy elision by compilers in some cases
• Some extensions on aligned memory allocation
• Template deduction of constructors, allowing pair(5.0, false) instead of pair<double,bool>(5.0, false)
• Inline variables, which allows the declaration of variables in header files

Next standard

• C++20^[26]

See also

• C++
• C++11
• C++14

References