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C++17

From cppreference.com
< cpp

C++17 is a major version that follows the minor version C++14 and introduces new language and library features. The standard was published in December 2017.

The following features were merged into C++17:

Contents

[edit] Obsolete

[edit] Removed:
[edit] Deprecated:

[edit] New language features

[edit] New headers

[edit] New library features

[edit] Utility types

[edit] Memory management

[edit] Compile-time programming

[edit] Algorithms

[edit] Iterators and containers

[edit] Numerics

[edit] Others

[edit] Defect reports

Defect Reports fixed in C++17 (290 core, 363 library)

[edit] Compiler support

[edit] C++17 core language features

C++17 feature

 
Paper(s)

 
GCC
Clang
MSVC
Apple Clang
EDG eccp
Intel C++
Nvidia HPC C++ (ex PGI)*
Nvidia nvcc
Cray
 
Embarcadero C++ Builder
IBM Open XL C++ for AIX
DR11: New auto rules for direct-list-initialization N3922 5 3.8 19.0 (2015)* Yes 4.10.1 17.0 17.7 11.0 11.0  10.3 17.1.0
static_assert with no message N3928 6 2.5 19.10* Yes 4.12 18.0 17.7 11.0 11.0  10.3 17.1.0
typename in a template template parameter N4051 5 3.5 19.0 (2015)* Yes 4.10.1 17.0 17.7 Yes* 11.0  10.3 17.1.0
Removing trigraphs N4086 5 3.5 16.0* Yes 5.0 19.1 11.0 11.0  10.3 17.1.0
Nested namespace definition N4230 6 3.6 19.0 (Update 3)* Yes 4.12 17.0 17.7 11.0 11.0  10.3 17.1.0
Attributes for namespaces and enumerators N4266 4.9 (partial)*
6
3.6 19.0 (2015)* Yes 4.11 17.0 17.7 11.0 11.0  10.3 17.1.0
u8 character literals N4267 6 3.6 19.0 (2015)* Yes 4.11 17.0 17.7 11.0 11.0  10.3 17.1.0
Allow constant evaluation for all non-type template arguments N4268 6 3.6 19.12* Yes 5.0 19.0.1 19.1 11.0 11.0  10.3 17.1.0
Fold Expressions N4295 6 3.6 19.12* Yes 4.14 19.0 18.1 11.0 11.0  10.3 17.1.0
Unary fold expressions and empty parameter packs P0036R0 6 3.9 19.12* Yes 4.14 19.0 19.1 11.0 11.0  10.3 17.1.0
Remove Deprecated Use of the register Keyword P0001R1 7 3.8 19.11* Yes 4.13 18.0 17.7 11.0 11.0  10.3 17.1.0
Remove Deprecated operator++(bool) P0002R1 7 3.8 19.11* Yes 4.13 18.0 17.7 11.0 11.0  10.3 17.1.0
Make exception specifications part of the type system P0012R1 7 4 19.12* Yes 4.14 19.0 19.1 11.0 11.0  10.3 17.1.0
Aggregate classes with base classes P0017R1 7 3.9 19.14* Yes 5.0 19.0.1 19.1 11.0 11.0  10.3 17.1.0
__has_include in preprocessor conditionals P0061R1 5 Yes 19.11* Yes 4.13 18.0 17.7 11.0 11.0  10.3 17.1.0
DR11: New specification for inheriting constructors (DR1941 et al) P0136R1 7 3.9 19.14 (partial)* Yes 6.1 19.1 11.0 11.0  10.3 17.1.0
Lambda capture of *this P0018R3 7 3.9 19.11* Yes 4.14 19.0 18.1 11.0 11.0  10.3 17.1.0
Direct-list-initialization of enumerations P0138R2 7 3.9 19.11* Yes 4.14 18.0 19.1 11.0 11.0  10.3 17.1.0
constexpr lambda expressions P0170R1 7 5 19.11* Yes 4.14 19.0 18.1 11.0 11.0  10.3 17.1.0
Differing begin and end types in range-based for P0184R0 6 3.9 19.10* Yes 4.12 18.0 17.7 11.0 11.0  10.3 17.1.0
[[fallthrough]] attribute P0188R1 7 3.9 19.10* Yes 4.13 18.0 17.7 11.0 11.0  10.3 17.1.0
[[nodiscard]] attribute P0189R1 7 3.9 19.11* Yes 4.13 18.0 17.7 11.0 11.0  10.3 17.1.0
[[maybe_unused]] attribute P0212R1 7 3.9 19.11* Yes 4.13 18.0 17.7 11.0 11.0  10.3 17.1.0
Hexadecimal floating-point literals P0245R1 3.0 Yes 19.11* Yes 4.13 18.0 17.7 11.0 11.0  10.3 17.1.0
Using attribute namespaces without repetition P0028R4 7 3.9 19.11* Yes 4.13 18.0 17.7 11.0 11.0  10.3 17.1.0
Dynamic memory allocation for over-aligned data P0035R4 7 4 19.12* 10.0.0* 4.14 19.0 19.1 11.0 11.0  10.3 17.1.0
Class template argument deduction P0091R3 7 5 19.14* Yes 5.0 19.0.1 19.1 11.0 11.0  10.3 17.1.0
Non-type template parameters with auto type P0127R2 7 4 19.14* Yes 5.0 19.0.1 19.1 11.0 11.0  10.3 17.1.0
Guaranteed copy elision P0135R1 7 4 19.13* Yes 5.0 19.0.1 19.1 11.0 11.0  10.3 17.1.0
Replacement of class objects containing reference members P0137R1 7 6 19.14* Yes 5.0 19.1 11.0 11.0  10.3 17.1.0
Stricter expression evaluation order P0145R3 7 4 19.14* Yes 5.0 19.0.1 19.1 11.0 11.0  10.3 17.1.0
Structured Bindings P0217R3 7 4 19.11* Yes 4.14 19.0 18.1 11.0* 11.0  10.3 17.1.0
Ignore unknown attributes P0283R2 Yes 3.9 19.11* Yes 4.13 18.0 17.7 11.0 11.0  10.3 17.1.0
constexpr if statements P0292R2 7 3.9 19.11* Yes 4.14 19.0 18.1 11.0 11.0  10.3 17.1.0
init-statements for if and switch P0305R1 7 3.9 19.11* Yes 4.14 18.0 18.1 11.0 11.0  10.3 17.1.0
Inline variables P0386R2 7 3.9 19.12* Yes 4.14 19.0 18.1 11.0 11.0  10.3 17.1.0
Removing dynamic exception specifications P0003R5 7 4 19.10* Yes 4.14 19.0 19.1 11.0 11.0  10.3 17.1.0
Pack expansions in using-declarations P0195R2 7 4 19.14* Yes 5.0 19.0 19.1 11.0 11.0  10.3 17.1.0
DR98: Matching of template template-arguments excludes compatible templates P0522R0 7 4 19.12* Yes 5.0 19.0.1 19.1 11.0 11.0  10.3 17.1.0
 

C++17 feature
 

Paper(s)
GCC
Clang
MSVC
Apple Clang
EDG eccp
Intel C++
Nvidia HPC C++ (ex PGI)*
Nvidia nvcc
Cray
 
Embarcadero C++ Builder
IBM Open XL C++ for AIX

[edit] C++17 library features

C++17 feature

 
Paper(s)

 
GCC libstdc++
Clang libc++
MSVC STL
Apple Clang*
 
IBM Open XL C/C++ for AIX*
Intel Parallel STL
Embarcadero C++ Builder*
std::void_t N3911 6 3.6 19.0 (2015)* Yes  17.1.0 N/A 10.3
std::uncaught_exceptions() N4259 6 3.7 19.0 (2015)* Yes  17.1.0 N/A 10.3
std::size(), std::empty() and std::data() N4280 6 3.6 19.0 (2015)* Yes  17.1.0 N/A 10.3
Improving std::pair and std::tuple N4387 6 4 19.0 (Update 2)* Yes  17.1.0 N/A 10.3
std::bool_constant N4389 6 3.7 19.0 (2015)* Yes  17.1.0 N/A 10.3
std::shared_mutex (untimed) N4508 6 3.7 19.0 (Update 2)* Yes  17.1.0 N/A 10.3
Type traits variable templates P0006R0 7 3.8 19.0 (Update 2)* Yes  17.1.0 N/A 10.3
Logical operator type traits P0013R1 6 3.8 19.0 (Update 2)* Yes  17.1.0 N/A 10.3
Parallel algorithms and execution policies P0024R2 9* 17
(partial)*
19.14*   18.0*
std::clamp() P0025R1 7 3.9 19.0 (Update 3)* 10.0.0*  17.1.0 N/A 10.3
Hardware interference size P0154R1 12 15 (partial)*
19
19.11*   N/A 10.3
(nothrow-)swappable traits P0185R1 7 3.9 19.0 (Update 3)* 10.0.0*  17.1.0 N/A 10.3
File system library (std::filesystem) P0218R1 8 7 19.14* 11.0.0*  17.1.1 N/A 10.3
std::string_view N3921
P0220R1
7 4 19.10* 10.0.0*  17.1.0 N/A 10.3
std::any P0220R1 7 4 19.10* 10.0.0*  17.1.0 N/A 10.3
std::optional P0220R1 7 4 19.10* 10.0.0*  17.1.0 N/A 10.3
Polymorphic memory resources P0220R1 9 16 19.13* 15.0.0*  N/A 10.3
Mathematical special functions P0226R1 7 19.14*   N/A 10.3
Major portion of C11 standard library P0063R3 9 7 19.0 (2015)*
(partial)*
10.0.0*  17.1.1 N/A
Splicing Maps and Sets P0083R3 7 8 19.12* 10.0.0*  17.1.1 N/A
return type of emplace* functions of some containers changed from void to reference P0084R2 7.1 4.0 19.11* Yes  17.1.0 N/A
std::variant P0088R3 7 4 19.10* 10.0.0*  17.1.0 N/A 10.3
std::make_from_tuple() P0209R2 7 3.9 19.10* Yes  17.1.0 N/A 10.3
std::has_unique_object_representations P0258R2 7 6 19.11* Yes  17.1.1 N/A 10.3
std::gcd() and std::lcm() P0295R0 7 4 19.11* Yes  17.1.0 N/A 10.3
std::not_fn P0005R4
P0358R1
7 3.9 19.12* Yes  17.1.0 N/A 10.3
Elementary string conversions: std::to_chars/std::from_chars P0067R5 8*
11
7*
14*
20*
19.14**
19.24*
10.0.0**  17.1.1* N/A 10.3*
std::shared_ptr and std::weak_ptr with array support P0414R2 7 11 19.12* 12.0.0*  17.1.1 N/A 10.3
std::scoped_lock P0156R2 7 5 19.11* Yes  17.1.1 N/A 10.3
std::byte P0298R3 7 5 19.11* Yes  17.1.1 N/A 10.3
std::is_aggregate LWG2911 7 5 19.15* Yes  17.1.1 N/A 10.3
DR17: std::hash<std::filesystem::path> LWG3657 11.4 17 19.32*   N/A
 

C++17 feature
 

Paper(s)
GCC libstdc++
Clang libc++
MSVC STL
Apple Clang*
 
IBM Open XL C/C++ for AIX*
Intel Parallel STL
Embarcadero C++ Builder*
[edit] Notes
  • As of 2020-11-20, the latest release of Oracle Developer Studio is 12.6. Its documentation does not mention C++17.
  • Cray compiler may have support for some features earlier than 11.0. That version is when it became a derivative of Clang, gaining all of the attendant language feature support of the base compiler. See Cray/HPE document S-2179.

* - hover over a cell marked with the star * to see additional pop-up notes.
DRnn - the number nn after "DR" denotes target C++ revision the Defect Report is applied to, e.g., DR20 → C++20.

[edit] External links

  C++17 - Wikipedia
  Working C++17 examples