问题
Clang has a nice page describing the project status w.r.t. C++1z/C++17 feature support (and C++11 and C++14, it's the same page).
g++ has a page regarding C++14 features, but I couldn't find anything about C++17/C++1z. Is that being worked on but just not present on the web? For version 5.0?
回答1:
As of today, gcc's C++1z language support is tracked on: https://gcc.gnu.org/projects/cxx1z.html. For the C++1z status of libstdc++, see https://gcc.gnu.org/onlinedocs/libstdc++/manual/status.html#status.iso.201z.
回答2:
There is some support already; The following two summaries are oriented on Clang's list:
Supported (as of July 5th, 2015):
autofor function parameters is supported since 4.9. This feature is currently considered an extension but is included in the concepts proposal and called "generic functions".- trigraphs are being ignored by default since 5.1.0
typenamefor template template parameters since 5.1.0- new deduction rules for direct-list-initialization since 5.1.0
static_assertwithout a message in HEADu8character literals in HEAD- Attributes for namespaces or enumerators in HEAD
Unsupported (as of July 5th, 2015; with links to a valid example usage):
- Fold expressions
- Nested namespace definitions
- Constant evaluation for all non-type template arguments
For the status of implementation of library proposals in libstdc++, the corresponding manual has a list.
回答3:
Updated final nutshell answer:
- GCC 8.x (and later) fully supports all of C++17.
- GCC 7.x supports all of C++17 except for class template argument deduction.
- GCC 6.x (and earlier) little or no support for C++17 features.
Thanks @JanVanDijk for the link to the full feature table.
回答4:
There is also a nice table at cppreference.com that lists supported features for several compilers.
http://en.cppreference.com/w/cpp/compiler_support
来源：https://stackoverflow.com/questions/31230201/whats-the-status-of-c17-support-in-gcc